NimYAML/private/tagLibrary.nim

#            NimYAML - YAML implementation in Nim
#        (c) Copyright 2015 Felix Krause
#
#    See the file "copying.txt", included in this
#    distribution, for details about the copyright.

proc `$`*(id: TagId): string =
    case id
    of yTagQuestionMark: "?"
    of yTagExclamationMark: "!"
    of yTagString: "!!str"
    of yTagSequence: "!!seq"
    of yTagMap: "!!map"
    of yTagNull: "!!null"
    of yTagBoolean: "!!bool"
    of yTagInteger: "!!int"
    of yTagFloat: "!!float"
    of yTagOrderedMap: "!!omap"
    of yTagPairs: "!!pairs"
    of yTagSet: "!!set"
    of yTagBinary: "!!binary"
    of yTagMerge: "!!merge"
    of yTagTimestamp: "!!timestamp"
    of yTagValue: "!!value"
    of yTagYaml: "!!yaml"
    else:
        "<" & $cast[int](id) & ">"

proc initTagLibrary*(): TagLibrary =
    new(result)
    result.tags = initTable[string, TagId]()
    result.secondaryPrefix = yamlTagRepositoryPrefix
    result.nextCustomTagId = yFirstCustomTagId

proc registerUri*(tagLib: TagLibrary, uri: string): TagId =  
    tagLib.tags[uri] = tagLib.nextCustomTagId
    result = tagLib.nextCustomTagId
    tagLib.nextCustomTagId = cast[TagId](cast[int](tagLib.nextCustomTagId) + 1)
    
proc uri*(tagLib: TagLibrary, id: TagId): string =
    for iUri, iId in tagLib.tags.pairs:
        if iId == id:
            return iUri
    raise newException(KeyError, "Unknown tag id: " & $id)

proc initFailsafeTagLibrary(): TagLibrary =
    result = initTagLibrary()
    result.tags["!"] = yTagExclamationMark
    result.tags["?"] = yTagQuestionMark
    result.tags["tag:yaml.org,2002:str"] = yTagString
    result.tags["tag:yaml.org,2002:seq"] = yTagSequence
    result.tags["tag:yaml.org,2002:map"] = yTagMap

proc initCoreTagLibrary(): TagLibrary =
    result = initFailsafeTagLibrary()
    result.tags["tag:yaml.org,2002:null"]  = yTagNull
    result.tags["tag:yaml.org,2002:bool"]  = yTagBoolean
    result.tags["tag:yaml.org,2002:int"]   = yTagInteger
    result.tags["tag:yaml.org,2002:float"] = yTagFloat

proc initExtendedTagLibrary(): TagLibrary =
    result = initCoreTagLibrary()
    result.tags["tag:yaml.org,2002:omap"]      = yTagOrderedMap
    result.tags["tag:yaml.org,2002:pairs"]     = yTagPairs
    result.tags["tag:yaml.org,2002:binary"]    = yTagBinary
    result.tags["tag:yaml.org,2002:merge"]     = yTagMerge
    result.tags["tag:yaml.org,2002:timestamp"] = yTagTimestamp
    result.tags["tag:yaml.org,2002:value"]     = yTagValue
    result.tags["tag:yaml.org,2002:yaml"]      = yTagYaml