Add lc-proxy-wrapper dep

Makefile

@@ -165,6 +165,7 @@ statusgo-shared-library: ##@cross-compile Build status-go as shared library for
 	mkdir -p build/bin/statusgo-lib
 	go run cmd/library/*.go > build/bin/statusgo-lib/main.go
 	@echo "Building shared library..."
+	@echo "Tags: $(BUILD_TAGS)"
 	$(GOBIN_SHARED_LIB_CFLAGS) $(GOBIN_SHARED_LIB_CGO_LDFLAGS) go build \
 		-tags '$(BUILD_TAGS)' \
 		$(BUILD_FLAGS) \
@@ -389,3 +390,16 @@ migration:
 migration-protocol: DEFAULT_PROTOCOL_PATH := protocol/migrations/sqlite
 migration-protocol:
 	touch $(DEFAULT_PROTOCOL_PATH)/$(shell date +%s)_$(D).up.sql
+
+PROXY_WRAPPER_PATH = $(CURDIR)/vendor/github.com/siphiuel/lc-proxy-wrapper
+-include $(PROXY_WRAPPER_PATH)/Makefile.vars
+
+#export VERIF_PROXY_OUT_PATH = $(CURDIR)/vendor/github.com/siphiuel/lc-proxy-wrapper
+build-verif-proxy:
+	$(MAKE) -C $(NIMBUS_ETH1_PATH) libverifproxy
+
+build-verif-proxy-wrapper:
+	$(MAKE) -C $(VERIF_PROXY_OUT_PATH) build-verif-proxy-wrapper
+
+test-verif-proxy-wrapper:
+	CGO_CFLAGS="$(CGO_CFLAGS)" go test -v github.com/status-im/status-go/rpc -tags gowaku_skip_migrations,nimbus_light_client -run ^TestProxySuite$$ -testify.m TestRun -ldflags $(LDFLAGS)

VERSION

@@ -1 +1 @@
-0.151.15
+0.151.16

go.mod

@@ -81,14 +81,17 @@ require (
 	github.com/ladydascalie/currency v1.6.0
 	github.com/meirf/gopart v0.0.0-20180520194036-37e9492a85a8
 	github.com/schollz/peerdiscovery v1.7.0
+	github.com/siphiuel/lc-proxy-wrapper v0.0.0-20230516150924-246507cee8c7
 	github.com/waku-org/go-waku v0.6.0
 	github.com/yeqown/go-qrcode/v2 v2.2.1
 	github.com/yeqown/go-qrcode/writer/standard v1.2.1
 	go.uber.org/multierr v1.8.0
+	golang.org/x/exp v0.0.0-20230206171751-46f607a40771
 	golang.org/x/net v0.8.0
 )
 
 require (
+	github.com/BurntSushi/toml v1.2.1 // indirect
 	github.com/PuerkitoBio/goquery v1.6.1 // indirect
 	github.com/RoaringBitmap/roaring v0.9.4 // indirect
 	github.com/StackExchange/wmi v0.0.0-20210224194228-fe8f1750fd46 // indirect
@@ -258,7 +261,6 @@ require (
 	go.uber.org/atomic v1.10.0 // indirect
 	go.uber.org/dig v1.15.0 // indirect
 	go.uber.org/fx v1.18.2 // indirect
-	golang.org/x/exp v0.0.0-20230206171751-46f607a40771 // indirect
 	golang.org/x/mod v0.8.0 // indirect
 	golang.org/x/sync v0.1.0 // indirect
 	golang.org/x/sys v0.6.0 // indirect

go.sum

@@ -105,6 +105,7 @@ github.com/Azure/go-autorest/tracing v0.5.0/go.mod h1:r/s2XiOKccPW3HrqB+W0TQzfbt
 github.com/Azure/go-autorest/tracing v0.6.0/go.mod h1:+vhtPC754Xsa23ID7GlGsrdKBpUA79WCAKPPZVC2DeU=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/toml v1.2.1 h1:9F2/+DoOYIOksmaJFPw1tGFy1eDnIJXg+UHjuD8lTak=
+github.com/BurntSushi/toml v1.2.1/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/ClickHouse/clickhouse-go v1.4.3/go.mod h1:EaI/sW7Azgz9UATzd5ZdZHRUhHgv5+JMS9NSr2smCJI=
 github.com/DATA-DOG/go-sqlmock v1.3.3/go.mod h1:f/Ixk793poVmq4qj/V1dPUg2JEAKC73Q5eFN3EC/SaM=
@@ -1941,6 +1942,8 @@ github.com/shurcooL/sanitized_anchor_name v0.0.0-20170918181015-86672fcb3f95/go.
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/shurcooL/users v0.0.0-20180125191416-49c67e49c537/go.mod h1:QJTqeLYEDaXHZDBsXlPCDqdhQuJkuw4NOtaxYe3xii4=
 github.com/shurcooL/webdavfs v0.0.0-20170829043945-18c3829fa133/go.mod h1:hKmq5kWdCj2z2KEozexVbfEZIWiTjhE0+UjmZgPqehw=
+github.com/siphiuel/lc-proxy-wrapper v0.0.0-20230516150924-246507cee8c7 h1:l7v5b3ghketKidVR6QjJlsgrrgzRnRRCc0lywjjONjQ=
+github.com/siphiuel/lc-proxy-wrapper v0.0.0-20230516150924-246507cee8c7/go.mod h1:Cpir2acMsYVjrwbmRKN+2w1mYbBZdWwmoIyqc7x470U=
 github.com/sirupsen/logrus v1.0.4-0.20170822132746-89742aefa4b2/go.mod h1:pMByvHTf9Beacp5x1UXfOR9xyW/9antXMhjMPG0dEzc=
 github.com/sirupsen/logrus v1.0.6/go.mod h1:pMByvHTf9Beacp5x1UXfOR9xyW/9antXMhjMPG0dEzc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=

params/defaults.go

@@ -9,6 +9,8 @@ const (
 	// SendTransactionMethodName defines the name for a giving transaction.
 	SendTransactionMethodName = "eth_sendTransaction"
 
+	BalanceMethodName = "eth_getBalance"
+
 	// AccountsMethodName defines the name for listing the currently signed accounts.
 	AccountsMethodName = "eth_accounts"
 

rpc/client.go

@@ -56,6 +56,9 @@ type Client struct {
 	walletNotifier func(chainID uint64, message string)
 }
 
+// Is initialized in a build-tag-dependent module
+var verifProxyInitFn func(c *Client)
+
 // NewClient initializes Client and tries to connect to both,
 // upstream and local node.
 //
@@ -92,6 +95,10 @@ func NewClient(client *gethrpc.Client, upstreamChainID uint64, upstream params.U
 
 	c.router = newRouter(c.upstreamEnabled)
 
+	if verifProxyInitFn != nil {
+		verifProxyInitFn(&c)
+	}
+
 	return &c, nil
 }
 
@@ -247,6 +254,14 @@ func (c *Client) RegisterHandler(method string, handler Handler) {
 	c.handlers[method] = handler
 }
 
+// UnregisterHandler removes a previously registered handler.
+func (c *Client) UnregisterHandler(method string) {
+	c.handlersMx.Lock()
+	defer c.handlersMx.Unlock()
+
+	delete(c.handlers, method)
+}
+
 // callMethod calls registered RPC handler with given args and pointer to result.
 // It handles proper params and result converting
 //

rpc/verif_proxy.go

@@ -0,0 +1,71 @@
+//go:build nimbus_light_client
+// +build nimbus_light_client
+
+package rpc
+
+import (
+	"context"
+	"fmt"
+)
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/log"
+	gethrpc "github.com/ethereum/go-ethereum/rpc"
+	proxy "github.com/siphiuel/lc-proxy-wrapper"
+	"github.com/status-im/status-go/params"
+)
+
+type VerifProxy struct {
+	config *proxy.Config
+	client *gethrpc.Client
+	log    log.Logger
+}
+
+func init() {
+	verifProxyInitFn = func(c *Client) {
+		ctx := context.Background()
+		var testConfig = proxy.Config{
+			Eth2Network:      "mainnet",
+			TrustedBlockRoot: "0xc5182cdb750fe088138b0d475683cda26a96befc24de16fb17bcf49d9cadf2f7",
+			Web3Url:          c.upstreamURL,
+			RpcAddress:       "127.0.0.1",
+			RpcPort:          8545,
+			LogLevel:         "INFO",
+		}
+		proxy.StartLightClient(ctx, &testConfig)
+		verifProxy, err := newVerifProxy(&testConfig, c.log)
+		if err != nil {
+			c.RegisterHandler(
+				params.BalanceMethodName,
+				func(ctx context.Context, v uint64, params ...interface{}) (interface{}, error) {
+					addr := params[0].(common.Address)
+					return verifProxy.GetBalance(ctx, addr)
+				},
+			)
+		}
+	}
+}
+
+func newVerifProxy(cfg *proxy.Config, log log.Logger) (*VerifProxy, error) {
+	endpoint := "http://" + cfg.RpcAddress + ":" + fmt.Sprint(cfg.RpcPort)
+	client, err := gethrpc.DialHTTP(endpoint)
+	if err != nil {
+		log.Error("Error when creating VerifProxy client", err)
+		return nil, err
+	}
+	proxy := &VerifProxy{cfg, client, log}
+	return proxy, nil
+}
+
+func (p *VerifProxy) GetBalance(ctx context.Context, address common.Address) (interface{}, error) {
+	var result hexutil.Big
+	err := p.client.CallContext(ctx, &result, "eth_getBalance", address, "latest")
+	if err != nil {
+		p.log.Error("Error when invoking GetBalance", err)
+		return nil, err
+	}
+	return result, nil
+
+}

rpc/verif_proxy_test.go

@@ -0,0 +1,89 @@
+//go:build nimbus_light_client
+// +build nimbus_light_client
+
+package rpc
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+	"testing"
+	"time"
+
+	"net/http"
+	"net/http/httptest"
+)
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	gethrpc "github.com/ethereum/go-ethereum/rpc"
+	"github.com/status-im/status-go/params"
+
+	"github.com/stretchr/testify/require"
+	"github.com/stretchr/testify/suite"
+)
+
+type ProxySuite struct {
+	suite.Suite
+}
+
+func TestProxySuite(t *testing.T) {
+	suite.Run(t, new(ProxySuite))
+}
+
+func (s *ProxySuite) startRpcClient(infuraURL string) *Client {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprintln(w, `{
+			"id": 1,
+			"jsonrpc": "2.0",
+			"result": "0x234234e22b9ffc2387e18636e0534534a3d0c56b0243567432453264c16e78a2adc"
+		}`)
+	}))
+	defer ts.Close()
+
+	gethRPCClient, err := gethrpc.Dial(ts.URL)
+	require.NoError(s.T(), err)
+
+	db, close := setupTestNetworkDB(s.T())
+	defer close()
+	c, err := NewClient(gethRPCClient, 1, params.UpstreamRPCConfig{Enabled: true, URL: infuraURL}, []params.Network{}, db)
+	require.NoError(s.T(), err)
+
+	return c
+}
+
+func (s *ProxySuite) TestRun() {
+	infuraURL := "https://mainnet.infura.io/v3/800c641949d64d768a5070a1b0511938"
+	client := s.startRpcClient(infuraURL)
+
+	// Run light client proxy
+	ctx, cancel := context.WithCancel(context.Background())
+
+	signals := make(chan os.Signal, 1)
+	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)
+	fmt.Println("Before range signals")
+
+	// Invoke eth_getBalance
+	var result hexutil.Big
+	var addr common.Address
+	addr = common.HexToAddress("0x95222290DD7278Aa3Ddd389Cc1E1d165CC4BAfe5")
+	chainID := uint64(1)
+
+	time.Sleep(200 * time.Second)
+	err := client.CallContext(ctx, &result, chainID, "eth_getBalance", addr, "latest")
+	require.NoError(s.T(), err)
+
+	client.UnregisterHandler("eth_getBalance")
+	var resultRaw hexutil.Big
+	err = client.CallContext(ctx, &resultRaw, chainID, "eth_getBalance", addr, "latest")
+	s.Require().Equal(result, resultRaw)
+	for range signals {
+		fmt.Println("Signal caught, exiting")
+		cancel()
+	}
+	fmt.Println("Exiting")
+
+}

vendor/github.com/BurntSushi/toml/.gitignore

@@ -0,0 +1,2 @@
+/toml.test
+/toml-test

vendor/github.com/BurntSushi/toml/COPYING

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2013 TOML authors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

vendor/github.com/BurntSushi/toml/README.md

@@ -0,0 +1,120 @@
+TOML stands for Tom's Obvious, Minimal Language. This Go package provides a
+reflection interface similar to Go's standard library `json` and `xml` packages.
+
+Compatible with TOML version [v1.0.0](https://toml.io/en/v1.0.0).
+
+Documentation: https://godocs.io/github.com/BurntSushi/toml
+
+See the [releases page](https://github.com/BurntSushi/toml/releases) for a
+changelog; this information is also in the git tag annotations (e.g. `git show
+v0.4.0`).
+
+This library requires Go 1.13 or newer; add it to your go.mod with:
+
+    % go get github.com/BurntSushi/toml@latest
+
+It also comes with a TOML validator CLI tool:
+
+    % go install github.com/BurntSushi/toml/cmd/tomlv@latest
+    % tomlv some-toml-file.toml
+
+### Examples
+For the simplest example, consider some TOML file as just a list of keys and
+values:
+
+```toml
+Age = 25
+Cats = [ "Cauchy", "Plato" ]
+Pi = 3.14
+Perfection = [ 6, 28, 496, 8128 ]
+DOB = 1987-07-05T05:45:00Z
+```
+
+Which can be decoded with:
+
+```go
+type Config struct {
+	Age        int
+	Cats       []string
+	Pi         float64
+	Perfection []int
+	DOB        time.Time
+}
+
+var conf Config
+_, err := toml.Decode(tomlData, &conf)
+```
+
+You can also use struct tags if your struct field name doesn't map to a TOML key
+value directly:
+
+```toml
+some_key_NAME = "wat"
+```
+
+```go
+type TOML struct {
+    ObscureKey string `toml:"some_key_NAME"`
+}
+```
+
+Beware that like other decoders **only exported fields** are considered when
+encoding and decoding; private fields are silently ignored.
+
+### Using the `Marshaler` and `encoding.TextUnmarshaler` interfaces
+Here's an example that automatically parses values in a `mail.Address`:
+
+```toml
+contacts = [
+    "Donald Duck <donald@duckburg.com>",
+    "Scrooge McDuck <scrooge@duckburg.com>",
+]
+```
+
+Can be decoded with:
+
+```go
+// Create address type which satisfies the encoding.TextUnmarshaler interface.
+type address struct {
+	*mail.Address
+}
+
+func (a *address) UnmarshalText(text []byte) error {
+	var err error
+	a.Address, err = mail.ParseAddress(string(text))
+	return err
+}
+
+// Decode it.
+func decode() {
+	blob := `
+		contacts = [
+			"Donald Duck <donald@duckburg.com>",
+			"Scrooge McDuck <scrooge@duckburg.com>",
+		]
+	`
+
+	var contacts struct {
+		Contacts []address
+	}
+
+	_, err := toml.Decode(blob, &contacts)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, c := range contacts.Contacts {
+		fmt.Printf("%#v\n", c.Address)
+	}
+
+	// Output:
+	// &mail.Address{Name:"Donald Duck", Address:"donald@duckburg.com"}
+	// &mail.Address{Name:"Scrooge McDuck", Address:"scrooge@duckburg.com"}
+}
+```
+
+To target TOML specifically you can implement `UnmarshalTOML` TOML interface in
+a similar way.
+
+### More complex usage
+See the [`_example/`](/_example) directory for a more complex example.

vendor/github.com/BurntSushi/toml/decode.go

@@ -0,0 +1,602 @@
+package toml
+
+import (
+	"bytes"
+	"encoding"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"math"
+	"os"
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Unmarshaler is the interface implemented by objects that can unmarshal a
+// TOML description of themselves.
+type Unmarshaler interface {
+	UnmarshalTOML(interface{}) error
+}
+
+// Unmarshal decodes the contents of data in TOML format into a pointer v.
+//
+// See [Decoder] for a description of the decoding process.
+func Unmarshal(data []byte, v interface{}) error {
+	_, err := NewDecoder(bytes.NewReader(data)).Decode(v)
+	return err
+}
+
+// Decode the TOML data in to the pointer v.
+//
+// See [Decoder] for a description of the decoding process.
+func Decode(data string, v interface{}) (MetaData, error) {
+	return NewDecoder(strings.NewReader(data)).Decode(v)
+}
+
+// DecodeFile reads the contents of a file and decodes it with [Decode].
+func DecodeFile(path string, v interface{}) (MetaData, error) {
+	fp, err := os.Open(path)
+	if err != nil {
+		return MetaData{}, err
+	}
+	defer fp.Close()
+	return NewDecoder(fp).Decode(v)
+}
+
+// Primitive is a TOML value that hasn't been decoded into a Go value.
+//
+// This type can be used for any value, which will cause decoding to be delayed.
+// You can use [PrimitiveDecode] to "manually" decode these values.
+//
+// NOTE: The underlying representation of a `Primitive` value is subject to
+// change. Do not rely on it.
+//
+// NOTE: Primitive values are still parsed, so using them will only avoid the
+// overhead of reflection. They can be useful when you don't know the exact type
+// of TOML data until runtime.
+type Primitive struct {
+	undecoded interface{}
+	context   Key
+}
+
+// The significand precision for float32 and float64 is 24 and 53 bits; this is
+// the range a natural number can be stored in a float without loss of data.
+const (
+	maxSafeFloat32Int = 16777215                // 2^24-1
+	maxSafeFloat64Int = int64(9007199254740991) // 2^53-1
+)
+
+// Decoder decodes TOML data.
+//
+// TOML tables correspond to Go structs or maps; they can be used
+// interchangeably, but structs offer better type safety.
+//
+// TOML table arrays correspond to either a slice of structs or a slice of maps.
+//
+// TOML datetimes correspond to [time.Time]. Local datetimes are parsed in the
+// local timezone.
+//
+// [time.Duration] types are treated as nanoseconds if the TOML value is an
+// integer, or they're parsed with time.ParseDuration() if they're strings.
+//
+// All other TOML types (float, string, int, bool and array) correspond to the
+// obvious Go types.
+//
+// An exception to the above rules is if a type implements the TextUnmarshaler
+// interface, in which case any primitive TOML value (floats, strings, integers,
+// booleans, datetimes) will be converted to a []byte and given to the value's
+// UnmarshalText method. See the Unmarshaler example for a demonstration with
+// email addresses.
+//
+// ### Key mapping
+//
+// TOML keys can map to either keys in a Go map or field names in a Go struct.
+// The special `toml` struct tag can be used to map TOML keys to struct fields
+// that don't match the key name exactly (see the example). A case insensitive
+// match to struct names will be tried if an exact match can't be found.
+//
+// The mapping between TOML values and Go values is loose. That is, there may
+// exist TOML values that cannot be placed into your representation, and there
+// may be parts of your representation that do not correspond to TOML values.
+// This loose mapping can be made stricter by using the IsDefined and/or
+// Undecoded methods on the MetaData returned.
+//
+// This decoder does not handle cyclic types. Decode will not terminate if a
+// cyclic type is passed.
+type Decoder struct {
+	r io.Reader
+}
+
+// NewDecoder creates a new Decoder.
+func NewDecoder(r io.Reader) *Decoder {
+	return &Decoder{r: r}
+}
+
+var (
+	unmarshalToml = reflect.TypeOf((*Unmarshaler)(nil)).Elem()
+	unmarshalText = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
+	primitiveType = reflect.TypeOf((*Primitive)(nil)).Elem()
+)
+
+// Decode TOML data in to the pointer `v`.
+func (dec *Decoder) Decode(v interface{}) (MetaData, error) {
+	rv := reflect.ValueOf(v)
+	if rv.Kind() != reflect.Ptr {
+		s := "%q"
+		if reflect.TypeOf(v) == nil {
+			s = "%v"
+		}
+
+		return MetaData{}, fmt.Errorf("toml: cannot decode to non-pointer "+s, reflect.TypeOf(v))
+	}
+	if rv.IsNil() {
+		return MetaData{}, fmt.Errorf("toml: cannot decode to nil value of %q", reflect.TypeOf(v))
+	}
+
+	// Check if this is a supported type: struct, map, interface{}, or something
+	// that implements UnmarshalTOML or UnmarshalText.
+	rv = indirect(rv)
+	rt := rv.Type()
+	if rv.Kind() != reflect.Struct && rv.Kind() != reflect.Map &&
+		!(rv.Kind() == reflect.Interface && rv.NumMethod() == 0) &&
+		!rt.Implements(unmarshalToml) && !rt.Implements(unmarshalText) {
+		return MetaData{}, fmt.Errorf("toml: cannot decode to type %s", rt)
+	}
+
+	// TODO: parser should read from io.Reader? Or at the very least, make it
+	// read from []byte rather than string
+	data, err := ioutil.ReadAll(dec.r)
+	if err != nil {
+		return MetaData{}, err
+	}
+
+	p, err := parse(string(data))
+	if err != nil {
+		return MetaData{}, err
+	}
+
+	md := MetaData{
+		mapping: p.mapping,
+		keyInfo: p.keyInfo,
+		keys:    p.ordered,
+		decoded: make(map[string]struct{}, len(p.ordered)),
+		context: nil,
+		data:    data,
+	}
+	return md, md.unify(p.mapping, rv)
+}
+
+// PrimitiveDecode is just like the other Decode* functions, except it decodes a
+// TOML value that has already been parsed. Valid primitive values can *only* be
+// obtained from values filled by the decoder functions, including this method.
+// (i.e., v may contain more [Primitive] values.)
+//
+// Meta data for primitive values is included in the meta data returned by the
+// Decode* functions with one exception: keys returned by the Undecoded method
+// will only reflect keys that were decoded. Namely, any keys hidden behind a
+// Primitive will be considered undecoded. Executing this method will update the
+// undecoded keys in the meta data. (See the example.)
+func (md *MetaData) PrimitiveDecode(primValue Primitive, v interface{}) error {
+	md.context = primValue.context
+	defer func() { md.context = nil }()
+	return md.unify(primValue.undecoded, rvalue(v))
+}
+
+// unify performs a sort of type unification based on the structure of `rv`,
+// which is the client representation.
+//
+// Any type mismatch produces an error. Finding a type that we don't know
+// how to handle produces an unsupported type error.
+func (md *MetaData) unify(data interface{}, rv reflect.Value) error {
+	// Special case. Look for a `Primitive` value.
+	// TODO: #76 would make this superfluous after implemented.
+	if rv.Type() == primitiveType {
+		// Save the undecoded data and the key context into the primitive
+		// value.
+		context := make(Key, len(md.context))
+		copy(context, md.context)
+		rv.Set(reflect.ValueOf(Primitive{
+			undecoded: data,
+			context:   context,
+		}))
+		return nil
+	}
+
+	rvi := rv.Interface()
+	if v, ok := rvi.(Unmarshaler); ok {
+		return v.UnmarshalTOML(data)
+	}
+	if v, ok := rvi.(encoding.TextUnmarshaler); ok {
+		return md.unifyText(data, v)
+	}
+
+	// TODO:
+	// The behavior here is incorrect whenever a Go type satisfies the
+	// encoding.TextUnmarshaler interface but also corresponds to a TOML hash or
+	// array. In particular, the unmarshaler should only be applied to primitive
+	// TOML values. But at this point, it will be applied to all kinds of values
+	// and produce an incorrect error whenever those values are hashes or arrays
+	// (including arrays of tables).
+
+	k := rv.Kind()
+
+	if k >= reflect.Int && k <= reflect.Uint64 {
+		return md.unifyInt(data, rv)
+	}
+	switch k {
+	case reflect.Ptr:
+		elem := reflect.New(rv.Type().Elem())
+		err := md.unify(data, reflect.Indirect(elem))
+		if err != nil {
+			return err
+		}
+		rv.Set(elem)
+		return nil
+	case reflect.Struct:
+		return md.unifyStruct(data, rv)
+	case reflect.Map:
+		return md.unifyMap(data, rv)
+	case reflect.Array:
+		return md.unifyArray(data, rv)
+	case reflect.Slice:
+		return md.unifySlice(data, rv)
+	case reflect.String:
+		return md.unifyString(data, rv)
+	case reflect.Bool:
+		return md.unifyBool(data, rv)
+	case reflect.Interface:
+		if rv.NumMethod() > 0 { // Only support empty interfaces are supported.
+			return md.e("unsupported type %s", rv.Type())
+		}
+		return md.unifyAnything(data, rv)
+	case reflect.Float32, reflect.Float64:
+		return md.unifyFloat64(data, rv)
+	}
+	return md.e("unsupported type %s", rv.Kind())
+}
+
+func (md *MetaData) unifyStruct(mapping interface{}, rv reflect.Value) error {
+	tmap, ok := mapping.(map[string]interface{})
+	if !ok {
+		if mapping == nil {
+			return nil
+		}
+		return md.e("type mismatch for %s: expected table but found %T",
+			rv.Type().String(), mapping)
+	}
+
+	for key, datum := range tmap {
+		var f *field
+		fields := cachedTypeFields(rv.Type())
+		for i := range fields {
+			ff := &fields[i]
+			if ff.name == key {
+				f = ff
+				break
+			}
+			if f == nil && strings.EqualFold(ff.name, key) {
+				f = ff
+			}
+		}
+		if f != nil {
+			subv := rv
+			for _, i := range f.index {
+				subv = indirect(subv.Field(i))
+			}
+
+			if isUnifiable(subv) {
+				md.decoded[md.context.add(key).String()] = struct{}{}
+				md.context = append(md.context, key)
+
+				err := md.unify(datum, subv)
+				if err != nil {
+					return err
+				}
+				md.context = md.context[0 : len(md.context)-1]
+			} else if f.name != "" {
+				return md.e("cannot write unexported field %s.%s", rv.Type().String(), f.name)
+			}
+		}
+	}
+	return nil
+}
+
+func (md *MetaData) unifyMap(mapping interface{}, rv reflect.Value) error {
+	keyType := rv.Type().Key().Kind()
+	if keyType != reflect.String && keyType != reflect.Interface {
+		return fmt.Errorf("toml: cannot decode to a map with non-string key type (%s in %q)",
+			keyType, rv.Type())
+	}
+
+	tmap, ok := mapping.(map[string]interface{})
+	if !ok {
+		if tmap == nil {
+			return nil
+		}
+		return md.badtype("map", mapping)
+	}
+	if rv.IsNil() {
+		rv.Set(reflect.MakeMap(rv.Type()))
+	}
+	for k, v := range tmap {
+		md.decoded[md.context.add(k).String()] = struct{}{}
+		md.context = append(md.context, k)
+
+		rvval := reflect.Indirect(reflect.New(rv.Type().Elem()))
+
+		err := md.unify(v, indirect(rvval))
+		if err != nil {
+			return err
+		}
+		md.context = md.context[0 : len(md.context)-1]
+
+		rvkey := indirect(reflect.New(rv.Type().Key()))
+
+		switch keyType {
+		case reflect.Interface:
+			rvkey.Set(reflect.ValueOf(k))
+		case reflect.String:
+			rvkey.SetString(k)
+		}
+
+		rv.SetMapIndex(rvkey, rvval)
+	}
+	return nil
+}
+
+func (md *MetaData) unifyArray(data interface{}, rv reflect.Value) error {
+	datav := reflect.ValueOf(data)
+	if datav.Kind() != reflect.Slice {
+		if !datav.IsValid() {
+			return nil
+		}
+		return md.badtype("slice", data)
+	}
+	if l := datav.Len(); l != rv.Len() {
+		return md.e("expected array length %d; got TOML array of length %d", rv.Len(), l)
+	}
+	return md.unifySliceArray(datav, rv)
+}
+
+func (md *MetaData) unifySlice(data interface{}, rv reflect.Value) error {
+	datav := reflect.ValueOf(data)
+	if datav.Kind() != reflect.Slice {
+		if !datav.IsValid() {
+			return nil
+		}
+		return md.badtype("slice", data)
+	}
+	n := datav.Len()
+	if rv.IsNil() || rv.Cap() < n {
+		rv.Set(reflect.MakeSlice(rv.Type(), n, n))
+	}
+	rv.SetLen(n)
+	return md.unifySliceArray(datav, rv)
+}
+
+func (md *MetaData) unifySliceArray(data, rv reflect.Value) error {
+	l := data.Len()
+	for i := 0; i < l; i++ {
+		err := md.unify(data.Index(i).Interface(), indirect(rv.Index(i)))
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (md *MetaData) unifyString(data interface{}, rv reflect.Value) error {
+	_, ok := rv.Interface().(json.Number)
+	if ok {
+		if i, ok := data.(int64); ok {
+			rv.SetString(strconv.FormatInt(i, 10))
+		} else if f, ok := data.(float64); ok {
+			rv.SetString(strconv.FormatFloat(f, 'f', -1, 64))
+		} else {
+			return md.badtype("string", data)
+		}
+		return nil
+	}
+
+	if s, ok := data.(string); ok {
+		rv.SetString(s)
+		return nil
+	}
+	return md.badtype("string", data)
+}
+
+func (md *MetaData) unifyFloat64(data interface{}, rv reflect.Value) error {
+	rvk := rv.Kind()
+
+	if num, ok := data.(float64); ok {
+		switch rvk {
+		case reflect.Float32:
+			if num < -math.MaxFloat32 || num > math.MaxFloat32 {
+				return md.parseErr(errParseRange{i: num, size: rvk.String()})
+			}
+			fallthrough
+		case reflect.Float64:
+			rv.SetFloat(num)
+		default:
+			panic("bug")
+		}
+		return nil
+	}
+
+	if num, ok := data.(int64); ok {
+		if (rvk == reflect.Float32 && (num < -maxSafeFloat32Int || num > maxSafeFloat32Int)) ||
+			(rvk == reflect.Float64 && (num < -maxSafeFloat64Int || num > maxSafeFloat64Int)) {
+			return md.parseErr(errParseRange{i: num, size: rvk.String()})
+		}
+		rv.SetFloat(float64(num))
+		return nil
+	}
+
+	return md.badtype("float", data)
+}
+
+func (md *MetaData) unifyInt(data interface{}, rv reflect.Value) error {
+	_, ok := rv.Interface().(time.Duration)
+	if ok {
+		// Parse as string duration, and fall back to regular integer parsing
+		// (as nanosecond) if this is not a string.
+		if s, ok := data.(string); ok {
+			dur, err := time.ParseDuration(s)
+			if err != nil {
+				return md.parseErr(errParseDuration{s})
+			}
+			rv.SetInt(int64(dur))
+			return nil
+		}
+	}
+
+	num, ok := data.(int64)
+	if !ok {
+		return md.badtype("integer", data)
+	}
+
+	rvk := rv.Kind()
+	switch {
+	case rvk >= reflect.Int && rvk <= reflect.Int64:
+		if (rvk == reflect.Int8 && (num < math.MinInt8 || num > math.MaxInt8)) ||
+			(rvk == reflect.Int16 && (num < math.MinInt16 || num > math.MaxInt16)) ||
+			(rvk == reflect.Int32 && (num < math.MinInt32 || num > math.MaxInt32)) {
+			return md.parseErr(errParseRange{i: num, size: rvk.String()})
+		}
+		rv.SetInt(num)
+	case rvk >= reflect.Uint && rvk <= reflect.Uint64:
+		unum := uint64(num)
+		if rvk == reflect.Uint8 && (num < 0 || unum > math.MaxUint8) ||
+			rvk == reflect.Uint16 && (num < 0 || unum > math.MaxUint16) ||
+			rvk == reflect.Uint32 && (num < 0 || unum > math.MaxUint32) {
+			return md.parseErr(errParseRange{i: num, size: rvk.String()})
+		}
+		rv.SetUint(unum)
+	default:
+		panic("unreachable")
+	}
+	return nil
+}
+
+func (md *MetaData) unifyBool(data interface{}, rv reflect.Value) error {
+	if b, ok := data.(bool); ok {
+		rv.SetBool(b)
+		return nil
+	}
+	return md.badtype("boolean", data)
+}
+
+func (md *MetaData) unifyAnything(data interface{}, rv reflect.Value) error {
+	rv.Set(reflect.ValueOf(data))
+	return nil
+}
+
+func (md *MetaData) unifyText(data interface{}, v encoding.TextUnmarshaler) error {
+	var s string
+	switch sdata := data.(type) {
+	case Marshaler:
+		text, err := sdata.MarshalTOML()
+		if err != nil {
+			return err
+		}
+		s = string(text)
+	case encoding.TextMarshaler:
+		text, err := sdata.MarshalText()
+		if err != nil {
+			return err
+		}
+		s = string(text)
+	case fmt.Stringer:
+		s = sdata.String()
+	case string:
+		s = sdata
+	case bool:
+		s = fmt.Sprintf("%v", sdata)
+	case int64:
+		s = fmt.Sprintf("%d", sdata)
+	case float64:
+		s = fmt.Sprintf("%f", sdata)
+	default:
+		return md.badtype("primitive (string-like)", data)
+	}
+	if err := v.UnmarshalText([]byte(s)); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (md *MetaData) badtype(dst string, data interface{}) error {
+	return md.e("incompatible types: TOML value has type %T; destination has type %s", data, dst)
+}
+
+func (md *MetaData) parseErr(err error) error {
+	k := md.context.String()
+	return ParseError{
+		LastKey:  k,
+		Position: md.keyInfo[k].pos,
+		Line:     md.keyInfo[k].pos.Line,
+		err:      err,
+		input:    string(md.data),
+	}
+}
+
+func (md *MetaData) e(format string, args ...interface{}) error {
+	f := "toml: "
+	if len(md.context) > 0 {
+		f = fmt.Sprintf("toml: (last key %q): ", md.context)
+		p := md.keyInfo[md.context.String()].pos
+		if p.Line > 0 {
+			f = fmt.Sprintf("toml: line %d (last key %q): ", p.Line, md.context)
+		}
+	}
+	return fmt.Errorf(f+format, args...)
+}
+
+// rvalue returns a reflect.Value of `v`. All pointers are resolved.
+func rvalue(v interface{}) reflect.Value {
+	return indirect(reflect.ValueOf(v))
+}
+
+// indirect returns the value pointed to by a pointer.
+//
+// Pointers are followed until the value is not a pointer. New values are
+// allocated for each nil pointer.
+//
+// An exception to this rule is if the value satisfies an interface of interest
+// to us (like encoding.TextUnmarshaler).
+func indirect(v reflect.Value) reflect.Value {
+	if v.Kind() != reflect.Ptr {
+		if v.CanSet() {
+			pv := v.Addr()
+			pvi := pv.Interface()
+			if _, ok := pvi.(encoding.TextUnmarshaler); ok {
+				return pv
+			}
+			if _, ok := pvi.(Unmarshaler); ok {
+				return pv
+			}
+		}
+		return v
+	}
+	if v.IsNil() {
+		v.Set(reflect.New(v.Type().Elem()))
+	}
+	return indirect(reflect.Indirect(v))
+}
+
+func isUnifiable(rv reflect.Value) bool {
+	if rv.CanSet() {
+		return true
+	}
+	rvi := rv.Interface()
+	if _, ok := rvi.(encoding.TextUnmarshaler); ok {
+		return true
+	}
+	if _, ok := rvi.(Unmarshaler); ok {
+		return true
+	}
+	return false
+}

vendor/github.com/BurntSushi/toml/decode_go116.go

@@ -0,0 +1,19 @@
+//go:build go1.16
+// +build go1.16
+
+package toml
+
+import (
+	"io/fs"
+)
+
+// DecodeFS reads the contents of a file from [fs.FS] and decodes it with
+// [Decode].
+func DecodeFS(fsys fs.FS, path string, v interface{}) (MetaData, error) {
+	fp, err := fsys.Open(path)
+	if err != nil {
+		return MetaData{}, err
+	}
+	defer fp.Close()
+	return NewDecoder(fp).Decode(v)
+}

vendor/github.com/BurntSushi/toml/deprecated.go

@@ -0,0 +1,21 @@
+package toml
+
+import (
+	"encoding"
+	"io"
+)
+
+// Deprecated: use encoding.TextMarshaler
+type TextMarshaler encoding.TextMarshaler
+
+// Deprecated: use encoding.TextUnmarshaler
+type TextUnmarshaler encoding.TextUnmarshaler
+
+// Deprecated: use MetaData.PrimitiveDecode.
+func PrimitiveDecode(primValue Primitive, v interface{}) error {
+	md := MetaData{decoded: make(map[string]struct{})}
+	return md.unify(primValue.undecoded, rvalue(v))
+}
+
+// Deprecated: use NewDecoder(reader).Decode(&value).
+func DecodeReader(r io.Reader, v interface{}) (MetaData, error) { return NewDecoder(r).Decode(v) }

vendor/github.com/BurntSushi/toml/doc.go

@@ -0,0 +1,11 @@
+// Package toml implements decoding and encoding of TOML files.
+//
+// This package supports TOML v1.0.0, as specified at https://toml.io
+//
+// There is also support for delaying decoding with the Primitive type, and
+// querying the set of keys in a TOML document with the MetaData type.
+//
+// The github.com/BurntSushi/toml/cmd/tomlv package implements a TOML validator,
+// and can be used to verify if TOML document is valid. It can also be used to
+// print the type of each key.
+package toml

vendor/github.com/BurntSushi/toml/encode.go

@@ -0,0 +1,750 @@
+package toml
+
+import (
+	"bufio"
+	"encoding"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"math"
+	"reflect"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/BurntSushi/toml/internal"
+)
+
+type tomlEncodeError struct{ error }
+
+var (
+	errArrayNilElement = errors.New("toml: cannot encode array with nil element")
+	errNonString       = errors.New("toml: cannot encode a map with non-string key type")
+	errNoKey           = errors.New("toml: top-level values must be Go maps or structs")
+	errAnything        = errors.New("") // used in testing
+)
+
+var dblQuotedReplacer = strings.NewReplacer(
+	"\"", "\\\"",
+	"\\", "\\\\",
+	"\x00", `\u0000`,
+	"\x01", `\u0001`,
+	"\x02", `\u0002`,
+	"\x03", `\u0003`,
+	"\x04", `\u0004`,
+	"\x05", `\u0005`,
+	"\x06", `\u0006`,
+	"\x07", `\u0007`,
+	"\b", `\b`,
+	"\t", `\t`,
+	"\n", `\n`,
+	"\x0b", `\u000b`,
+	"\f", `\f`,
+	"\r", `\r`,
+	"\x0e", `\u000e`,
+	"\x0f", `\u000f`,
+	"\x10", `\u0010`,
+	"\x11", `\u0011`,
+	"\x12", `\u0012`,
+	"\x13", `\u0013`,
+	"\x14", `\u0014`,
+	"\x15", `\u0015`,
+	"\x16", `\u0016`,
+	"\x17", `\u0017`,
+	"\x18", `\u0018`,
+	"\x19", `\u0019`,
+	"\x1a", `\u001a`,
+	"\x1b", `\u001b`,
+	"\x1c", `\u001c`,
+	"\x1d", `\u001d`,
+	"\x1e", `\u001e`,
+	"\x1f", `\u001f`,
+	"\x7f", `\u007f`,
+)
+
+var (
+	marshalToml = reflect.TypeOf((*Marshaler)(nil)).Elem()
+	marshalText = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem()
+	timeType    = reflect.TypeOf((*time.Time)(nil)).Elem()
+)
+
+// Marshaler is the interface implemented by types that can marshal themselves
+// into valid TOML.
+type Marshaler interface {
+	MarshalTOML() ([]byte, error)
+}
+
+// Encoder encodes a Go to a TOML document.
+//
+// The mapping between Go values and TOML values should be precisely the same as
+// for [Decode].
+//
+// time.Time is encoded as a RFC 3339 string, and time.Duration as its string
+// representation.
+//
+// The [Marshaler] and [encoding.TextMarshaler] interfaces are supported to
+// encoding the value as custom TOML.
+//
+// If you want to write arbitrary binary data then you will need to use
+// something like base64 since TOML does not have any binary types.
+//
+// When encoding TOML hashes (Go maps or structs), keys without any sub-hashes
+// are encoded first.
+//
+// Go maps will be sorted alphabetically by key for deterministic output.
+//
+// The toml struct tag can be used to provide the key name; if omitted the
+// struct field name will be used. If the "omitempty" option is present the
+// following value will be skipped:
+//
+//   - arrays, slices, maps, and string with len of 0
+//   - struct with all zero values
+//   - bool false
+//
+// If omitzero is given all int and float types with a value of 0 will be
+// skipped.
+//
+// Encoding Go values without a corresponding TOML representation will return an
+// error. Examples of this includes maps with non-string keys, slices with nil
+// elements, embedded non-struct types, and nested slices containing maps or
+// structs. (e.g. [][]map[string]string is not allowed but []map[string]string
+// is okay, as is []map[string][]string).
+//
+// NOTE: only exported keys are encoded due to the use of reflection. Unexported
+// keys are silently discarded.
+type Encoder struct {
+	// String to use for a single indentation level; default is two spaces.
+	Indent string
+
+	w          *bufio.Writer
+	hasWritten bool // written any output to w yet?
+}
+
+// NewEncoder create a new Encoder.
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{
+		w:      bufio.NewWriter(w),
+		Indent: "  ",
+	}
+}
+
+// Encode writes a TOML representation of the Go value to the [Encoder]'s writer.
+//
+// An error is returned if the value given cannot be encoded to a valid TOML
+// document.
+func (enc *Encoder) Encode(v interface{}) error {
+	rv := eindirect(reflect.ValueOf(v))
+	if err := enc.safeEncode(Key([]string{}), rv); err != nil {
+		return err
+	}
+	return enc.w.Flush()
+}
+
+func (enc *Encoder) safeEncode(key Key, rv reflect.Value) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			if terr, ok := r.(tomlEncodeError); ok {
+				err = terr.error
+				return
+			}
+			panic(r)
+		}
+	}()
+	enc.encode(key, rv)
+	return nil
+}
+
+func (enc *Encoder) encode(key Key, rv reflect.Value) {
+	// If we can marshal the type to text, then we use that. This prevents the
+	// encoder for handling these types as generic structs (or whatever the
+	// underlying type of a TextMarshaler is).
+	switch {
+	case isMarshaler(rv):
+		enc.writeKeyValue(key, rv, false)
+		return
+	case rv.Type() == primitiveType: // TODO: #76 would make this superfluous after implemented.
+		enc.encode(key, reflect.ValueOf(rv.Interface().(Primitive).undecoded))
+		return
+	}
+
+	k := rv.Kind()
+	switch k {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32,
+		reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32,
+		reflect.Uint64,
+		reflect.Float32, reflect.Float64, reflect.String, reflect.Bool:
+		enc.writeKeyValue(key, rv, false)
+	case reflect.Array, reflect.Slice:
+		if typeEqual(tomlArrayHash, tomlTypeOfGo(rv)) {
+			enc.eArrayOfTables(key, rv)
+		} else {
+			enc.writeKeyValue(key, rv, false)
+		}
+	case reflect.Interface:
+		if rv.IsNil() {
+			return
+		}
+		enc.encode(key, rv.Elem())
+	case reflect.Map:
+		if rv.IsNil() {
+			return
+		}
+		enc.eTable(key, rv)
+	case reflect.Ptr:
+		if rv.IsNil() {
+			return
+		}
+		enc.encode(key, rv.Elem())
+	case reflect.Struct:
+		enc.eTable(key, rv)
+	default:
+		encPanic(fmt.Errorf("unsupported type for key '%s': %s", key, k))
+	}
+}
+
+// eElement encodes any value that can be an array element.
+func (enc *Encoder) eElement(rv reflect.Value) {
+	switch v := rv.Interface().(type) {
+	case time.Time: // Using TextMarshaler adds extra quotes, which we don't want.
+		format := time.RFC3339Nano
+		switch v.Location() {
+		case internal.LocalDatetime:
+			format = "2006-01-02T15:04:05.999999999"
+		case internal.LocalDate:
+			format = "2006-01-02"
+		case internal.LocalTime:
+			format = "15:04:05.999999999"
+		}
+		switch v.Location() {
+		default:
+			enc.wf(v.Format(format))
+		case internal.LocalDatetime, internal.LocalDate, internal.LocalTime:
+			enc.wf(v.In(time.UTC).Format(format))
+		}
+		return
+	case Marshaler:
+		s, err := v.MarshalTOML()
+		if err != nil {
+			encPanic(err)
+		}
+		if s == nil {
+			encPanic(errors.New("MarshalTOML returned nil and no error"))
+		}
+		enc.w.Write(s)
+		return
+	case encoding.TextMarshaler:
+		s, err := v.MarshalText()
+		if err != nil {
+			encPanic(err)
+		}
+		if s == nil {
+			encPanic(errors.New("MarshalText returned nil and no error"))
+		}
+		enc.writeQuoted(string(s))
+		return
+	case time.Duration:
+		enc.writeQuoted(v.String())
+		return
+	case json.Number:
+		n, _ := rv.Interface().(json.Number)
+
+		if n == "" { /// Useful zero value.
+			enc.w.WriteByte('0')
+			return
+		} else if v, err := n.Int64(); err == nil {
+			enc.eElement(reflect.ValueOf(v))
+			return
+		} else if v, err := n.Float64(); err == nil {
+			enc.eElement(reflect.ValueOf(v))
+			return
+		}
+		encPanic(fmt.Errorf("unable to convert %q to int64 or float64", n))
+	}
+
+	switch rv.Kind() {
+	case reflect.Ptr:
+		enc.eElement(rv.Elem())
+		return
+	case reflect.String:
+		enc.writeQuoted(rv.String())
+	case reflect.Bool:
+		enc.wf(strconv.FormatBool(rv.Bool()))
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		enc.wf(strconv.FormatInt(rv.Int(), 10))
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		enc.wf(strconv.FormatUint(rv.Uint(), 10))
+	case reflect.Float32:
+		f := rv.Float()
+		if math.IsNaN(f) {
+			enc.wf("nan")
+		} else if math.IsInf(f, 0) {
+			enc.wf("%cinf", map[bool]byte{true: '-', false: '+'}[math.Signbit(f)])
+		} else {
+			enc.wf(floatAddDecimal(strconv.FormatFloat(f, 'f', -1, 32)))
+		}
+	case reflect.Float64:
+		f := rv.Float()
+		if math.IsNaN(f) {
+			enc.wf("nan")
+		} else if math.IsInf(f, 0) {
+			enc.wf("%cinf", map[bool]byte{true: '-', false: '+'}[math.Signbit(f)])
+		} else {
+			enc.wf(floatAddDecimal(strconv.FormatFloat(f, 'f', -1, 64)))
+		}
+	case reflect.Array, reflect.Slice:
+		enc.eArrayOrSliceElement(rv)
+	case reflect.Struct:
+		enc.eStruct(nil, rv, true)
+	case reflect.Map:
+		enc.eMap(nil, rv, true)
+	case reflect.Interface:
+		enc.eElement(rv.Elem())
+	default:
+		encPanic(fmt.Errorf("unexpected type: %T", rv.Interface()))
+	}
+}
+
+// By the TOML spec, all floats must have a decimal with at least one number on
+// either side.
+func floatAddDecimal(fstr string) string {
+	if !strings.Contains(fstr, ".") {
+		return fstr + ".0"
+	}
+	return fstr
+}
+
+func (enc *Encoder) writeQuoted(s string) {
+	enc.wf("\"%s\"", dblQuotedReplacer.Replace(s))
+}
+
+func (enc *Encoder) eArrayOrSliceElement(rv reflect.Value) {
+	length := rv.Len()
+	enc.wf("[")
+	for i := 0; i < length; i++ {
+		elem := eindirect(rv.Index(i))
+		enc.eElement(elem)
+		if i != length-1 {
+			enc.wf(", ")
+		}
+	}
+	enc.wf("]")
+}
+
+func (enc *Encoder) eArrayOfTables(key Key, rv reflect.Value) {
+	if len(key) == 0 {
+		encPanic(errNoKey)
+	}
+	for i := 0; i < rv.Len(); i++ {
+		trv := eindirect(rv.Index(i))
+		if isNil(trv) {
+			continue
+		}
+		enc.newline()
+		enc.wf("%s[[%s]]", enc.indentStr(key), key)
+		enc.newline()
+		enc.eMapOrStruct(key, trv, false)
+	}
+}
+
+func (enc *Encoder) eTable(key Key, rv reflect.Value) {
+	if len(key) == 1 {
+		// Output an extra newline between top-level tables.
+		// (The newline isn't written if nothing else has been written though.)
+		enc.newline()
+	}
+	if len(key) > 0 {
+		enc.wf("%s[%s]", enc.indentStr(key), key)
+		enc.newline()
+	}
+	enc.eMapOrStruct(key, rv, false)
+}
+
+func (enc *Encoder) eMapOrStruct(key Key, rv reflect.Value, inline bool) {
+	switch rv.Kind() {
+	case reflect.Map:
+		enc.eMap(key, rv, inline)
+	case reflect.Struct:
+		enc.eStruct(key, rv, inline)
+	default:
+		// Should never happen?
+		panic("eTable: unhandled reflect.Value Kind: " + rv.Kind().String())
+	}
+}
+
+func (enc *Encoder) eMap(key Key, rv reflect.Value, inline bool) {
+	rt := rv.Type()
+	if rt.Key().Kind() != reflect.String {
+		encPanic(errNonString)
+	}
+
+	// Sort keys so that we have deterministic output. And write keys directly
+	// underneath this key first, before writing sub-structs or sub-maps.
+	var mapKeysDirect, mapKeysSub []string
+	for _, mapKey := range rv.MapKeys() {
+		k := mapKey.String()
+		if typeIsTable(tomlTypeOfGo(eindirect(rv.MapIndex(mapKey)))) {
+			mapKeysSub = append(mapKeysSub, k)
+		} else {
+			mapKeysDirect = append(mapKeysDirect, k)
+		}
+	}
+
+	var writeMapKeys = func(mapKeys []string, trailC bool) {
+		sort.Strings(mapKeys)
+		for i, mapKey := range mapKeys {
+			val := eindirect(rv.MapIndex(reflect.ValueOf(mapKey)))
+			if isNil(val) {
+				continue
+			}
+
+			if inline {
+				enc.writeKeyValue(Key{mapKey}, val, true)
+				if trailC || i != len(mapKeys)-1 {
+					enc.wf(", ")
+				}
+			} else {
+				enc.encode(key.add(mapKey), val)
+			}
+		}
+	}
+
+	if inline {
+		enc.wf("{")
+	}
+	writeMapKeys(mapKeysDirect, len(mapKeysSub) > 0)
+	writeMapKeys(mapKeysSub, false)
+	if inline {
+		enc.wf("}")
+	}
+}
+
+const is32Bit = (32 << (^uint(0) >> 63)) == 32
+
+func pointerTo(t reflect.Type) reflect.Type {
+	if t.Kind() == reflect.Ptr {
+		return pointerTo(t.Elem())
+	}
+	return t
+}
+
+func (enc *Encoder) eStruct(key Key, rv reflect.Value, inline bool) {
+	// Write keys for fields directly under this key first, because if we write
+	// a field that creates a new table then all keys under it will be in that
+	// table (not the one we're writing here).
+	//
+	// Fields is a [][]int: for fieldsDirect this always has one entry (the
+	// struct index). For fieldsSub it contains two entries: the parent field
+	// index from tv, and the field indexes for the fields of the sub.
+	var (
+		rt                      = rv.Type()
+		fieldsDirect, fieldsSub [][]int
+		addFields               func(rt reflect.Type, rv reflect.Value, start []int)
+	)
+	addFields = func(rt reflect.Type, rv reflect.Value, start []int) {
+		for i := 0; i < rt.NumField(); i++ {
+			f := rt.Field(i)
+			isEmbed := f.Anonymous && pointerTo(f.Type).Kind() == reflect.Struct
+			if f.PkgPath != "" && !isEmbed { /// Skip unexported fields.
+				continue
+			}
+			opts := getOptions(f.Tag)
+			if opts.skip {
+				continue
+			}
+
+			frv := eindirect(rv.Field(i))
+
+			// Treat anonymous struct fields with tag names as though they are
+			// not anonymous, like encoding/json does.
+			//
+			// Non-struct anonymous fields use the normal encoding logic.
+			if isEmbed {
+				if getOptions(f.Tag).name == "" && frv.Kind() == reflect.Struct {
+					addFields(frv.Type(), frv, append(start, f.Index...))
+					continue
+				}
+			}
+
+			if typeIsTable(tomlTypeOfGo(frv)) {
+				fieldsSub = append(fieldsSub, append(start, f.Index...))
+			} else {
+				// Copy so it works correct on 32bit archs; not clear why this
+				// is needed. See #314, and https://www.reddit.com/r/golang/comments/pnx8v4
+				// This also works fine on 64bit, but 32bit archs are somewhat
+				// rare and this is a wee bit faster.
+				if is32Bit {
+					copyStart := make([]int, len(start))
+					copy(copyStart, start)
+					fieldsDirect = append(fieldsDirect, append(copyStart, f.Index...))
+				} else {
+					fieldsDirect = append(fieldsDirect, append(start, f.Index...))
+				}
+			}
+		}
+	}
+	addFields(rt, rv, nil)
+
+	writeFields := func(fields [][]int) {
+		for _, fieldIndex := range fields {
+			fieldType := rt.FieldByIndex(fieldIndex)
+			fieldVal := eindirect(rv.FieldByIndex(fieldIndex))
+
+			if isNil(fieldVal) { /// Don't write anything for nil fields.
+				continue
+			}
+
+			opts := getOptions(fieldType.Tag)
+			if opts.skip {
+				continue
+			}
+			keyName := fieldType.Name
+			if opts.name != "" {
+				keyName = opts.name
+			}
+
+			if opts.omitempty && enc.isEmpty(fieldVal) {
+				continue
+			}
+			if opts.omitzero && isZero(fieldVal) {
+				continue
+			}
+
+			if inline {
+				enc.writeKeyValue(Key{keyName}, fieldVal, true)
+				if fieldIndex[0] != len(fields)-1 {
+					enc.wf(", ")
+				}
+			} else {
+				enc.encode(key.add(keyName), fieldVal)
+			}
+		}
+	}
+
+	if inline {
+		enc.wf("{")
+	}
+	writeFields(fieldsDirect)
+	writeFields(fieldsSub)
+	if inline {
+		enc.wf("}")
+	}
+}
+
+// tomlTypeOfGo returns the TOML type name of the Go value's type.
+//
+// It is used to determine whether the types of array elements are mixed (which
+// is forbidden). If the Go value is nil, then it is illegal for it to be an
+// array element, and valueIsNil is returned as true.
+//
+// The type may be `nil`, which means no concrete TOML type could be found.
+func tomlTypeOfGo(rv reflect.Value) tomlType {
+	if isNil(rv) || !rv.IsValid() {
+		return nil
+	}
+
+	if rv.Kind() == reflect.Struct {
+		if rv.Type() == timeType {
+			return tomlDatetime
+		}
+		if isMarshaler(rv) {
+			return tomlString
+		}
+		return tomlHash
+	}
+
+	if isMarshaler(rv) {
+		return tomlString
+	}
+
+	switch rv.Kind() {
+	case reflect.Bool:
+		return tomlBool
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32,
+		reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32,
+		reflect.Uint64:
+		return tomlInteger
+	case reflect.Float32, reflect.Float64:
+		return tomlFloat
+	case reflect.Array, reflect.Slice:
+		if isTableArray(rv) {
+			return tomlArrayHash
+		}
+		return tomlArray
+	case reflect.Ptr, reflect.Interface:
+		return tomlTypeOfGo(rv.Elem())
+	case reflect.String:
+		return tomlString
+	case reflect.Map:
+		return tomlHash
+	default:
+		encPanic(errors.New("unsupported type: " + rv.Kind().String()))
+		panic("unreachable")
+	}
+}
+
+func isMarshaler(rv reflect.Value) bool {
+	return rv.Type().Implements(marshalText) || rv.Type().Implements(marshalToml)
+}
+
+// isTableArray reports if all entries in the array or slice are a table.
+func isTableArray(arr reflect.Value) bool {
+	if isNil(arr) || !arr.IsValid() || arr.Len() == 0 {
+		return false
+	}
+
+	ret := true
+	for i := 0; i < arr.Len(); i++ {
+		tt := tomlTypeOfGo(eindirect(arr.Index(i)))
+		// Don't allow nil.
+		if tt == nil {
+			encPanic(errArrayNilElement)
+		}
+
+		if ret && !typeEqual(tomlHash, tt) {
+			ret = false
+		}
+	}
+	return ret
+}
+
+type tagOptions struct {
+	skip      bool // "-"
+	name      string
+	omitempty bool
+	omitzero  bool
+}
+
+func getOptions(tag reflect.StructTag) tagOptions {
+	t := tag.Get("toml")
+	if t == "-" {
+		return tagOptions{skip: true}
+	}
+	var opts tagOptions
+	parts := strings.Split(t, ",")
+	opts.name = parts[0]
+	for _, s := range parts[1:] {
+		switch s {
+		case "omitempty":
+			opts.omitempty = true
+		case "omitzero":
+			opts.omitzero = true
+		}
+	}
+	return opts
+}
+
+func isZero(rv reflect.Value) bool {
+	switch rv.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return rv.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		return rv.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return rv.Float() == 0.0
+	}
+	return false
+}
+
+func (enc *Encoder) isEmpty(rv reflect.Value) bool {
+	switch rv.Kind() {
+	case reflect.Array, reflect.Slice, reflect.Map, reflect.String:
+		return rv.Len() == 0
+	case reflect.Struct:
+		if rv.Type().Comparable() {
+			return reflect.Zero(rv.Type()).Interface() == rv.Interface()
+		}
+		// Need to also check if all the fields are empty, otherwise something
+		// like this with uncomparable types will always return true:
+		//
+		//   type a struct{ field b }
+		//   type b struct{ s []string }
+		//   s := a{field: b{s: []string{"AAA"}}}
+		for i := 0; i < rv.NumField(); i++ {
+			if !enc.isEmpty(rv.Field(i)) {
+				return false
+			}
+		}
+		return true
+	case reflect.Bool:
+		return !rv.Bool()
+	}
+	return false
+}
+
+func (enc *Encoder) newline() {
+	if enc.hasWritten {
+		enc.wf("\n")
+	}
+}
+
+// Write a key/value pair:
+//
+//	key = <any value>
+//
+// This is also used for "k = v" in inline tables; so something like this will
+// be written in three calls:
+//
+//	┌───────────────────┐
+//	│      ┌───┐  ┌────┐│
+//	v      v   v  v    vv
+//	key = {k = 1, k2 = 2}
+func (enc *Encoder) writeKeyValue(key Key, val reflect.Value, inline bool) {
+	if len(key) == 0 {
+		encPanic(errNoKey)
+	}
+	enc.wf("%s%s = ", enc.indentStr(key), key.maybeQuoted(len(key)-1))
+	enc.eElement(val)
+	if !inline {
+		enc.newline()
+	}
+}
+
+func (enc *Encoder) wf(format string, v ...interface{}) {
+	_, err := fmt.Fprintf(enc.w, format, v...)
+	if err != nil {
+		encPanic(err)
+	}
+	enc.hasWritten = true
+}
+
+func (enc *Encoder) indentStr(key Key) string {
+	return strings.Repeat(enc.Indent, len(key)-1)
+}
+
+func encPanic(err error) {
+	panic(tomlEncodeError{err})
+}
+
+// Resolve any level of pointers to the actual value (e.g. **string → string).
+func eindirect(v reflect.Value) reflect.Value {
+	if v.Kind() != reflect.Ptr && v.Kind() != reflect.Interface {
+		if isMarshaler(v) {
+			return v
+		}
+		if v.CanAddr() { /// Special case for marshalers; see #358.
+			if pv := v.Addr(); isMarshaler(pv) {
+				return pv
+			}
+		}
+		return v
+	}
+
+	if v.IsNil() {
+		return v
+	}
+
+	return eindirect(v.Elem())
+}
+
+func isNil(rv reflect.Value) bool {
+	switch rv.Kind() {
+	case reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
+		return rv.IsNil()
+	default:
+		return false
+	}
+}

vendor/github.com/BurntSushi/toml/error.go

@@ -0,0 +1,279 @@
+package toml
+
+import (
+	"fmt"
+	"strings"
+)
+
+// ParseError is returned when there is an error parsing the TOML syntax such as
+// invalid syntax, duplicate keys, etc.
+//
+// In addition to the error message itself, you can also print detailed location
+// information with context by using [ErrorWithPosition]:
+//
+//	toml: error: Key 'fruit' was already created and cannot be used as an array.
+//
+//	At line 4, column 2-7:
+//
+//	      2 | fruit = []
+//	      3 |
+//	      4 | [[fruit]] # Not allowed
+//	            ^^^^^
+//
+// [ErrorWithUsage] can be used to print the above with some more detailed usage
+// guidance:
+//
+//	toml: error: newlines not allowed within inline tables
+//
+//	At line 1, column 18:
+//
+//	      1 | x = [{ key = 42 #
+//	                           ^
+//
+//	Error help:
+//
+//	  Inline tables must always be on a single line:
+//
+//	      table = {key = 42, second = 43}
+//
+//	  It is invalid to split them over multiple lines like so:
+//
+//	      # INVALID
+//	      table = {
+//	          key    = 42,
+//	          second = 43
+//	      }
+//
+//	  Use regular for this:
+//
+//	      [table]
+//	      key    = 42
+//	      second = 43
+type ParseError struct {
+	Message  string   // Short technical message.
+	Usage    string   // Longer message with usage guidance; may be blank.
+	Position Position // Position of the error
+	LastKey  string   // Last parsed key, may be blank.
+
+	// Line the error occurred.
+	//
+	// Deprecated: use [Position].
+	Line int
+
+	err   error
+	input string
+}
+
+// Position of an error.
+type Position struct {
+	Line  int // Line number, starting at 1.
+	Start int // Start of error, as byte offset starting at 0.
+	Len   int // Lenght in bytes.
+}
+
+func (pe ParseError) Error() string {
+	msg := pe.Message
+	if msg == "" { // Error from errorf()
+		msg = pe.err.Error()
+	}
+
+	if pe.LastKey == "" {
+		return fmt.Sprintf("toml: line %d: %s", pe.Position.Line, msg)
+	}
+	return fmt.Sprintf("toml: line %d (last key %q): %s",
+		pe.Position.Line, pe.LastKey, msg)
+}
+
+// ErrorWithUsage() returns the error with detailed location context.
+//
+// See the documentation on [ParseError].
+func (pe ParseError) ErrorWithPosition() string {
+	if pe.input == "" { // Should never happen, but just in case.
+		return pe.Error()
+	}
+
+	var (
+		lines = strings.Split(pe.input, "\n")
+		col   = pe.column(lines)
+		b     = new(strings.Builder)
+	)
+
+	msg := pe.Message
+	if msg == "" {
+		msg = pe.err.Error()
+	}
+
+	// TODO: don't show control characters as literals? This may not show up
+	// well everywhere.
+
+	if pe.Position.Len == 1 {
+		fmt.Fprintf(b, "toml: error: %s\n\nAt line %d, column %d:\n\n",
+			msg, pe.Position.Line, col+1)
+	} else {
+		fmt.Fprintf(b, "toml: error: %s\n\nAt line %d, column %d-%d:\n\n",
+			msg, pe.Position.Line, col, col+pe.Position.Len)
+	}
+	if pe.Position.Line > 2 {
+		fmt.Fprintf(b, "% 7d | %s\n", pe.Position.Line-2, lines[pe.Position.Line-3])
+	}
+	if pe.Position.Line > 1 {
+		fmt.Fprintf(b, "% 7d | %s\n", pe.Position.Line-1, lines[pe.Position.Line-2])
+	}
+	fmt.Fprintf(b, "% 7d | %s\n", pe.Position.Line, lines[pe.Position.Line-1])
+	fmt.Fprintf(b, "% 10s%s%s\n", "", strings.Repeat(" ", col), strings.Repeat("^", pe.Position.Len))
+	return b.String()
+}
+
+// ErrorWithUsage() returns the error with detailed location context and usage
+// guidance.
+//
+// See the documentation on [ParseError].
+func (pe ParseError) ErrorWithUsage() string {
+	m := pe.ErrorWithPosition()
+	if u, ok := pe.err.(interface{ Usage() string }); ok && u.Usage() != "" {
+		lines := strings.Split(strings.TrimSpace(u.Usage()), "\n")
+		for i := range lines {
+			if lines[i] != "" {
+				lines[i] = "    " + lines[i]
+			}
+		}
+		return m + "Error help:\n\n" + strings.Join(lines, "\n") + "\n"
+	}
+	return m
+}
+
+func (pe ParseError) column(lines []string) int {
+	var pos, col int
+	for i := range lines {
+		ll := len(lines[i]) + 1 // +1 for the removed newline
+		if pos+ll >= pe.Position.Start {
+			col = pe.Position.Start - pos
+			if col < 0 { // Should never happen, but just in case.
+				col = 0
+			}
+			break
+		}
+		pos += ll
+	}
+
+	return col
+}
+
+type (
+	errLexControl       struct{ r rune }
+	errLexEscape        struct{ r rune }
+	errLexUTF8          struct{ b byte }
+	errLexInvalidNum    struct{ v string }
+	errLexInvalidDate   struct{ v string }
+	errLexInlineTableNL struct{}
+	errLexStringNL      struct{}
+	errParseRange       struct {
+		i    interface{} // int or float
+		size string      // "int64", "uint16", etc.
+	}
+	errParseDuration struct{ d string }
+)
+
+func (e errLexControl) Error() string {
+	return fmt.Sprintf("TOML files cannot contain control characters: '0x%02x'", e.r)
+}
+func (e errLexControl) Usage() string { return "" }
+
+func (e errLexEscape) Error() string        { return fmt.Sprintf(`invalid escape in string '\%c'`, e.r) }
+func (e errLexEscape) Usage() string        { return usageEscape }
+func (e errLexUTF8) Error() string          { return fmt.Sprintf("invalid UTF-8 byte: 0x%02x", e.b) }
+func (e errLexUTF8) Usage() string          { return "" }
+func (e errLexInvalidNum) Error() string    { return fmt.Sprintf("invalid number: %q", e.v) }
+func (e errLexInvalidNum) Usage() string    { return "" }
+func (e errLexInvalidDate) Error() string   { return fmt.Sprintf("invalid date: %q", e.v) }
+func (e errLexInvalidDate) Usage() string   { return "" }
+func (e errLexInlineTableNL) Error() string { return "newlines not allowed within inline tables" }
+func (e errLexInlineTableNL) Usage() string { return usageInlineNewline }
+func (e errLexStringNL) Error() string      { return "strings cannot contain newlines" }
+func (e errLexStringNL) Usage() string      { return usageStringNewline }
+func (e errParseRange) Error() string       { return fmt.Sprintf("%v is out of range for %s", e.i, e.size) }
+func (e errParseRange) Usage() string       { return usageIntOverflow }
+func (e errParseDuration) Error() string    { return fmt.Sprintf("invalid duration: %q", e.d) }
+func (e errParseDuration) Usage() string    { return usageDuration }
+
+const usageEscape = `
+A '\' inside a "-delimited string is interpreted as an escape character.
+
+The following escape sequences are supported:
+\b, \t, \n, \f, \r, \", \\, \uXXXX, and \UXXXXXXXX
+
+To prevent a '\' from being recognized as an escape character, use either:
+
+- a ' or '''-delimited string; escape characters aren't processed in them; or
+- write two backslashes to get a single backslash: '\\'.
+
+If you're trying to add a Windows path (e.g. "C:\Users\martin") then using '/'
+instead of '\' will usually also work: "C:/Users/martin".
+`
+
+const usageInlineNewline = `
+Inline tables must always be on a single line:
+
+    table = {key = 42, second = 43}
+
+It is invalid to split them over multiple lines like so:
+
+    # INVALID
+    table = {
+        key    = 42,
+        second = 43
+    }
+
+Use regular for this:
+
+    [table]
+    key    = 42
+    second = 43
+`
+
+const usageStringNewline = `
+Strings must always be on a single line, and cannot span more than one line:
+
+    # INVALID
+    string = "Hello,
+    world!"
+
+Instead use """ or ''' to split strings over multiple lines:
+
+    string = """Hello,
+    world!"""
+`
+
+const usageIntOverflow = `
+This number is too large; this may be an error in the TOML, but it can also be a
+bug in the program that uses too small of an integer.
+
+The maximum and minimum values are:
+
+    size   │ lowest         │ highest
+    ───────┼────────────────┼──────────
+    int8   │ -128           │ 127
+    int16  │ -32,768        │ 32,767
+    int32  │ -2,147,483,648 │ 2,147,483,647
+    int64  │ -9.2 × 10¹⁷    │ 9.2 × 10¹⁷
+    uint8  │ 0              │ 255
+    uint16 │ 0              │ 65535
+    uint32 │ 0              │ 4294967295
+    uint64 │ 0              │ 1.8 × 10¹⁸
+
+int refers to int32 on 32-bit systems and int64 on 64-bit systems.
+`
+
+const usageDuration = `
+A duration must be as "number<unit>", without any spaces. Valid units are:
+
+    ns         nanoseconds (billionth of a second)
+    us, µs     microseconds (millionth of a second)
+    ms         milliseconds (thousands of a second)
+    s          seconds
+    m          minutes
+    h          hours
+
+You can combine multiple units; for example "5m10s" for 5 minutes and 10
+seconds.
+`

vendor/github.com/BurntSushi/toml/internal/tz.go

@@ -0,0 +1,36 @@
+package internal
+
+import "time"
+
+// Timezones used for local datetime, date, and time TOML types.
+//
+// The exact way times and dates without a timezone should be interpreted is not
+// well-defined in the TOML specification and left to the implementation. These
+// defaults to current local timezone offset of the computer, but this can be
+// changed by changing these variables before decoding.
+//
+// TODO:
+// Ideally we'd like to offer people the ability to configure the used timezone
+// by setting Decoder.Timezone and Encoder.Timezone; however, this is a bit
+// tricky: the reason we use three different variables for this is to support
+// round-tripping – without these specific TZ names we wouldn't know which
+// format to use.
+//
+// There isn't a good way to encode this right now though, and passing this sort
+// of information also ties in to various related issues such as string format
+// encoding, encoding of comments, etc.
+//
+// So, for the time being, just put this in internal until we can write a good
+// comprehensive API for doing all of this.
+//
+// The reason they're exported is because they're referred from in e.g.
+// internal/tag.
+//
+// Note that this behaviour is valid according to the TOML spec as the exact
+// behaviour is left up to implementations.
+var (
+	localOffset   = func() int { _, o := time.Now().Zone(); return o }()
+	LocalDatetime = time.FixedZone("datetime-local", localOffset)
+	LocalDate     = time.FixedZone("date-local", localOffset)
+	LocalTime     = time.FixedZone("time-local", localOffset)
+)

vendor/github.com/BurntSushi/toml/meta.go

@@ -0,0 +1,121 @@
+package toml
+
+import (
+	"strings"
+)
+
+// MetaData allows access to meta information about TOML data that's not
+// accessible otherwise.
+//
+// It allows checking if a key is defined in the TOML data, whether any keys
+// were undecoded, and the TOML type of a key.
+type MetaData struct {
+	context Key // Used only during decoding.
+
+	keyInfo map[string]keyInfo
+	mapping map[string]interface{}
+	keys    []Key
+	decoded map[string]struct{}
+	data    []byte // Input file; for errors.
+}
+
+// IsDefined reports if the key exists in the TOML data.
+//
+// The key should be specified hierarchically, for example to access the TOML
+// key "a.b.c" you would use IsDefined("a", "b", "c"). Keys are case sensitive.
+//
+// Returns false for an empty key.
+func (md *MetaData) IsDefined(key ...string) bool {
+	if len(key) == 0 {
+		return false
+	}
+
+	var (
+		hash      map[string]interface{}
+		ok        bool
+		hashOrVal interface{} = md.mapping
+	)
+	for _, k := range key {
+		if hash, ok = hashOrVal.(map[string]interface{}); !ok {
+			return false
+		}
+		if hashOrVal, ok = hash[k]; !ok {
+			return false
+		}
+	}
+	return true
+}
+
+// Type returns a string representation of the type of the key specified.
+//
+// Type will return the empty string if given an empty key or a key that does
+// not exist. Keys are case sensitive.
+func (md *MetaData) Type(key ...string) string {
+	if ki, ok := md.keyInfo[Key(key).String()]; ok {
+		return ki.tomlType.typeString()
+	}
+	return ""
+}
+
+// Keys returns a slice of every key in the TOML data, including key groups.
+//
+// Each key is itself a slice, where the first element is the top of the
+// hierarchy and the last is the most specific. The list will have the same
+// order as the keys appeared in the TOML data.
+//
+// All keys returned are non-empty.
+func (md *MetaData) Keys() []Key {
+	return md.keys
+}
+
+// Undecoded returns all keys that have not been decoded in the order in which
+// they appear in the original TOML document.
+//
+// This includes keys that haven't been decoded because of a [Primitive] value.
+// Once the Primitive value is decoded, the keys will be considered decoded.
+//
+// Also note that decoding into an empty interface will result in no decoding,
+// and so no keys will be considered decoded.
+//
+// In this sense, the Undecoded keys correspond to keys in the TOML document
+// that do not have a concrete type in your representation.
+func (md *MetaData) Undecoded() []Key {
+	undecoded := make([]Key, 0, len(md.keys))
+	for _, key := range md.keys {
+		if _, ok := md.decoded[key.String()]; !ok {
+			undecoded = append(undecoded, key)
+		}
+	}
+	return undecoded
+}
+
+// Key represents any TOML key, including key groups. Use [MetaData.Keys] to get
+// values of this type.
+type Key []string
+
+func (k Key) String() string {
+	ss := make([]string, len(k))
+	for i := range k {
+		ss[i] = k.maybeQuoted(i)
+	}
+	return strings.Join(ss, ".")
+}
+
+func (k Key) maybeQuoted(i int) string {
+	if k[i] == "" {
+		return `""`
+	}
+	for _, c := range k[i] {
+		if !isBareKeyChar(c) {
+			return `"` + dblQuotedReplacer.Replace(k[i]) + `"`
+		}
+	}
+	return k[i]
+}
+
+func (k Key) add(piece string) Key {
+	newKey := make(Key, len(k)+1)
+	copy(newKey, k)
+	newKey[len(k)] = piece
+	return newKey
+}

vendor/github.com/BurntSushi/toml/parse.go

@@ -0,0 +1,781 @@
+package toml
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+	"unicode/utf8"
+
+	"github.com/BurntSushi/toml/internal"
+)
+
+type parser struct {
+	lx         *lexer
+	context    Key      // Full key for the current hash in scope.
+	currentKey string   // Base key name for everything except hashes.
+	pos        Position // Current position in the TOML file.
+
+	ordered []Key // List of keys in the order that they appear in the TOML data.
+
+	keyInfo   map[string]keyInfo     // Map keyname → info about the TOML key.
+	mapping   map[string]interface{} // Map keyname → key value.
+	implicits map[string]struct{}    // Record implicit keys (e.g. "key.group.names").
+}
+
+type keyInfo struct {
+	pos      Position
+	tomlType tomlType
+}
+
+func parse(data string) (p *parser, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			if pErr, ok := r.(ParseError); ok {
+				pErr.input = data
+				err = pErr
+				return
+			}
+			panic(r)
+		}
+	}()
+
+	// Read over BOM; do this here as the lexer calls utf8.DecodeRuneInString()
+	// which mangles stuff.
+	if strings.HasPrefix(data, "\xff\xfe") || strings.HasPrefix(data, "\xfe\xff") {
+		data = data[2:]
+	}
+
+	// Examine first few bytes for NULL bytes; this probably means it's a UTF-16
+	// file (second byte in surrogate pair being NULL). Again, do this here to
+	// avoid having to deal with UTF-8/16 stuff in the lexer.
+	ex := 6
+	if len(data) < 6 {
+		ex = len(data)
+	}
+	if i := strings.IndexRune(data[:ex], 0); i > -1 {
+		return nil, ParseError{
+			Message:  "files cannot contain NULL bytes; probably using UTF-16; TOML files must be UTF-8",
+			Position: Position{Line: 1, Start: i, Len: 1},
+			Line:     1,
+			input:    data,
+		}
+	}
+
+	p = &parser{
+		keyInfo:   make(map[string]keyInfo),
+		mapping:   make(map[string]interface{}),
+		lx:        lex(data),
+		ordered:   make([]Key, 0),
+		implicits: make(map[string]struct{}),
+	}
+	for {
+		item := p.next()
+		if item.typ == itemEOF {
+			break
+		}
+		p.topLevel(item)
+	}
+
+	return p, nil
+}
+
+func (p *parser) panicErr(it item, err error) {
+	panic(ParseError{
+		err:      err,
+		Position: it.pos,
+		Line:     it.pos.Len,
+		LastKey:  p.current(),
+	})
+}
+
+func (p *parser) panicItemf(it item, format string, v ...interface{}) {
+	panic(ParseError{
+		Message:  fmt.Sprintf(format, v...),
+		Position: it.pos,
+		Line:     it.pos.Len,
+		LastKey:  p.current(),
+	})
+}
+
+func (p *parser) panicf(format string, v ...interface{}) {
+	panic(ParseError{
+		Message:  fmt.Sprintf(format, v...),
+		Position: p.pos,
+		Line:     p.pos.Line,
+		LastKey:  p.current(),
+	})
+}
+
+func (p *parser) next() item {
+	it := p.lx.nextItem()
+	//fmt.Printf("ITEM %-18s line %-3d │ %q\n", it.typ, it.pos.Line, it.val)
+	if it.typ == itemError {
+		if it.err != nil {
+			panic(ParseError{
+				Position: it.pos,
+				Line:     it.pos.Line,
+				LastKey:  p.current(),
+				err:      it.err,
+			})
+		}
+
+		p.panicItemf(it, "%s", it.val)
+	}
+	return it
+}
+
+func (p *parser) nextPos() item {
+	it := p.next()
+	p.pos = it.pos
+	return it
+}
+
+func (p *parser) bug(format string, v ...interface{}) {
+	panic(fmt.Sprintf("BUG: "+format+"\n\n", v...))
+}
+
+func (p *parser) expect(typ itemType) item {
+	it := p.next()
+	p.assertEqual(typ, it.typ)
+	return it
+}
+
+func (p *parser) assertEqual(expected, got itemType) {
+	if expected != got {
+		p.bug("Expected '%s' but got '%s'.", expected, got)
+	}
+}
+
+func (p *parser) topLevel(item item) {
+	switch item.typ {
+	case itemCommentStart: // # ..
+		p.expect(itemText)
+	case itemTableStart: // [ .. ]
+		name := p.nextPos()
+
+		var key Key
+		for ; name.typ != itemTableEnd && name.typ != itemEOF; name = p.next() {
+			key = append(key, p.keyString(name))
+		}
+		p.assertEqual(itemTableEnd, name.typ)
+
+		p.addContext(key, false)
+		p.setType("", tomlHash, item.pos)
+		p.ordered = append(p.ordered, key)
+	case itemArrayTableStart: // [[ .. ]]
+		name := p.nextPos()
+
+		var key Key
+		for ; name.typ != itemArrayTableEnd && name.typ != itemEOF; name = p.next() {
+			key = append(key, p.keyString(name))
+		}
+		p.assertEqual(itemArrayTableEnd, name.typ)
+
+		p.addContext(key, true)
+		p.setType("", tomlArrayHash, item.pos)
+		p.ordered = append(p.ordered, key)
+	case itemKeyStart: // key = ..
+		outerContext := p.context
+		/// Read all the key parts (e.g. 'a' and 'b' in 'a.b')
+		k := p.nextPos()
+		var key Key
+		for ; k.typ != itemKeyEnd && k.typ != itemEOF; k = p.next() {
+			key = append(key, p.keyString(k))
+		}
+		p.assertEqual(itemKeyEnd, k.typ)
+
+		/// The current key is the last part.
+		p.currentKey = key[len(key)-1]
+
+		/// All the other parts (if any) are the context; need to set each part
+		/// as implicit.
+		context := key[:len(key)-1]
+		for i := range context {
+			p.addImplicitContext(append(p.context, context[i:i+1]...))
+		}
+
+		/// Set value.
+		vItem := p.next()
+		val, typ := p.value(vItem, false)
+		p.set(p.currentKey, val, typ, vItem.pos)
+		p.ordered = append(p.ordered, p.context.add(p.currentKey))
+
+		/// Remove the context we added (preserving any context from [tbl] lines).
+		p.context = outerContext
+		p.currentKey = ""
+	default:
+		p.bug("Unexpected type at top level: %s", item.typ)
+	}
+}
+
+// Gets a string for a key (or part of a key in a table name).
+func (p *parser) keyString(it item) string {
+	switch it.typ {
+	case itemText:
+		return it.val
+	case itemString, itemMultilineString,
+		itemRawString, itemRawMultilineString:
+		s, _ := p.value(it, false)
+		return s.(string)
+	default:
+		p.bug("Unexpected key type: %s", it.typ)
+	}
+	panic("unreachable")
+}
+
+var datetimeRepl = strings.NewReplacer(
+	"z", "Z",
+	"t", "T",
+	" ", "T")
+
+// value translates an expected value from the lexer into a Go value wrapped
+// as an empty interface.
+func (p *parser) value(it item, parentIsArray bool) (interface{}, tomlType) {
+	switch it.typ {
+	case itemString:
+		return p.replaceEscapes(it, it.val), p.typeOfPrimitive(it)
+	case itemMultilineString:
+		return p.replaceEscapes(it, stripFirstNewline(p.stripEscapedNewlines(it.val))), p.typeOfPrimitive(it)
+	case itemRawString:
+		return it.val, p.typeOfPrimitive(it)
+	case itemRawMultilineString:
+		return stripFirstNewline(it.val), p.typeOfPrimitive(it)
+	case itemInteger:
+		return p.valueInteger(it)
+	case itemFloat:
+		return p.valueFloat(it)
+	case itemBool:
+		switch it.val {
+		case "true":
+			return true, p.typeOfPrimitive(it)
+		case "false":
+			return false, p.typeOfPrimitive(it)
+		default:
+			p.bug("Expected boolean value, but got '%s'.", it.val)
+		}
+	case itemDatetime:
+		return p.valueDatetime(it)
+	case itemArray:
+		return p.valueArray(it)
+	case itemInlineTableStart:
+		return p.valueInlineTable(it, parentIsArray)
+	default:
+		p.bug("Unexpected value type: %s", it.typ)
+	}
+	panic("unreachable")
+}
+
+func (p *parser) valueInteger(it item) (interface{}, tomlType) {
+	if !numUnderscoresOK(it.val) {
+		p.panicItemf(it, "Invalid integer %q: underscores must be surrounded by digits", it.val)
+	}
+	if numHasLeadingZero(it.val) {
+		p.panicItemf(it, "Invalid integer %q: cannot have leading zeroes", it.val)
+	}
+
+	num, err := strconv.ParseInt(it.val, 0, 64)
+	if err != nil {
+		// Distinguish integer values. Normally, it'd be a bug if the lexer
+		// provides an invalid integer, but it's possible that the number is
+		// out of range of valid values (which the lexer cannot determine).
+		// So mark the former as a bug but the latter as a legitimate user
+		// error.
+		if e, ok := err.(*strconv.NumError); ok && e.Err == strconv.ErrRange {
+			p.panicErr(it, errParseRange{i: it.val, size: "int64"})
+		} else {
+			p.bug("Expected integer value, but got '%s'.", it.val)
+		}
+	}
+	return num, p.typeOfPrimitive(it)
+}
+
+func (p *parser) valueFloat(it item) (interface{}, tomlType) {
+	parts := strings.FieldsFunc(it.val, func(r rune) bool {
+		switch r {
+		case '.', 'e', 'E':
+			return true
+		}
+		return false
+	})
+	for _, part := range parts {
+		if !numUnderscoresOK(part) {
+			p.panicItemf(it, "Invalid float %q: underscores must be surrounded by digits", it.val)
+		}
+	}
+	if len(parts) > 0 && numHasLeadingZero(parts[0]) {
+		p.panicItemf(it, "Invalid float %q: cannot have leading zeroes", it.val)
+	}
+	if !numPeriodsOK(it.val) {
+		// As a special case, numbers like '123.' or '1.e2',
+		// which are valid as far as Go/strconv are concerned,
+		// must be rejected because TOML says that a fractional
+		// part consists of '.' followed by 1+ digits.
+		p.panicItemf(it, "Invalid float %q: '.' must be followed by one or more digits", it.val)
+	}
+	val := strings.Replace(it.val, "_", "", -1)
+	if val == "+nan" || val == "-nan" { // Go doesn't support this, but TOML spec does.
+		val = "nan"
+	}
+	num, err := strconv.ParseFloat(val, 64)
+	if err != nil {
+		if e, ok := err.(*strconv.NumError); ok && e.Err == strconv.ErrRange {
+			p.panicErr(it, errParseRange{i: it.val, size: "float64"})
+		} else {
+			p.panicItemf(it, "Invalid float value: %q", it.val)
+		}
+	}
+	return num, p.typeOfPrimitive(it)
+}
+
+var dtTypes = []struct {
+	fmt  string
+	zone *time.Location
+}{
+	{time.RFC3339Nano, time.Local},
+	{"2006-01-02T15:04:05.999999999", internal.LocalDatetime},
+	{"2006-01-02", internal.LocalDate},
+	{"15:04:05.999999999", internal.LocalTime},
+}
+
+func (p *parser) valueDatetime(it item) (interface{}, tomlType) {
+	it.val = datetimeRepl.Replace(it.val)
+	var (
+		t   time.Time
+		ok  bool
+		err error
+	)
+	for _, dt := range dtTypes {
+		t, err = time.ParseInLocation(dt.fmt, it.val, dt.zone)
+		if err == nil {
+			ok = true
+			break
+		}
+	}
+	if !ok {
+		p.panicItemf(it, "Invalid TOML Datetime: %q.", it.val)
+	}
+	return t, p.typeOfPrimitive(it)
+}
+
+func (p *parser) valueArray(it item) (interface{}, tomlType) {
+	p.setType(p.currentKey, tomlArray, it.pos)
+
+	var (
+		types []tomlType
+
+		// Initialize to a non-nil empty slice. This makes it consistent with
+		// how S = [] decodes into a non-nil slice inside something like struct
+		// { S []string }. See #338
+		array = []interface{}{}
+	)
+	for it = p.next(); it.typ != itemArrayEnd; it = p.next() {
+		if it.typ == itemCommentStart {
+			p.expect(itemText)
+			continue
+		}
+
+		val, typ := p.value(it, true)
+		array = append(array, val)
+		types = append(types, typ)
+
+		// XXX: types isn't used here, we need it to record the accurate type
+		// information.
+		//
+		// Not entirely sure how to best store this; could use "key[0]",
+		// "key[1]" notation, or maybe store it on the Array type?
+	}
+	return array, tomlArray
+}
+
+func (p *parser) valueInlineTable(it item, parentIsArray bool) (interface{}, tomlType) {
+	var (
+		hash         = make(map[string]interface{})
+		outerContext = p.context
+		outerKey     = p.currentKey
+	)
+
+	p.context = append(p.context, p.currentKey)
+	prevContext := p.context
+	p.currentKey = ""
+
+	p.addImplicit(p.context)
+	p.addContext(p.context, parentIsArray)
+
+	/// Loop over all table key/value pairs.
+	for it := p.next(); it.typ != itemInlineTableEnd; it = p.next() {
+		if it.typ == itemCommentStart {
+			p.expect(itemText)
+			continue
+		}
+
+		/// Read all key parts.
+		k := p.nextPos()
+		var key Key
+		for ; k.typ != itemKeyEnd && k.typ != itemEOF; k = p.next() {
+			key = append(key, p.keyString(k))
+		}
+		p.assertEqual(itemKeyEnd, k.typ)
+
+		/// The current key is the last part.
+		p.currentKey = key[len(key)-1]
+
+		/// All the other parts (if any) are the context; need to set each part
+		/// as implicit.
+		context := key[:len(key)-1]
+		for i := range context {
+			p.addImplicitContext(append(p.context, context[i:i+1]...))
+		}
+
+		/// Set the value.
+		val, typ := p.value(p.next(), false)
+		p.set(p.currentKey, val, typ, it.pos)
+		p.ordered = append(p.ordered, p.context.add(p.currentKey))
+		hash[p.currentKey] = val
+
+		/// Restore context.
+		p.context = prevContext
+	}
+	p.context = outerContext
+	p.currentKey = outerKey
+	return hash, tomlHash
+}
+
+// numHasLeadingZero checks if this number has leading zeroes, allowing for '0',
+// +/- signs, and base prefixes.
+func numHasLeadingZero(s string) bool {
+	if len(s) > 1 && s[0] == '0' && !(s[1] == 'b' || s[1] == 'o' || s[1] == 'x') { // Allow 0b, 0o, 0x
+		return true
+	}
+	if len(s) > 2 && (s[0] == '-' || s[0] == '+') && s[1] == '0' {
+		return true
+	}
+	return false
+}
+
+// numUnderscoresOK checks whether each underscore in s is surrounded by
+// characters that are not underscores.
+func numUnderscoresOK(s string) bool {
+	switch s {
+	case "nan", "+nan", "-nan", "inf", "-inf", "+inf":
+		return true
+	}
+	accept := false
+	for _, r := range s {
+		if r == '_' {
+			if !accept {
+				return false
+			}
+		}
+
+		// isHexadecimal is a superset of all the permissable characters
+		// surrounding an underscore.
+		accept = isHexadecimal(r)
+	}
+	return accept
+}
+
+// numPeriodsOK checks whether every period in s is followed by a digit.
+func numPeriodsOK(s string) bool {
+	period := false
+	for _, r := range s {
+		if period && !isDigit(r) {
+			return false
+		}
+		period = r == '.'
+	}
+	return !period
+}
+
+// Set the current context of the parser, where the context is either a hash or
+// an array of hashes, depending on the value of the `array` parameter.
+//
+// Establishing the context also makes sure that the key isn't a duplicate, and
+// will create implicit hashes automatically.
+func (p *parser) addContext(key Key, array bool) {
+	var ok bool
+
+	// Always start at the top level and drill down for our context.
+	hashContext := p.mapping
+	keyContext := make(Key, 0)
+
+	// We only need implicit hashes for key[0:-1]
+	for _, k := range key[0 : len(key)-1] {
+		_, ok = hashContext[k]
+		keyContext = append(keyContext, k)
+
+		// No key? Make an implicit hash and move on.
+		if !ok {
+			p.addImplicit(keyContext)
+			hashContext[k] = make(map[string]interface{})
+		}
+
+		// If the hash context is actually an array of tables, then set
+		// the hash context to the last element in that array.
+		//
+		// Otherwise, it better be a table, since this MUST be a key group (by
+		// virtue of it not being the last element in a key).
+		switch t := hashContext[k].(type) {
+		case []map[string]interface{}:
+			hashContext = t[len(t)-1]
+		case map[string]interface{}:
+			hashContext = t
+		default:
+			p.panicf("Key '%s' was already created as a hash.", keyContext)
+		}
+	}
+
+	p.context = keyContext
+	if array {
+		// If this is the first element for this array, then allocate a new
+		// list of tables for it.
+		k := key[len(key)-1]
+		if _, ok := hashContext[k]; !ok {
+			hashContext[k] = make([]map[string]interface{}, 0, 4)
+		}
+
+		// Add a new table. But make sure the key hasn't already been used
+		// for something else.
+		if hash, ok := hashContext[k].([]map[string]interface{}); ok {
+			hashContext[k] = append(hash, make(map[string]interface{}))
+		} else {
+			p.panicf("Key '%s' was already created and cannot be used as an array.", key)
+		}
+	} else {
+		p.setValue(key[len(key)-1], make(map[string]interface{}))
+	}
+	p.context = append(p.context, key[len(key)-1])
+}
+
+// set calls setValue and setType.
+func (p *parser) set(key string, val interface{}, typ tomlType, pos Position) {
+	p.setValue(key, val)
+	p.setType(key, typ, pos)
+
+}
+
+// setValue sets the given key to the given value in the current context.
+// It will make sure that the key hasn't already been defined, account for
+// implicit key groups.
+func (p *parser) setValue(key string, value interface{}) {
+	var (
+		tmpHash    interface{}
+		ok         bool
+		hash       = p.mapping
+		keyContext Key
+	)
+	for _, k := range p.context {
+		keyContext = append(keyContext, k)
+		if tmpHash, ok = hash[k]; !ok {
+			p.bug("Context for key '%s' has not been established.", keyContext)
+		}
+		switch t := tmpHash.(type) {
+		case []map[string]interface{}:
+			// The context is a table of hashes. Pick the most recent table
+			// defined as the current hash.
+			hash = t[len(t)-1]
+		case map[string]interface{}:
+			hash = t
+		default:
+			p.panicf("Key '%s' has already been defined.", keyContext)
+		}
+	}
+	keyContext = append(keyContext, key)
+
+	if _, ok := hash[key]; ok {
+		// Normally redefining keys isn't allowed, but the key could have been
+		// defined implicitly and it's allowed to be redefined concretely. (See
+		// the `valid/implicit-and-explicit-after.toml` in toml-test)
+		//
+		// But we have to make sure to stop marking it as an implicit. (So that
+		// another redefinition provokes an error.)
+		//
+		// Note that since it has already been defined (as a hash), we don't
+		// want to overwrite it. So our business is done.
+		if p.isArray(keyContext) {
+			p.removeImplicit(keyContext)
+			hash[key] = value
+			return
+		}
+		if p.isImplicit(keyContext) {
+			p.removeImplicit(keyContext)
+			return
+		}
+
+		// Otherwise, we have a concrete key trying to override a previous
+		// key, which is *always* wrong.
+		p.panicf("Key '%s' has already been defined.", keyContext)
+	}
+
+	hash[key] = value
+}
+
+// setType sets the type of a particular value at a given key. It should be
+// called immediately AFTER setValue.
+//
+// Note that if `key` is empty, then the type given will be applied to the
+// current context (which is either a table or an array of tables).
+func (p *parser) setType(key string, typ tomlType, pos Position) {
+	keyContext := make(Key, 0, len(p.context)+1)
+	keyContext = append(keyContext, p.context...)
+	if len(key) > 0 { // allow type setting for hashes
+		keyContext = append(keyContext, key)
+	}
+	// Special case to make empty keys ("" = 1) work.
+	// Without it it will set "" rather than `""`.
+	// TODO: why is this needed? And why is this only needed here?
+	if len(keyContext) == 0 {
+		keyContext = Key{""}
+	}
+	p.keyInfo[keyContext.String()] = keyInfo{tomlType: typ, pos: pos}
+}
+
+// Implicit keys need to be created when tables are implied in "a.b.c.d = 1" and
+// "[a.b.c]" (the "a", "b", and "c" hashes are never created explicitly).
+func (p *parser) addImplicit(key Key)     { p.implicits[key.String()] = struct{}{} }
+func (p *parser) removeImplicit(key Key)  { delete(p.implicits, key.String()) }
+func (p *parser) isImplicit(key Key) bool { _, ok := p.implicits[key.String()]; return ok }
+func (p *parser) isArray(key Key) bool    { return p.keyInfo[key.String()].tomlType == tomlArray }
+func (p *parser) addImplicitContext(key Key) {
+	p.addImplicit(key)
+	p.addContext(key, false)
+}
+
+// current returns the full key name of the current context.
+func (p *parser) current() string {
+	if len(p.currentKey) == 0 {
+		return p.context.String()
+	}
+	if len(p.context) == 0 {
+		return p.currentKey
+	}
+	return fmt.Sprintf("%s.%s", p.context, p.currentKey)
+}
+
+func stripFirstNewline(s string) string {
+	if len(s) > 0 && s[0] == '\n' {
+		return s[1:]
+	}
+	if len(s) > 1 && s[0] == '\r' && s[1] == '\n' {
+		return s[2:]
+	}
+	return s
+}
+
+// Remove newlines inside triple-quoted strings if a line ends with "\".
+func (p *parser) stripEscapedNewlines(s string) string {
+	split := strings.Split(s, "\n")
+	if len(split) < 1 {
+		return s
+	}
+
+	escNL := false // Keep track of the last non-blank line was escaped.
+	for i, line := range split {
+		line = strings.TrimRight(line, " \t\r")
+
+		if len(line) == 0 || line[len(line)-1] != '\\' {
+			split[i] = strings.TrimRight(split[i], "\r")
+			if !escNL && i != len(split)-1 {
+				split[i] += "\n"
+			}
+			continue
+		}
+
+		escBS := true
+		for j := len(line) - 1; j >= 0 && line[j] == '\\'; j-- {
+			escBS = !escBS
+		}
+		if escNL {
+			line = strings.TrimLeft(line, " \t\r")
+		}
+		escNL = !escBS
+
+		if escBS {
+			split[i] += "\n"
+			continue
+		}
+
+		if i == len(split)-1 {
+			p.panicf("invalid escape: '\\ '")
+		}
+
+		split[i] = line[:len(line)-1] // Remove \
+		if len(split)-1 > i {
+			split[i+1] = strings.TrimLeft(split[i+1], " \t\r")
+		}
+	}
+	return strings.Join(split, "")
+}
+
+func (p *parser) replaceEscapes(it item, str string) string {
+	replaced := make([]rune, 0, len(str))
+	s := []byte(str)
+	r := 0
+	for r < len(s) {
+		if s[r] != '\\' {
+			c, size := utf8.DecodeRune(s[r:])
+			r += size
+			replaced = append(replaced, c)
+			continue
+		}
+		r += 1
+		if r >= len(s) {
+			p.bug("Escape sequence at end of string.")
+			return ""
+		}
+		switch s[r] {
+		default:
+			p.bug("Expected valid escape code after \\, but got %q.", s[r])
+		case ' ', '\t':
+			p.panicItemf(it, "invalid escape: '\\%c'", s[r])
+		case 'b':
+			replaced = append(replaced, rune(0x0008))
+			r += 1
+		case 't':
+			replaced = append(replaced, rune(0x0009))
+			r += 1
+		case 'n':
+			replaced = append(replaced, rune(0x000A))
+			r += 1
+		case 'f':
+			replaced = append(replaced, rune(0x000C))
+			r += 1
+		case 'r':
+			replaced = append(replaced, rune(0x000D))
+			r += 1
+		case '"':
+			replaced = append(replaced, rune(0x0022))
+			r += 1
+		case '\\':
+			replaced = append(replaced, rune(0x005C))
+			r += 1
+		case 'u':
+			// At this point, we know we have a Unicode escape of the form
+			// `uXXXX` at [r, r+5). (Because the lexer guarantees this
+			// for us.)
+			escaped := p.asciiEscapeToUnicode(it, s[r+1:r+5])
+			replaced = append(replaced, escaped)
+			r += 5
+		case 'U':
+			// At this point, we know we have a Unicode escape of the form
+			// `uXXXX` at [r, r+9). (Because the lexer guarantees this
+			// for us.)
+			escaped := p.asciiEscapeToUnicode(it, s[r+1:r+9])
+			replaced = append(replaced, escaped)
+			r += 9
+		}
+	}
+	return string(replaced)
+}
+
+func (p *parser) asciiEscapeToUnicode(it item, bs []byte) rune {
+	s := string(bs)
+	hex, err := strconv.ParseUint(strings.ToLower(s), 16, 32)
+	if err != nil {
+		p.bug("Could not parse '%s' as a hexadecimal number, but the lexer claims it's OK: %s", s, err)
+	}
+	if !utf8.ValidRune(rune(hex)) {
+		p.panicItemf(it, "Escaped character '\\u%s' is not valid UTF-8.", s)
+	}
+	return rune(hex)
+}

vendor/github.com/BurntSushi/toml/type_fields.go

@@ -0,0 +1,242 @@
+package toml
+
+// Struct field handling is adapted from code in encoding/json:
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the Go distribution.
+
+import (
+	"reflect"
+	"sort"
+	"sync"
+)
+
+// A field represents a single field found in a struct.
+type field struct {
+	name  string       // the name of the field (`toml` tag included)
+	tag   bool         // whether field has a `toml` tag
+	index []int        // represents the depth of an anonymous field
+	typ   reflect.Type // the type of the field
+}
+
+// byName sorts field by name, breaking ties with depth,
+// then breaking ties with "name came from toml tag", then
+// breaking ties with index sequence.
+type byName []field
+
+func (x byName) Len() int { return len(x) }
+
+func (x byName) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
+
+func (x byName) Less(i, j int) bool {
+	if x[i].name != x[j].name {
+		return x[i].name < x[j].name
+	}
+	if len(x[i].index) != len(x[j].index) {
+		return len(x[i].index) < len(x[j].index)
+	}
+	if x[i].tag != x[j].tag {
+		return x[i].tag
+	}
+	return byIndex(x).Less(i, j)
+}
+
+// byIndex sorts field by index sequence.
+type byIndex []field
+
+func (x byIndex) Len() int { return len(x) }
+
+func (x byIndex) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
+
+func (x byIndex) Less(i, j int) bool {
+	for k, xik := range x[i].index {
+		if k >= len(x[j].index) {
+			return false
+		}
+		if xik != x[j].index[k] {
+			return xik < x[j].index[k]
+		}
+	}
+	return len(x[i].index) < len(x[j].index)
+}
+
+// typeFields returns a list of fields that TOML should recognize for the given
+// type. The algorithm is breadth-first search over the set of structs to
+// include - the top struct and then any reachable anonymous structs.
+func typeFields(t reflect.Type) []field {
+	// Anonymous fields to explore at the current level and the next.
+	current := []field{}
+	next := []field{{typ: t}}
+
+	// Count of queued names for current level and the next.
+	var count map[reflect.Type]int
+	var nextCount map[reflect.Type]int
+
+	// Types already visited at an earlier level.
+	visited := map[reflect.Type]bool{}
+
+	// Fields found.
+	var fields []field
+
+	for len(next) > 0 {
+		current, next = next, current[:0]
+		count, nextCount = nextCount, map[reflect.Type]int{}
+
+		for _, f := range current {
+			if visited[f.typ] {
+				continue
+			}
+			visited[f.typ] = true
+
+			// Scan f.typ for fields to include.
+			for i := 0; i < f.typ.NumField(); i++ {
+				sf := f.typ.Field(i)
+				if sf.PkgPath != "" && !sf.Anonymous { // unexported
+					continue
+				}
+				opts := getOptions(sf.Tag)
+				if opts.skip {
+					continue
+				}
+				index := make([]int, len(f.index)+1)
+				copy(index, f.index)
+				index[len(f.index)] = i
+
+				ft := sf.Type
+				if ft.Name() == "" && ft.Kind() == reflect.Ptr {
+					// Follow pointer.
+					ft = ft.Elem()
+				}
+
+				// Record found field and index sequence.
+				if opts.name != "" || !sf.Anonymous || ft.Kind() != reflect.Struct {
+					tagged := opts.name != ""
+					name := opts.name
+					if name == "" {
+						name = sf.Name
+					}
+					fields = append(fields, field{name, tagged, index, ft})
+					if count[f.typ] > 1 {
+						// If there were multiple instances, add a second,
+						// so that the annihilation code will see a duplicate.
+						// It only cares about the distinction between 1 or 2,
+						// so don't bother generating any more copies.
+						fields = append(fields, fields[len(fields)-1])
+					}
+					continue
+				}
+
+				// Record new anonymous struct to explore in next round.
+				nextCount[ft]++
+				if nextCount[ft] == 1 {
+					f := field{name: ft.Name(), index: index, typ: ft}
+					next = append(next, f)
+				}
+			}
+		}
+	}
+
+	sort.Sort(byName(fields))
+
+	// Delete all fields that are hidden by the Go rules for embedded fields,
+	// except that fields with TOML tags are promoted.
+
+	// The fields are sorted in primary order of name, secondary order
+	// of field index length. Loop over names; for each name, delete
+	// hidden fields by choosing the one dominant field that survives.
+	out := fields[:0]
+	for advance, i := 0, 0; i < len(fields); i += advance {
+		// One iteration per name.
+		// Find the sequence of fields with the name of this first field.
+		fi := fields[i]
+		name := fi.name
+		for advance = 1; i+advance < len(fields); advance++ {
+			fj := fields[i+advance]
+			if fj.name != name {
+				break
+			}
+		}
+		if advance == 1 { // Only one field with this name
+			out = append(out, fi)
+			continue
+		}
+		dominant, ok := dominantField(fields[i : i+advance])
+		if ok {
+			out = append(out, dominant)
+		}
+	}
+
+	fields = out
+	sort.Sort(byIndex(fields))
+
+	return fields
+}
+
+// dominantField looks through the fields, all of which are known to
+// have the same name, to find the single field that dominates the
+// others using Go's embedding rules, modified by the presence of
+// TOML tags. If there are multiple top-level fields, the boolean
+// will be false: This condition is an error in Go and we skip all
+// the fields.
+func dominantField(fields []field) (field, bool) {
+	// The fields are sorted in increasing index-length order. The winner
+	// must therefore be one with the shortest index length. Drop all
+	// longer entries, which is easy: just truncate the slice.
+	length := len(fields[0].index)
+	tagged := -1 // Index of first tagged field.
+	for i, f := range fields {
+		if len(f.index) > length {
+			fields = fields[:i]
+			break
+		}
+		if f.tag {
+			if tagged >= 0 {
+				// Multiple tagged fields at the same level: conflict.
+				// Return no field.
+				return field{}, false
+			}
+			tagged = i
+		}
+	}
+	if tagged >= 0 {
+		return fields[tagged], true
+	}
+	// All remaining fields have the same length. If there's more than one,
+	// we have a conflict (two fields named "X" at the same level) and we
+	// return no field.
+	if len(fields) > 1 {
+		return field{}, false
+	}
+	return fields[0], true
+}
+
+var fieldCache struct {
+	sync.RWMutex
+	m map[reflect.Type][]field
+}
+
+// cachedTypeFields is like typeFields but uses a cache to avoid repeated work.
+func cachedTypeFields(t reflect.Type) []field {
+	fieldCache.RLock()
+	f := fieldCache.m[t]
+	fieldCache.RUnlock()
+	if f != nil {
+		return f
+	}
+
+	// Compute fields without lock.
+	// Might duplicate effort but won't hold other computations back.
+	f = typeFields(t)
+	if f == nil {
+		f = []field{}
+	}
+
+	fieldCache.Lock()
+	if fieldCache.m == nil {
+		fieldCache.m = map[reflect.Type][]field{}
+	}
+	fieldCache.m[t] = f
+	fieldCache.Unlock()
+	return f
+}

vendor/github.com/BurntSushi/toml/type_toml.go

@@ -0,0 +1,70 @@
+package toml
+
+// tomlType represents any Go type that corresponds to a TOML type.
+// While the first draft of the TOML spec has a simplistic type system that
+// probably doesn't need this level of sophistication, we seem to be militating
+// toward adding real composite types.
+type tomlType interface {
+	typeString() string
+}
+
+// typeEqual accepts any two types and returns true if they are equal.
+func typeEqual(t1, t2 tomlType) bool {
+	if t1 == nil || t2 == nil {
+		return false
+	}
+	return t1.typeString() == t2.typeString()
+}
+
+func typeIsTable(t tomlType) bool {
+	return typeEqual(t, tomlHash) || typeEqual(t, tomlArrayHash)
+}
+
+type tomlBaseType string
+
+func (btype tomlBaseType) typeString() string {
+	return string(btype)
+}
+
+func (btype tomlBaseType) String() string {
+	return btype.typeString()
+}
+
+var (
+	tomlInteger   tomlBaseType = "Integer"
+	tomlFloat     tomlBaseType = "Float"
+	tomlDatetime  tomlBaseType = "Datetime"
+	tomlString    tomlBaseType = "String"
+	tomlBool      tomlBaseType = "Bool"
+	tomlArray     tomlBaseType = "Array"
+	tomlHash      tomlBaseType = "Hash"
+	tomlArrayHash tomlBaseType = "ArrayHash"
+)
+
+// typeOfPrimitive returns a tomlType of any primitive value in TOML.
+// Primitive values are: Integer, Float, Datetime, String and Bool.
+//
+// Passing a lexer item other than the following will cause a BUG message
+// to occur: itemString, itemBool, itemInteger, itemFloat, itemDatetime.
+func (p *parser) typeOfPrimitive(lexItem item) tomlType {
+	switch lexItem.typ {
+	case itemInteger:
+		return tomlInteger
+	case itemFloat:
+		return tomlFloat
+	case itemDatetime:
+		return tomlDatetime
+	case itemString:
+		return tomlString
+	case itemMultilineString:
+		return tomlString
+	case itemRawString:
+		return tomlString
+	case itemRawMultilineString:
+		return tomlString
+	case itemBool:
+		return tomlBool
+	}
+	p.bug("Cannot infer primitive type of lex item '%s'.", lexItem)
+	panic("unreachable")
+}

vendor/github.com/siphiuel/lc-proxy-wrapper/.gitignore

@@ -0,0 +1,2 @@
+config.toml
+lc-proxy-wrapper

vendor/github.com/siphiuel/lc-proxy-wrapper/Makefile

@@ -0,0 +1,13 @@
+include Makefile.vars
+
+build-verif-proxy-wrapper:
+	CGO_CFLAGS="$(CGO_CFLAGS)" go build -x -v -ldflags $(LDFLAGS)
+
+build-verif-proxy-wrapper-exe:
+	CGO_CFLAGS="$(CGO_CFLAGS)" go build -x -v -ldflags $(LDFLAGS) -o verif-proxy-wrapper ./main 
+
+.PHONY: clean
+
+clean:
+	rm -rf nimcache libcb.a verif-proxy-wrapper
+

vendor/github.com/siphiuel/lc-proxy-wrapper/Makefile.vars

@@ -0,0 +1,15 @@
+NIMBUS_ETH1_PATH ?= $(CURDIR)/../nimbus-eth1
+NIMBASE_H_PATH ?= $(NIMBUS_ETH1_PATH)/vendor/nimbus-build-system/vendor/Nim-csources-v1/c_code/
+VERIF_PROXY_OUT_PATH ?= $(NIMBUS_ETH1_PATH)/build/libverifproxy
+
+CGO_CFLAGS += -I$(VERIF_PROXY_OUT_PATH) -I$(NIMBASE_H_PATH) 
+
+EXTLDFLAGS=-lverifproxy -L$(VERIF_PROXY_OUT_PATH)
+
+ifeq (, $(findstring darwin, $(OS)))
+	EXTLDFLAGS += -framework Security 
+endif
+
+LDFLAGS ?= '-v "-extldflags=$(EXTLDFLAGS)"'
+
+

vendor/github.com/siphiuel/lc-proxy-wrapper/README.md

@@ -0,0 +1,6 @@
+# Build Nim
+nim c --app:staticlib --header:cb.h --noMain:on --nimcache:$HOME/c/lc-proxy-wrapper/nimcache cb.nim
+
+# Build go
+go build
+./lc-proxy-wrapper

vendor/github.com/siphiuel/lc-proxy-wrapper/cb.nim

@@ -0,0 +1,27 @@
+{.pragma: some, header: "cb.h".}
+
+type
+  OnHeaderCallback = proc (s: cstring) {.cdecl.}
+
+proc callbackFn(json: string) {.exportc, cdecl.} =
+  echo "callbackFn", json
+
+# callbackFn "some"
+
+proc HelloFromNim(): cstring {.exportc.} = 
+    return "Hello, World From Nim\n"
+
+var headerCallback: OnHeaderCallback
+
+proc setHeaderCallback*(cb: OnHeaderCallback) {.exportc.} =
+  headerCallback = cb
+
+proc invokeHeaderCallback*() {.exportc.} =
+  headerCallback("inside Nim 2222")
+
+proc testEcho*() {.exportc.} =
+  echo "in testEcho"
+
+
+
+

vendor/github.com/siphiuel/lc-proxy-wrapper/cfuncs.go

@@ -0,0 +1,12 @@
+package proxy
+
+/*
+#include <stdio.h>
+
+void goCallback_cgo(char * json) {
+	printf("inside goCallback_cgo\n");
+	void goCallback(char *);
+	goCallback(json);
+}
+*/
+import "C"

vendor/github.com/siphiuel/lc-proxy-wrapper/proxy.go

@@ -0,0 +1,104 @@
+package proxy
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"runtime"
+	"unsafe"
+
+	"github.com/BurntSushi/toml"
+)
+
+/*
+#include <stdlib.h>
+#include "verifproxy.h"
+
+typedef void (*callback_type)(char *);
+void goCallback_cgo(char *);
+
+*/
+import "C"
+
+type Web3UrlType struct {
+	Kind    string `toml:"kind"`
+	Web3Url string `toml:"web3Url"`
+}
+type Config struct {
+	Eth2Network      string `toml:"network"`
+	TrustedBlockRoot string `toml:"trusted-block-root"`
+	// Web3Url          Web3UrlType `toml:"web3-url"`
+	Web3Url    string `toml:"web3-url"`
+	RpcAddress string `toml:"rpc-address"`
+	RpcPort    uint16 `toml:"rpc-port"`
+	LogLevel   string `toml:"log-level"`
+}
+
+type BeaconBlockHeader struct {
+	Slot          uint64 `json:"slot"`
+	ProposerIndex uint64 `json:"proposer_index"`
+	ParentRoot    string `json:"parent_root"`
+	StateRoot     string `json:"state_root"`
+}
+
+//export goCallback
+func goCallback(json *C.char) {
+	goStr := C.GoString(json)
+	//C.free(unsafe.Pointer(json))
+	fmt.Println("### goCallback " + goStr)
+	// var hdr BeaconBlockHeader
+	// err := json.NewDecoder([]byte(goStr)).Decode(&hdr)
+	// if err != nil {
+	// 	fmt.Println("### goCallback json parse error: " + err)
+	// }
+	// fmt.Println("Unmarshal result: " + hdr)
+}
+func createTomlFile(cfg *Config) string {
+	var buffer bytes.Buffer
+	err := toml.NewEncoder(&buffer).Encode(cfg)
+	if err != nil {
+		return ""
+	}
+	tomlFileName := "config.toml"
+	f, err := os.Create(tomlFileName)
+	if err != nil {
+		return ""
+	}
+	defer f.Close()
+	f.WriteString(buffer.String())
+
+	return tomlFileName
+}
+
+func StartLightClient(ctx context.Context, cfg *Config) {
+	fmt.Println("vim-go")
+	cb := (C.callback_type)(unsafe.Pointer(C.goCallback_cgo))
+	C.setOptimisticHeaderCallback(cb)
+	C.setFinalizedHeaderCallback(cb)
+	fmt.Println("vim-go 2")
+
+	go func() {
+		runtime.LockOSThread()
+		// tomlFileName := createTomlFile(cfg)
+		// configCStr := C.CString(tomlFileName)
+		// C.startLc(configCStr)
+		defer runtime.UnlockOSThread()
+		jsonBytes, _ := json.Marshal(cfg)
+		jsonStr := string(jsonBytes)
+		fmt.Println("### jsonStr: ", jsonStr)
+		configCStr := C.CString(jsonStr)
+		C.startProxyViaJson(configCStr)
+		fmt.Println("inside go-func after startLcViaJson")
+	}()
+	go func() {
+		fmt.Println("Before range ctx.Done()")
+		for range ctx.Done() {
+			fmt.Println("inside go-func ctx.Done()")
+			C.quit()
+		}
+	}()
+	fmt.Println("vim-go 3")
+
+}

vendor/modules.txt

@@ -1,3 +1,7 @@
+# github.com/BurntSushi/toml v1.2.1
+## explicit; go 1.16
+github.com/BurntSushi/toml
+github.com/BurntSushi/toml/internal
 # github.com/PuerkitoBio/goquery v1.6.1
 ## explicit; go 1.13
 github.com/PuerkitoBio/goquery
@@ -876,6 +880,9 @@ github.com/shirou/gopsutil/internal/common
 # github.com/shopspring/decimal v1.2.0
 ## explicit; go 1.13
 github.com/shopspring/decimal
+# github.com/siphiuel/lc-proxy-wrapper v0.0.0-20230516150924-246507cee8c7
+## explicit; go 1.18
+github.com/siphiuel/lc-proxy-wrapper
 # github.com/spaolacci/murmur3 v1.1.0
 ## explicit
 github.com/spaolacci/murmur3