NimYAML/test/testEventParser.nim

233 lines
7.6 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.
import "../yaml"
import lexbase
type
LexerToken = enum
plusStr, minusStr, plusDoc, minusDoc, plusMap, minusMap, plusSeq, minusSeq,
eqVal, eqAli, chevTag, andAnchor, quotContent, colonContent, noToken
StreamPos = enum
beforeStream, inStream, afterStream
EventLexer = object of BaseLexer
content: string
EventStreamError = object of Exception
proc nextToken(lex: var EventLexer): LexerToken =
while true:
case lex.buf[lex.bufpos]
of ' ', '\t': lex.bufpos.inc()
of '\r': lex.bufpos = lex.handleCR(lex.bufpos)
of '\l': lex.bufpos = lex.handleLF(lex.bufpos)
else: break
if lex.buf[lex.bufpos] == EndOfFile: return noToken
case lex.buf[lex.bufpos]
of ':', '"':
let t = if lex.buf[lex.bufpos] == ':': colonContent else: quotContent
lex.content = ""
lex.bufpos.inc()
while true:
case lex.buf[lex.bufpos]
of EndOfFile: break
of '\c':
lex.bufpos = lex.handleCR(lex.bufpos)
break
of '\l':
lex.bufpos = lex.handleLF(lex.bufpos)
break
of '\\':
lex.bufpos.inc()
case lex.buf[lex.bufpos]
of 'n': lex.content.add('\l')
of 'r': lex.content.add('\r')
of '0': lex.content.add('\0')
of 'b': lex.content.add('\b')
of 't': lex.content.add('\t')
of '\\': lex.content.add('\\')
else: raise newException(EventStreamError,
"Unknown escape character: " & lex.buf[lex.bufpos])
else: lex.content.add(lex.buf[lex.bufpos])
lex.bufpos.inc()
result = t
of '<':
lex.content = ""
lex.bufpos.inc()
while lex.buf[lex.bufpos] != '>':
lex.content.add(lex.buf[lex.bufpos])
lex.bufpos.inc()
if lex.buf[lex.bufpos] == EndOfFile:
raise newException(EventStreamError, "Unclosed tag URI!")
result = chevTag
lex.bufpos.inc()
of '&':
lex.content = ""
lex.bufpos.inc()
while lex.buf[lex.bufpos] notin {' ', '\t', '\r', '\l', EndOfFile}:
lex.content.add(lex.buf[lex.bufpos])
lex.bufpos.inc()
result = andAnchor
else:
lex.content = ""
while lex.buf[lex.bufpos] notin {' ', '\t', '\r', '\l', EndOfFile}:
lex.content.add(lex.buf[lex.bufpos])
lex.bufpos.inc()
case lex.content
of "+STR": result = plusStr
of "-STR": result = minusStr
of "+DOC": result = plusDoc
of "-DOC": result = minusDoc
of "+MAP": result = plusMap
of "-MAP": result = minusMap
of "+SEQ": result = plusSeq
of "-SEQ": result = minusSeq
of "=VAL": result = eqVal
of "=ALI": result = eqAli
else: raise newException(EventStreamError, "Invalid token: " & lex.content)
template assertInStream() {.dirty.} =
if streamPos != inStream:
raise newException(EventStreamError, "Missing +STR")
template assertInEvent(name: string) {.dirty.} =
if not inEvent:
raise newException(EventStreamError, "Illegal token: " & name)
template yieldEvent() {.dirty.} =
if inEvent:
yield curEvent
inEvent = false
template setTag(t: TagId) {.dirty.} =
case curEvent.kind
of yamlStartSeq: curEvent.seqTag = t
of yamlStartMap: curEvent.mapTag = t
of yamlScalar: curEvent.scalarTag = t
else: discard
template setAnchor(a: AnchorId) {.dirty.} =
case curEvent.kind
of yamlStartSeq: curEvent.seqAnchor = a
of yamlStartMap: curEvent.mapAnchor = a
of yamlScalar: curEvent.scalarAnchor = a
of yamlAlias: curEvent.aliasTarget = a
else: discard
template curTag(): TagId =
var foo: TagId
case curEvent.kind
of yamlStartSeq: foo = curEvent.seqTag
of yamlStartMap: foo = curEvent.mapTag
of yamlScalar: foo = curEvent.scalarTag
else: raise newException(EventStreamError,
$curEvent.kind & " may not have a tag")
foo
template setCurTag(val: TagId) =
case curEvent.kind
of yamlStartSeq: curEvent.seqTag = val
of yamlStartMap: curEvent.mapTag = val
of yamlScalar: curEvent.scalarTag = val
else: raise newException(EventStreamError,
$curEvent.kind & " may not have a tag")
template curAnchor(): AnchorId =
var foo: AnchorId
case curEvent.kind
of yamlStartSeq: foo = curEvent.seqAnchor
of yamlStartMap: foo = curEvent.mapAnchor
of yamlScalar: foo = curEvent.scalarAnchor
of yamlAlias: foo = curEvent.aliasTarget
else: raise newException(EventStreamError,
$curEvent.kind & "may not have an anchor")
foo
template setCurAnchor(val: AnchorId) =
case curEvent.kind
of yamlStartSeq: curEvent.seqAnchor = val
of yamlStartMap: curEvent.mapAnchor = val
of yamlScalar: curEvent.scalarAnchor = val
of yamlAlias: curEvent.aliasTarget = val
else: raise newException(EventStreamError,
$curEvent.kind & " may not have an anchor")
template eventStart(k: YamlStreamEventKind) {.dirty.} =
assertInStream()
yieldEvent()
reset(curEvent)
curEvent.kind = k
setTag(yTagQuestionMark)
setAnchor(yAnchorNone)
inEvent = true
proc parseEventStream*(input: Stream, tagLib: TagLibrary): YamlStream =
var backend = iterator(): YamlStreamEvent =
var lex: EventLexer
lex.open(input)
var
inEvent = false
curEvent: YamlStreamEvent
streamPos = beforeStream
anchors = initTable[string, AnchorId]()
nextAnchorId = 0.AnchorId
while lex.buf[lex.bufpos] != EndOfFile:
let token = lex.nextToken()
case token
of plusStr:
if streamPos != beforeStream:
raise newException(EventStreamError, "Illegal +STR")
streamPos = inStream
of minusStr:
if streamPos != inStream:
raise newException(EventStreamError, "Illegal -STR")
if inEvent: yield curEvent
inEvent = false
streamPos = afterStream
of plusDoc: eventStart(yamlStartDoc)
of minusDoc: eventStart(yamlEndDoc)
of plusMap: eventStart(yamlStartMap)
of minusMap: eventStart(yamlEndMap)
of plusSeq: eventStart(yamlStartSeq)
of minusSeq: eventStart(yamlEndSeq)
of eqVal: eventStart(yamlScalar)
of eqAli: eventStart(yamlAlias)
of chevTag:
assertInEvent("tag")
if curTag() != yTagQuestionMark:
raise newException(EventStreamError,
"Duplicate tag in " & $curEvent.kind)
try:
setCurTag(tagLib.tags[lex.content])
except KeyError: setCurTag(tagLib.registerUri(lex.content))
of andAnchor:
assertInEvent("anchor")
if curAnchor() != yAnchorNone:
raise newException(EventStreamError,
"Duplicate anchor in " & $curEvent.kind)
if curEvent.kind == yamlAlias:
curEvent.aliasTarget = anchors[lex.content]
else:
anchors[lex.content] = nextAnchorId
setCurAnchor(nextAnchorId)
nextAnchorId = (AnchorId)(((int)nextAnchorId) + 1)
of quotContent:
assertInEvent("scalar content")
if curTag() == yTagQuestionMark: setCurTag(yTagExclamationMark)
if curEvent.kind != yamlScalar:
raise newException(EventStreamError,
"scalar content in non-scalar tag")
curEvent.scalarContent = lex.content
of colonContent:
assertInEvent("scalar content")
curEvent.scalarContent = lex.content
if curEvent.kind != yamlScalar:
raise newException(EventStreamError,
"scalar content in non-scalar tag")
of noToken: discard
result = initYamlStream(backend)