nim-stew/stew/shims/macros.nim

430 lines
13 KiB
Nim

import
std/[macros, tables, hashes]
export
macros
type
FieldDescription* = object
name*: NimNode
isPublic*: bool
isDiscriminator*: bool
typ*: NimNode
pragmas*: NimNode
caseField*: NimNode
caseBranch*: NimNode
const
nnkPragmaCallKinds = {nnkExprColonExpr, nnkCall, nnkCallStrLit}
proc hash*(x: LineInfo): Hash =
!$(hash(x.filename) !& hash(x.line) !& hash(x.column))
var
# Please note that we are storing NimNode here in order to
# incur the code rendering cost only on a successful compilation.
macroLocations {.compileTime.} = newSeq[LineInfo]()
macroOutputs {.compileTime.} = newSeq[NimNode]()
proc writeMacroResultsNow* {.compileTime.} =
var files = initTable[string, NimNode]()
proc addToFile(file: var NimNode, location: LineInfo, macroOutput: NimNode) =
if file == nil:
file = newNimNode(nnkStmtList, macroOutput)
file.add newCommentStmtNode("Generated at line " & $location.line)
file.add macroOutput
for i in 0..< macroLocations.len:
addToFile files.mgetOrPut(macroLocations[i].filename, nil),
macroLocations[i], macroOutputs[i]
for name, contents in files:
let targetFile = name & ".generated.nim"
writeFile(targetFile, repr(contents))
hint "Wrote macro output to " & targetFile, contents
proc storeMacroResult*(callSite: LineInfo,
macroResult: NimNode,
writeOutputImmediately = false) =
macroLocations.add callSite
macroOutputs.add macroResult
if writeOutputImmediately:
# echo macroResult.repr
writeMacroResultsNow()
proc storeMacroResult*(macroResult: NimNode, writeOutputImmediately = false) =
let usageSite = callsite().lineInfoObj
storeMacroResult(usageSite, macroResult, writeOutputImmediately)
macro dumpMacroResults*: untyped =
writeMacroResultsNow()
proc findPragma*(pragmas: NimNode, pragmaSym: NimNode): NimNode =
for p in pragmas:
if p.kind in {nnkSym, nnkIdent} and eqIdent(p, pragmaSym):
return p
if p.kind in nnkPragmaCallKinds and p.len > 0 and eqIdent(p[0], pragmaSym):
return p
func isTuple*(t: NimNode): bool =
t.kind == nnkBracketExpr and t[0].kind == nnkSym and eqIdent(t[0], "tuple")
macro isTuple*(T: type): untyped =
newLit(isTuple(getType(T)[1]))
proc skipRef*(T: NimNode): NimNode =
result = T
if T.kind == nnkBracketExpr:
if eqIdent(T[0], bindSym"ref"):
result = T[1]
template readPragma*(field: FieldDescription, pragmaName: static string): NimNode =
let p = findPragma(field.pragmas, bindSym(pragmaName))
if p != nil and p.len == 2: p[1] else: p
proc collectFieldsFromRecList(result: var seq[FieldDescription],
n: NimNode,
parentCaseField: NimNode = nil,
parentCaseBranch: NimNode = nil,
isDiscriminator = false) =
case n.kind
of nnkRecList:
for entry in n:
collectFieldsFromRecList result, entry,
parentCaseField, parentCaseBranch
of nnkRecWhen:
for branch in n:
case branch.kind:
of nnkElifBranch:
collectFieldsFromRecList result, branch[1],
parentCaseField, parentCaseBranch
of nnkElse:
collectFieldsFromRecList result, branch[0],
parentCaseField, parentCaseBranch
else:
doAssert false
of nnkRecCase:
collectFieldsFromRecList result, n[0],
parentCaseField,
parentCaseBranch,
isDiscriminator = true
for i in 1 ..< n.len:
let branch = n[i]
case branch.kind
of nnkOfBranch:
collectFieldsFromRecList result, branch[^1], n[0], branch
of nnkElse:
collectFieldsFromRecList result, branch[0], n[0], branch
else:
doAssert false
of nnkIdentDefs:
let fieldType = n[^2]
for i in 0 ..< n.len - 2:
var field: FieldDescription
field.name = n[i]
field.typ = fieldType
field.caseField = parentCaseField
field.caseBranch = parentCaseBranch
field.isDiscriminator = isDiscriminator
if field.name.kind == nnkPragmaExpr:
field.pragmas = field.name[1]
field.name = field.name[0]
if field.name.kind == nnkPostfix:
field.isPublic = true
field.name = field.name[1]
result.add field
of nnkSym:
result.add FieldDescription(
name: n,
typ: getType(n),
caseField: parentCaseField,
caseBranch: parentCaseBranch,
isDiscriminator: isDiscriminator)
of nnkNilLit, nnkDiscardStmt, nnkCommentStmt, nnkEmpty:
discard
else:
doAssert false, "Unexpected nodes in recordFields:\n" & n.treeRepr
proc collectFieldsInHierarchy(result: var seq[FieldDescription],
objectType: NimNode) =
var objectType = objectType
objectType.expectKind {nnkObjectTy, nnkRefTy}
if objectType.kind == nnkRefTy:
objectType = objectType[0]
objectType.expectKind nnkObjectTy
var baseType = objectType[1]
if baseType.kind != nnkEmpty:
baseType.expectKind nnkOfInherit
baseType = baseType[0]
baseType.expectKind nnkSym
baseType = getImpl(baseType)
baseType.expectKind nnkTypeDef
baseType = baseType[2]
baseType.expectKind {nnkObjectTy, nnkRefTy}
collectFieldsInHierarchy result, baseType
let recList = objectType[2]
collectFieldsFromRecList result, recList
proc recordFields*(typeImpl: NimNode): seq[FieldDescription] =
if typeImpl.isTuple:
for i in 1 ..< typeImpl.len:
result.add FieldDescription(typ: typeImpl[i], name: ident("Field" & $(i - 1)))
return
typeImpl.expectKind nnkTypeDef
collectFieldsInHierarchy(result, typeImpl[2])
macro field*(obj: typed, fieldName: static string): untyped =
newDotExpr(obj, ident fieldName)
proc skipPragma*(n: NimNode): NimNode =
if n.kind == nnkPragmaExpr: n[0]
else: n
proc getPragma(T: NimNode, lookedUpField: string, pragma: NimNode): NimNode =
let Tresolved = getType(T)[1]
if isTuple(Tresolved):
return nil
for f in recordFields(Tresolved.getImpl):
var fieldName = f.name
# TODO: Fix this in eqIdent
if fieldName.kind == nnkAccQuoted: fieldName = fieldName[0]
if eqIdent(fieldName, lookedUpField):
return f.pragmas.findPragma(pragma)
error "The type " & $Tresolved & " doesn't have a field named " & lookedUpField
macro getCustomPragmaFixed*(T: type, field: static string, pragma: typed{nkSym}): untyped =
let p = getPragma(T, field, pragma)
if p != nil and p.len == 2: p[1] else: p
macro hasCustomPragmaFixed*(T: type, field: static string, pragma: typed{nkSym}): untyped =
newLit(getPragma(T, field, pragma) != nil)
proc humaneTypeName*(typedescNode: NimNode): string =
var t = getType(typedescNode)[1]
if t.kind != nnkBracketExpr:
let tImpl = t.getImpl
if tImpl != nil and tImpl.kind notin {nnkEmpty, nnkNilLit}:
t = tImpl
repr(t)
macro inspectType*(T: typed): untyped =
echo "Inspect type: ", humaneTypeName(T)
# FIXED NewLit
proc newLitFixed*(c: char): NimNode {.compileTime.} =
## Produces a new character literal node.
result = newNimNode(nnkCharLit)
result.intVal = ord(c)
proc newLitFixed*(i: int): NimNode {.compileTime.} =
## Produces a new integer literal node.
result = newNimNode(nnkIntLit)
result.intVal = i
proc newLitFixed*(i: int8): NimNode {.compileTime.} =
## Produces a new integer literal node.
result = newNimNode(nnkInt8Lit)
result.intVal = i
proc newLitFixed*(i: int16): NimNode {.compileTime.} =
## Produces a new integer literal node.
result = newNimNode(nnkInt16Lit)
result.intVal = i
proc newLitFixed*(i: int32): NimNode {.compileTime.} =
## Produces a new integer literal node.
result = newNimNode(nnkInt32Lit)
result.intVal = i
proc newLitFixed*(i: int64): NimNode {.compileTime.} =
## Produces a new integer literal node.
result = newNimNode(nnkInt64Lit)
result.intVal = i
proc newLitFixed*(i: uint): NimNode {.compileTime.} =
## Produces a new unsigned integer literal node.
result = newNimNode(nnkUIntLit)
result.intVal = BiggestInt(i)
proc newLitFixed*(i: uint8): NimNode {.compileTime.} =
## Produces a new unsigned integer literal node.
result = newNimNode(nnkUInt8Lit)
result.intVal = BiggestInt(i)
proc newLitFixed*(i: uint16): NimNode {.compileTime.} =
## Produces a new unsigned integer literal node.
result = newNimNode(nnkUInt16Lit)
result.intVal = BiggestInt(i)
proc newLitFixed*(i: uint32): NimNode {.compileTime.} =
## Produces a new unsigned integer literal node.
result = newNimNode(nnkUInt32Lit)
result.intVal = BiggestInt(i)
proc newLitFixed*(i: uint64): NimNode {.compileTime.} =
## Produces a new unsigned integer literal node.
result = newNimNode(nnkUInt64Lit)
result.intVal = BiggestInt(i)
proc newLitFixed*(b: bool): NimNode {.compileTime.} =
## Produces a new boolean literal node.
result = if b: bindSym"true" else: bindSym"false"
proc newLitFixed*(s: string): NimNode {.compileTime.} =
## Produces a new string literal node.
result = newNimNode(nnkStrLit)
result.strVal = s
when false:
# the float type is not really a distinct type as described in https://github.com/nim-lang/Nim/issues/5875
proc newLitFixed*(f: float): NimNode {.compileTime.} =
## Produces a new float literal node.
result = newNimNode(nnkFloatLit)
result.floatVal = f
proc newLitFixed*(f: float32): NimNode {.compileTime.} =
## Produces a new float literal node.
result = newNimNode(nnkFloat32Lit)
result.floatVal = f
proc newLitFixed*(f: float64): NimNode {.compileTime.} =
## Produces a new float literal node.
result = newNimNode(nnkFloat64Lit)
result.floatVal = f
when declared(float128):
proc newLitFixed*(f: float128): NimNode {.compileTime.} =
## Produces a new float literal node.
result = newNimNode(nnkFloat128Lit)
result.floatVal = f
proc newLitFixed*(arg: enum): NimNode {.compileTime.} =
result = newCall(
arg.type.getTypeInst[1],
newLitFixed(int(arg))
)
proc newLitFixed*[N,T](arg: array[N,T]): NimNode {.compileTime.}
proc newLitFixed*[T](arg: seq[T]): NimNode {.compileTime.}
proc newLitFixed*[T](s: set[T]): NimNode {.compileTime.}
proc newLitFixed*(arg: tuple): NimNode {.compileTime.}
proc newLitFixed*(arg: object): NimNode {.compileTime.} =
result = nnkObjConstr.newTree(arg.type.getTypeInst[1])
for a, b in arg.fieldPairs:
result.add nnkExprColonExpr.newTree( newIdentNode(a), newLitFixed(b) )
proc newLitFixed*(arg: ref object): NimNode {.compileTime.} =
## produces a new ref type literal node.
result = nnkObjConstr.newTree(arg.type.getTypeInst[1])
for a, b in fieldPairs(arg[]):
result.add nnkExprColonExpr.newTree(newIdentNode(a), newLitFixed(b))
proc newLitFixed*[N,T](arg: array[N,T]): NimNode {.compileTime.} =
result = nnkBracket.newTree
for x in arg:
result.add newLitFixed(x)
proc newLitFixed*[T](arg: seq[T]): NimNode {.compileTime.} =
let bracket = nnkBracket.newTree
for x in arg:
bracket.add newLitFixed(x)
result = nnkPrefix.newTree(
bindSym"@",
bracket
)
if arg.len == 0:
# add type cast for empty seq
var typ = getTypeInst(typeof(arg))[1]
result = newCall(typ,result)
proc newLitFixed*[T](s: set[T]): NimNode {.compileTime.} =
result = nnkCurly.newTree
for x in s:
result.add newLitFixed(x)
proc newLitFixed*(arg: tuple): NimNode {.compileTime.} =
result = nnkPar.newTree
for a,b in arg.fieldPairs:
result.add nnkExprColonExpr.newTree(newIdentNode(a), newLitFixed(b))
iterator typedParams*(n: NimNode, skip = 0): (NimNode, NimNode) =
let params = n[3]
for i in (1 + skip) ..< params.len:
let paramNodes = params[i]
let paramType = paramNodes[^2]
for j in 0 ..< paramNodes.len - 2:
yield (skipPragma paramNodes[j], paramType)
iterator baseTypes*(exceptionType: NimNode): NimNode =
var typ = exceptionType
while typ != nil:
let impl = getImpl(typ)
if impl.len != 3 or impl[2].kind != nnkObjectTy:
break
let objType = impl[2]
if objType[1].kind != nnkOfInherit:
break
typ = objType[1][0]
yield typ
macro unpackArgs*(callee: typed, args: untyped): untyped =
result = newCall(callee)
for arg in args:
let arg = if arg.kind == nnkHiddenStdConv: arg[1]
else: arg
if arg.kind == nnkArgList:
for subarg in arg:
result.add subarg
else:
result.add arg
template genExpr*(treeType: NimNodeKind, body: untyped): untyped =
iterator generator: NimNode = body
macro payload: untyped =
result = newTree(treeType)
for node in generator():
result.add node
payload()
template genStmtList*(body: untyped) =
iterator generator: NimNode = body
macro payload: untyped =
result = newStmtList()
for node in generator():
result.add node
payload()
template genSimpleExpr*(body: untyped): untyped =
macro payload: untyped = body
payload()