NimYAML/yaml/taglib.nim

177 lines
6.3 KiB
Nim

# NimYAML - YAML implementation in Nim
# (c) Copyright 2016 Felix Krause
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
## ==================
## Module yaml.taglib
## ==================
##
## The taglib API enables you to query real names of tags emitted by the parser
## and create own tags. It also enables you to define tags for types used with
## the serialization API.
import tables, macros, hashes
import data
type
TagLibrary* = ref object
## A ``TagLibrary`` maps tag URIs to ``TagId`` s.
##
## When `YamlParser <#YamlParser>`_ encounters tags not existing in the
## tag library, it will use
## `registerUri <#registerUri,TagLibrary,string>`_ to add
## the tag to the library.
##
## You can base your tag library on common tag libraries by initializing
## them with `initFailsafeTagLibrary <#initFailsafeTagLibrary>`_,
## `initCoreTagLibrary <#initCoreTagLibrary>`_ or
## `initExtendedTagLibrary <#initExtendedTagLibrary>`_.
tags*: Table[string, Tag]
proc initTagLibrary*(): TagLibrary {.raises: [].} =
## initializes the ``tags`` table and sets ``nextCustomTagId`` to
## ``yFirstCustomTagId``.
new(result)
result.tags = initTable[string, Tag]()
proc registerUri*(tagLib: TagLibrary, uri: string): Tag {.raises: [].} =
## registers a custom tag URI with a ``TagLibrary``. The URI will get
## the ``TagId`` ``nextCustomTagId``, which will be incremented.
result = uri.Tag
tagLib.tags[uri] = result
template y(suffix: string): string = yamlTagRepositoryPrefix & suffix
template n(suffix: string): string = nimyamlTagRepositoryPrefix & suffix
proc initFailsafeTagLibrary*(): TagLibrary {.raises: [].} =
## Contains only:
## - ``!``
## - ``?``
## - ``!!str``
## - ``!!map``
## - ``!!seq``
result = initTagLibrary()
result.tags["!"] = yTagExclamationMark
result.tags["?"] = yTagQuestionMark
result.tags[y"str"] = yTagString
result.tags[y"seq"] = yTagSequence
result.tags[y"map"] = yTagMapping
proc initCoreTagLibrary*(): TagLibrary {.raises: [].} =
## Contains everything in ``initFailsafeTagLibrary`` plus:
## - ``!!null``
## - ``!!bool``
## - ``!!int``
## - ``!!float``
result = initFailsafeTagLibrary()
result.tags[y"null"] = yTagNull
result.tags[y"bool"] = yTagBoolean
result.tags[y"int"] = yTagInteger
result.tags[y"float"] = yTagFloat
proc initExtendedTagLibrary*(): TagLibrary {.raises: [].} =
## Contains everything from ``initCoreTagLibrary`` plus:
## - ``!!omap``
## - ``!!pairs``
## - ``!!set``
## - ``!!binary``
## - ``!!merge``
## - ``!!timestamp``
## - ``!!value``
## - ``!!yaml``
result = initCoreTagLibrary()
result.tags[y"omap"] = yTagOrderedMap
result.tags[y"pairs"] = yTagPairs
result.tags[y"binary"] = yTagBinary
result.tags[y"merge"] = yTagMerge
result.tags[y"timestamp"] = yTagTimestamp
result.tags[y"value"] = yTagValue
result.tags[y"yaml"] = yTagYaml
proc initSerializationTagLibrary*(): TagLibrary =
result = initTagLibrary()
result.tags["!"] = yTagExclamationMark
result.tags["?"] = yTagQuestionMark
result.tags[y"str"] = yTagString
result.tags[y"null"] = yTagNull
result.tags[y"bool"] = yTagBoolean
result.tags[y"float"] = yTagFloat
result.tags[y"timestamp"] = yTagTimestamp
result.tags[y"value"] = yTagValue
result.tags[y"binary"] = yTagBinary
result.tags[n"field"] = yTagNimField
var
serializationTagLibrary* {.compileTime.} = initSerializationTagLibrary() ## \
## contains all local tags that are used for type serialization. Does
## not contain any of the specific default tags for sequences or maps,
## as those are not suited for Nim's static type system.
##
## Should not be modified manually. Will be extended by
## `serializable <#serializable,stmt,stmt>`_.
var
registeredUris {.compileTime.} = newSeq[string]() ## \
## Since Table doesn't really work at compile time, we also store
## registered URIs here to be able to generate a static compiler error
## when the user tries to register an URI more than once.
template setTagUri*(t: typedesc, uri: string) =
## Associate the given uri with a certain type. This uri is used as YAML tag
## when loading and dumping values of this type.
when uri in registeredUris:
{. fatal: "[NimYAML] URI \"" & uri & "\" registered twice!" .}
const tag {.genSym.} = uri.Tag
static:
registeredUris.add(uri)
serializationTagLibrary.tags[uri] = tag
proc yamlTag*(T: typedesc[t]): Tag {.inline, raises: [].} = tag
## autogenerated
template setTagUri*(t: typedesc, uri: string, idName: untyped) =
## Like `setTagUri <#setTagUri.t,typedesc,string>`_, but lets
## you choose a symbol for the `TagId <#TagId>`_ of the uri. This is only
## necessary if you want to implement serialization / construction yourself.
when uri in registeredUris:
{. fatal: "[NimYAML] URI \"" & uri & "\" registered twice!" .}
const idName* = uri.Tag
static:
registeredUris.add(uri)
serializationTagLibrary.tags[uri] = idName
proc yamlTag*(T: typedesc[t]): Tag {.inline, raises: [].} = idName
## autogenerated
static:
# standard YAML tags used by serialization
registeredUris.add("!")
registeredUris.add("?")
registeredUris.add(y"str")
registeredUris.add(y"null")
registeredUris.add(y"bool")
registeredUris.add(y"float")
registeredUris.add(y"timestamp")
registeredUris.add(y"value")
registeredUris.add(y"binary")
# special tags used by serialization
registeredUris.add(n"field")
# tags for Nim's standard types
setTagUri(char, n"system:char", yTagNimChar)
setTagUri(int8, n"system:int8", yTagNimInt8)
setTagUri(int16, n"system:int16", yTagNimInt16)
setTagUri(int32, n"system:int32", yTagNimInt32)
setTagUri(int64, n"system:int64", yTagNimInt64)
setTagUri(uint8, n"system:uint8", yTagNimUInt8)
setTagUri(uint16, n"system:uint16", yTagNimUInt16)
setTagUri(uint32, n"system:uint32", yTagNimUInt32)
setTagUri(uint64, n"system:uint64", yTagNimUInt64)
setTagUri(float32, n"system:float32", yTagNimFloat32)
setTagUri(float64, n"system:float64", yTagNimFloat64)
proc nimTag*(suffix: string): string =
## prepends NimYAML's tag repository prefix to the given suffix. For example,
## ``nimTag("system:char")`` yields ``"tag:nimyaml.org,2016:system:char"``.
nimyamlTagRepositoryPrefix & suffix