mirror of
https://github.com/nim-lang/Nim.git
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move parsejson logic into its own standard lib module
This commit is contained in:
Araq
@@ -89,506 +89,21 @@
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## echo j2
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import
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hashes, tables, strutils, lexbase, streams, unicode, macros
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hashes, tables, strutils, lexbase, streams, unicode, macros, parsejson
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export
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tables.`$`
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export
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parsejson.JsonEventKind, parsejson.JsonError, JsonParser, JsonKindError,
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open, close, str, getInt, getFloat, kind, getColumn, getLine, getFilename,
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errorMsg, errorMsgExpected, next, JsonParsingError, raiseParseErr
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when defined(nimJsonGet):
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{.pragma: deprecatedGet, deprecated.}
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else:
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{.pragma: deprecatedGet.}
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type
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JsonEventKind* = enum ## enumeration of all events that may occur when parsing
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jsonError, ## an error occurred during parsing
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jsonEof, ## end of file reached
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jsonString, ## a string literal
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jsonInt, ## an integer literal
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jsonFloat, ## a float literal
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jsonTrue, ## the value ``true``
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jsonFalse, ## the value ``false``
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jsonNull, ## the value ``null``
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jsonObjectStart, ## start of an object: the ``{`` token
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jsonObjectEnd, ## end of an object: the ``}`` token
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jsonArrayStart, ## start of an array: the ``[`` token
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jsonArrayEnd ## start of an array: the ``]`` token
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TokKind = enum # must be synchronized with TJsonEventKind!
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tkError,
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tkEof,
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tkString,
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tkInt,
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tkFloat,
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tkTrue,
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tkFalse,
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tkNull,
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tkCurlyLe,
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tkCurlyRi,
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tkBracketLe,
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tkBracketRi,
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tkColon,
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tkComma
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JsonError* = enum ## enumeration that lists all errors that can occur
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errNone, ## no error
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errInvalidToken, ## invalid token
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errStringExpected, ## string expected
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errColonExpected, ## ``:`` expected
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errCommaExpected, ## ``,`` expected
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errBracketRiExpected, ## ``]`` expected
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errCurlyRiExpected, ## ``}`` expected
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errQuoteExpected, ## ``"`` or ``'`` expected
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errEOC_Expected, ## ``*/`` expected
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errEofExpected, ## EOF expected
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errExprExpected ## expr expected
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ParserState = enum
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stateEof, stateStart, stateObject, stateArray, stateExpectArrayComma,
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stateExpectObjectComma, stateExpectColon, stateExpectValue
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JsonParser* = object of BaseLexer ## the parser object.
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a: string
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tok: TokKind
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kind: JsonEventKind
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err: JsonError
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state: seq[ParserState]
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filename: string
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JsonKindError* = object of ValueError ## raised by the ``to`` macro if the
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## JSON kind is incorrect.
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const
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errorMessages: array[JsonError, string] = [
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"no error",
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"invalid token",
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"string expected",
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"':' expected",
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"',' expected",
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"']' expected",
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"'}' expected",
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"'\"' or \"'\" expected",
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"'*/' expected",
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"EOF expected",
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"expression expected"
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]
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tokToStr: array[TokKind, string] = [
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"invalid token",
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"EOF",
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"string literal",
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"int literal",
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"float literal",
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"true",
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"false",
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"null",
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"{", "}", "[", "]", ":", ","
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]
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proc open*(my: var JsonParser, input: Stream, filename: string) =
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## initializes the parser with an input stream. `Filename` is only used
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## for nice error messages.
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lexbase.open(my, input)
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my.filename = filename
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my.state = @[stateStart]
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my.kind = jsonError
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my.a = ""
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proc close*(my: var JsonParser) {.inline.} =
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## closes the parser `my` and its associated input stream.
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lexbase.close(my)
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proc str*(my: JsonParser): string {.inline.} =
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## returns the character data for the events: ``jsonInt``, ``jsonFloat``,
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## ``jsonString``
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assert(my.kind in {jsonInt, jsonFloat, jsonString})
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return my.a
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proc getInt*(my: JsonParser): BiggestInt {.inline.} =
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## returns the number for the event: ``jsonInt``
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assert(my.kind == jsonInt)
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return parseBiggestInt(my.a)
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proc getFloat*(my: JsonParser): float {.inline.} =
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## returns the number for the event: ``jsonFloat``
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assert(my.kind == jsonFloat)
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return parseFloat(my.a)
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proc kind*(my: JsonParser): JsonEventKind {.inline.} =
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## returns the current event type for the JSON parser
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return my.kind
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proc getColumn*(my: JsonParser): int {.inline.} =
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## get the current column the parser has arrived at.
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result = getColNumber(my, my.bufpos)
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proc getLine*(my: JsonParser): int {.inline.} =
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## get the current line the parser has arrived at.
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result = my.lineNumber
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proc getFilename*(my: JsonParser): string {.inline.} =
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## get the filename of the file that the parser processes.
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result = my.filename
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proc errorMsg*(my: JsonParser): string =
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## returns a helpful error message for the event ``jsonError``
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assert(my.kind == jsonError)
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result = "$1($2, $3) Error: $4" % [
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my.filename, $getLine(my), $getColumn(my), errorMessages[my.err]]
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proc errorMsgExpected*(my: JsonParser, e: string): string =
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## returns an error message "`e` expected" in the same format as the
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## other error messages
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result = "$1($2, $3) Error: $4" % [
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my.filename, $getLine(my), $getColumn(my), e & " expected"]
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proc handleHexChar(c: char, x: var int): bool =
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result = true # Success
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case c
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of '0'..'9': x = (x shl 4) or (ord(c) - ord('0'))
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of 'a'..'f': x = (x shl 4) or (ord(c) - ord('a') + 10)
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of 'A'..'F': x = (x shl 4) or (ord(c) - ord('A') + 10)
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else: result = false # error
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proc parseEscapedUTF16(buf: cstring, pos: var int): int =
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result = 0
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#UTF-16 escape is always 4 bytes.
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for _ in 0..3:
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if handleHexChar(buf[pos], result):
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inc(pos)
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else:
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return -1
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proc parseString(my: var JsonParser): TokKind =
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result = tkString
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var pos = my.bufpos + 1
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var buf = my.buf
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while true:
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case buf[pos]
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of '\0':
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my.err = errQuoteExpected
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result = tkError
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break
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of '"':
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inc(pos)
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break
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of '\\':
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case buf[pos+1]
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of '\\', '"', '\'', '/':
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add(my.a, buf[pos+1])
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inc(pos, 2)
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of 'b':
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add(my.a, '\b')
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inc(pos, 2)
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of 'f':
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add(my.a, '\f')
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inc(pos, 2)
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of 'n':
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add(my.a, '\L')
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inc(pos, 2)
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of 'r':
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add(my.a, '\C')
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inc(pos, 2)
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of 't':
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add(my.a, '\t')
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inc(pos, 2)
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of 'u':
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inc(pos, 2)
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var r = parseEscapedUTF16(buf, pos)
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if r < 0:
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my.err = errInvalidToken
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break
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# Deal with surrogates
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if (r and 0xfc00) == 0xd800:
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if buf[pos] & buf[pos+1] != "\\u":
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my.err = errInvalidToken
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break
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inc(pos, 2)
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var s = parseEscapedUTF16(buf, pos)
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if (s and 0xfc00) == 0xdc00 and s > 0:
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r = 0x10000 + (((r - 0xd800) shl 10) or (s - 0xdc00))
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else:
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my.err = errInvalidToken
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break
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add(my.a, toUTF8(Rune(r)))
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else:
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# don't bother with the error
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add(my.a, buf[pos])
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inc(pos)
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of '\c':
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pos = lexbase.handleCR(my, pos)
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buf = my.buf
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add(my.a, '\c')
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of '\L':
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pos = lexbase.handleLF(my, pos)
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buf = my.buf
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add(my.a, '\L')
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else:
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add(my.a, buf[pos])
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inc(pos)
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my.bufpos = pos # store back
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proc skip(my: var JsonParser) =
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var pos = my.bufpos
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var buf = my.buf
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while true:
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case buf[pos]
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of '/':
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if buf[pos+1] == '/':
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# skip line comment:
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inc(pos, 2)
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while true:
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case buf[pos]
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of '\0':
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break
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of '\c':
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pos = lexbase.handleCR(my, pos)
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buf = my.buf
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break
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of '\L':
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pos = lexbase.handleLF(my, pos)
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buf = my.buf
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break
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else:
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inc(pos)
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elif buf[pos+1] == '*':
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# skip long comment:
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inc(pos, 2)
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while true:
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case buf[pos]
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of '\0':
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my.err = errEOC_Expected
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break
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of '\c':
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pos = lexbase.handleCR(my, pos)
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buf = my.buf
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of '\L':
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pos = lexbase.handleLF(my, pos)
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buf = my.buf
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of '*':
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inc(pos)
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if buf[pos] == '/':
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inc(pos)
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break
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else:
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inc(pos)
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else:
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break
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of ' ', '\t':
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inc(pos)
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of '\c':
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pos = lexbase.handleCR(my, pos)
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buf = my.buf
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of '\L':
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pos = lexbase.handleLF(my, pos)
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buf = my.buf
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else:
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break
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my.bufpos = pos
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proc parseNumber(my: var JsonParser) =
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var pos = my.bufpos
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var buf = my.buf
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if buf[pos] == '-':
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add(my.a, '-')
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inc(pos)
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if buf[pos] == '.':
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add(my.a, "0.")
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inc(pos)
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else:
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while buf[pos] in Digits:
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add(my.a, buf[pos])
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inc(pos)
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if buf[pos] == '.':
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add(my.a, '.')
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inc(pos)
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# digits after the dot:
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while buf[pos] in Digits:
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add(my.a, buf[pos])
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inc(pos)
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if buf[pos] in {'E', 'e'}:
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add(my.a, buf[pos])
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inc(pos)
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if buf[pos] in {'+', '-'}:
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add(my.a, buf[pos])
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inc(pos)
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while buf[pos] in Digits:
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add(my.a, buf[pos])
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inc(pos)
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my.bufpos = pos
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proc parseName(my: var JsonParser) =
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var pos = my.bufpos
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var buf = my.buf
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if buf[pos] in IdentStartChars:
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while buf[pos] in IdentChars:
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add(my.a, buf[pos])
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inc(pos)
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my.bufpos = pos
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proc getTok(my: var JsonParser): TokKind =
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setLen(my.a, 0)
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skip(my) # skip whitespace, comments
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case my.buf[my.bufpos]
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of '-', '.', '0'..'9':
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parseNumber(my)
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if {'.', 'e', 'E'} in my.a:
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result = tkFloat
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else:
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result = tkInt
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of '"':
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result = parseString(my)
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of '[':
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inc(my.bufpos)
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result = tkBracketLe
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of '{':
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inc(my.bufpos)
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result = tkCurlyLe
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of ']':
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inc(my.bufpos)
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result = tkBracketRi
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of '}':
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inc(my.bufpos)
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result = tkCurlyRi
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of ',':
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inc(my.bufpos)
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result = tkComma
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of ':':
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inc(my.bufpos)
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result = tkColon
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of '\0':
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result = tkEof
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of 'a'..'z', 'A'..'Z', '_':
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parseName(my)
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case my.a
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of "null": result = tkNull
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of "true": result = tkTrue
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of "false": result = tkFalse
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else: result = tkError
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else:
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inc(my.bufpos)
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result = tkError
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my.tok = result
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proc next*(my: var JsonParser) =
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## retrieves the first/next event. This controls the parser.
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var tk = getTok(my)
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var i = my.state.len-1
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# the following code is a state machine. If we had proper coroutines,
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# the code could be much simpler.
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case my.state[i]
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of stateEof:
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if tk == tkEof:
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my.kind = jsonEof
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else:
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my.kind = jsonError
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my.err = errEofExpected
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of stateStart:
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# tokens allowed?
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case tk
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of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
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my.state[i] = stateEof # expect EOF next!
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my.kind = JsonEventKind(ord(tk))
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of tkBracketLe:
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my.state.add(stateArray) # we expect any
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my.kind = jsonArrayStart
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of tkCurlyLe:
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my.state.add(stateObject)
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my.kind = jsonObjectStart
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of tkEof:
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my.kind = jsonEof
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else:
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my.kind = jsonError
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my.err = errEofExpected
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of stateObject:
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case tk
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of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
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my.state.add(stateExpectColon)
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my.kind = JsonEventKind(ord(tk))
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of tkBracketLe:
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my.state.add(stateExpectColon)
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my.state.add(stateArray)
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my.kind = jsonArrayStart
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of tkCurlyLe:
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my.state.add(stateExpectColon)
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my.state.add(stateObject)
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my.kind = jsonObjectStart
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of tkCurlyRi:
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my.kind = jsonObjectEnd
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discard my.state.pop()
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else:
|
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my.kind = jsonError
|
||||
my.err = errCurlyRiExpected
|
||||
of stateArray:
|
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case tk
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of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
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my.state.add(stateExpectArrayComma) # expect value next!
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my.kind = JsonEventKind(ord(tk))
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of tkBracketLe:
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my.state.add(stateExpectArrayComma)
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my.state.add(stateArray)
|
||||
my.kind = jsonArrayStart
|
||||
of tkCurlyLe:
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my.state.add(stateExpectArrayComma)
|
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my.state.add(stateObject)
|
||||
my.kind = jsonObjectStart
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||||
of tkBracketRi:
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my.kind = jsonArrayEnd
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||||
discard my.state.pop()
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else:
|
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my.kind = jsonError
|
||||
my.err = errBracketRiExpected
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||||
of stateExpectArrayComma:
|
||||
case tk
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||||
of tkComma:
|
||||
discard my.state.pop()
|
||||
next(my)
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||||
of tkBracketRi:
|
||||
my.kind = jsonArrayEnd
|
||||
discard my.state.pop() # pop stateExpectArrayComma
|
||||
discard my.state.pop() # pop stateArray
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errBracketRiExpected
|
||||
of stateExpectObjectComma:
|
||||
case tk
|
||||
of tkComma:
|
||||
discard my.state.pop()
|
||||
next(my)
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||||
of tkCurlyRi:
|
||||
my.kind = jsonObjectEnd
|
||||
discard my.state.pop() # pop stateExpectObjectComma
|
||||
discard my.state.pop() # pop stateObject
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errCurlyRiExpected
|
||||
of stateExpectColon:
|
||||
case tk
|
||||
of tkColon:
|
||||
my.state[i] = stateExpectValue
|
||||
next(my)
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errColonExpected
|
||||
of stateExpectValue:
|
||||
case tk
|
||||
of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
|
||||
my.state[i] = stateExpectObjectComma
|
||||
my.kind = JsonEventKind(ord(tk))
|
||||
of tkBracketLe:
|
||||
my.state[i] = stateExpectObjectComma
|
||||
my.state.add(stateArray)
|
||||
my.kind = jsonArrayStart
|
||||
of tkCurlyLe:
|
||||
my.state[i] = stateExpectObjectComma
|
||||
my.state.add(stateObject)
|
||||
my.kind = jsonObjectStart
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errExprExpected
|
||||
|
||||
|
||||
# ------------- higher level interface ---------------------------------------
|
||||
|
||||
type
|
||||
JsonNodeKind* = enum ## possible JSON node types
|
||||
JNull,
|
||||
@@ -617,12 +132,6 @@ type
|
||||
of JArray:
|
||||
elems*: seq[JsonNode]
|
||||
|
||||
JsonParsingError* = object of ValueError ## is raised for a JSON error
|
||||
|
||||
proc raiseParseErr*(p: JsonParser, msg: string) {.noinline, noreturn.} =
|
||||
## raises an `EJsonParsingError` exception.
|
||||
raise newException(JsonParsingError, errorMsgExpected(p, msg))
|
||||
|
||||
proc newJString*(s: string): JsonNode =
|
||||
## Creates a new `JString JsonNode`.
|
||||
new(result)
|
||||
@@ -1194,10 +703,6 @@ iterator mpairs*(node: var JsonNode): tuple[key: string, val: var JsonNode] =
|
||||
for key, val in mpairs(node.fields):
|
||||
yield (key, val)
|
||||
|
||||
proc eat(p: var JsonParser, tok: TokKind) =
|
||||
if p.tok == tok: discard getTok(p)
|
||||
else: raiseParseErr(p, tokToStr[tok])
|
||||
|
||||
proc parseJson(p: var JsonParser): JsonNode =
|
||||
## Parses JSON from a JSON Parser `p`.
|
||||
case p.tok
|
||||
@@ -1253,10 +758,12 @@ when not defined(js):
|
||||
## If `s` contains extra data, it will raise `JsonParsingError`.
|
||||
var p: JsonParser
|
||||
p.open(s, filename)
|
||||
defer: p.close()
|
||||
discard getTok(p) # read first token
|
||||
result = p.parseJson()
|
||||
eat(p, tkEof) # check if there is no extra data
|
||||
try:
|
||||
discard getTok(p) # read first token
|
||||
result = p.parseJson()
|
||||
eat(p, tkEof) # check if there is no extra data
|
||||
finally:
|
||||
p.close()
|
||||
|
||||
proc parseJson*(buffer: string): JsonNode =
|
||||
## Parses JSON from `buffer`.
|
||||
|
||||
535
lib/pure/parsejson.nim
Normal file
535
lib/pure/parsejson.nim
Normal file
@@ -0,0 +1,535 @@
|
||||
#
|
||||
#
|
||||
# Nim's Runtime Library
|
||||
# (c) Copyright 2018 Nim contributors
|
||||
#
|
||||
# See the file "copying.txt", included in this
|
||||
# distribution, for details about the copyright.
|
||||
#
|
||||
|
||||
## This module implements a json parser. It is used
|
||||
## and exported by the ``json`` standard library
|
||||
## module, but can also be used in its own right.
|
||||
|
||||
import
|
||||
strutils, lexbase, streams, unicode
|
||||
|
||||
type
|
||||
JsonEventKind* = enum ## enumeration of all events that may occur when parsing
|
||||
jsonError, ## an error occurred during parsing
|
||||
jsonEof, ## end of file reached
|
||||
jsonString, ## a string literal
|
||||
jsonInt, ## an integer literal
|
||||
jsonFloat, ## a float literal
|
||||
jsonTrue, ## the value ``true``
|
||||
jsonFalse, ## the value ``false``
|
||||
jsonNull, ## the value ``null``
|
||||
jsonObjectStart, ## start of an object: the ``{`` token
|
||||
jsonObjectEnd, ## end of an object: the ``}`` token
|
||||
jsonArrayStart, ## start of an array: the ``[`` token
|
||||
jsonArrayEnd ## start of an array: the ``]`` token
|
||||
|
||||
TokKind* = enum # must be synchronized with TJsonEventKind!
|
||||
tkError,
|
||||
tkEof,
|
||||
tkString,
|
||||
tkInt,
|
||||
tkFloat,
|
||||
tkTrue,
|
||||
tkFalse,
|
||||
tkNull,
|
||||
tkCurlyLe,
|
||||
tkCurlyRi,
|
||||
tkBracketLe,
|
||||
tkBracketRi,
|
||||
tkColon,
|
||||
tkComma
|
||||
|
||||
JsonError* = enum ## enumeration that lists all errors that can occur
|
||||
errNone, ## no error
|
||||
errInvalidToken, ## invalid token
|
||||
errStringExpected, ## string expected
|
||||
errColonExpected, ## ``:`` expected
|
||||
errCommaExpected, ## ``,`` expected
|
||||
errBracketRiExpected, ## ``]`` expected
|
||||
errCurlyRiExpected, ## ``}`` expected
|
||||
errQuoteExpected, ## ``"`` or ``'`` expected
|
||||
errEOC_Expected, ## ``*/`` expected
|
||||
errEofExpected, ## EOF expected
|
||||
errExprExpected ## expr expected
|
||||
|
||||
ParserState = enum
|
||||
stateEof, stateStart, stateObject, stateArray, stateExpectArrayComma,
|
||||
stateExpectObjectComma, stateExpectColon, stateExpectValue
|
||||
|
||||
JsonParser* = object of BaseLexer ## the parser object.
|
||||
a*: string
|
||||
tok*: TokKind
|
||||
kind: JsonEventKind
|
||||
err: JsonError
|
||||
state: seq[ParserState]
|
||||
filename: string
|
||||
rawStringLiterals: bool
|
||||
|
||||
JsonKindError* = object of ValueError ## raised by the ``to`` macro if the
|
||||
## JSON kind is incorrect.
|
||||
JsonParsingError* = object of ValueError ## is raised for a JSON error
|
||||
|
||||
const
|
||||
errorMessages*: array[JsonError, string] = [
|
||||
"no error",
|
||||
"invalid token",
|
||||
"string expected",
|
||||
"':' expected",
|
||||
"',' expected",
|
||||
"']' expected",
|
||||
"'}' expected",
|
||||
"'\"' or \"'\" expected",
|
||||
"'*/' expected",
|
||||
"EOF expected",
|
||||
"expression expected"
|
||||
]
|
||||
tokToStr: array[TokKind, string] = [
|
||||
"invalid token",
|
||||
"EOF",
|
||||
"string literal",
|
||||
"int literal",
|
||||
"float literal",
|
||||
"true",
|
||||
"false",
|
||||
"null",
|
||||
"{", "}", "[", "]", ":", ","
|
||||
]
|
||||
|
||||
proc open*(my: var JsonParser, input: Stream, filename: string;
|
||||
rawStringLiterals = false) =
|
||||
## initializes the parser with an input stream. `Filename` is only used
|
||||
## for nice error messages. If `rawStringLiterals` is true, string literals
|
||||
## are kepts with their surrounding quotes and escape sequences in them are
|
||||
## left untouched too.
|
||||
lexbase.open(my, input)
|
||||
my.filename = filename
|
||||
my.state = @[stateStart]
|
||||
my.kind = jsonError
|
||||
my.a = ""
|
||||
my.rawStringLiterals = rawStringLiterals
|
||||
|
||||
proc close*(my: var JsonParser) {.inline.} =
|
||||
## closes the parser `my` and its associated input stream.
|
||||
lexbase.close(my)
|
||||
|
||||
proc str*(my: JsonParser): string {.inline.} =
|
||||
## returns the character data for the events: ``jsonInt``, ``jsonFloat``,
|
||||
## ``jsonString``
|
||||
assert(my.kind in {jsonInt, jsonFloat, jsonString})
|
||||
return my.a
|
||||
|
||||
proc getInt*(my: JsonParser): BiggestInt {.inline.} =
|
||||
## returns the number for the event: ``jsonInt``
|
||||
assert(my.kind == jsonInt)
|
||||
return parseBiggestInt(my.a)
|
||||
|
||||
proc getFloat*(my: JsonParser): float {.inline.} =
|
||||
## returns the number for the event: ``jsonFloat``
|
||||
assert(my.kind == jsonFloat)
|
||||
return parseFloat(my.a)
|
||||
|
||||
proc kind*(my: JsonParser): JsonEventKind {.inline.} =
|
||||
## returns the current event type for the JSON parser
|
||||
return my.kind
|
||||
|
||||
proc getColumn*(my: JsonParser): int {.inline.} =
|
||||
## get the current column the parser has arrived at.
|
||||
result = getColNumber(my, my.bufpos)
|
||||
|
||||
proc getLine*(my: JsonParser): int {.inline.} =
|
||||
## get the current line the parser has arrived at.
|
||||
result = my.lineNumber
|
||||
|
||||
proc getFilename*(my: JsonParser): string {.inline.} =
|
||||
## get the filename of the file that the parser processes.
|
||||
result = my.filename
|
||||
|
||||
proc errorMsg*(my: JsonParser): string =
|
||||
## returns a helpful error message for the event ``jsonError``
|
||||
assert(my.kind == jsonError)
|
||||
result = "$1($2, $3) Error: $4" % [
|
||||
my.filename, $getLine(my), $getColumn(my), errorMessages[my.err]]
|
||||
|
||||
proc errorMsgExpected*(my: JsonParser, e: string): string =
|
||||
## returns an error message "`e` expected" in the same format as the
|
||||
## other error messages
|
||||
result = "$1($2, $3) Error: $4" % [
|
||||
my.filename, $getLine(my), $getColumn(my), e & " expected"]
|
||||
|
||||
proc handleHexChar(c: char, x: var int): bool =
|
||||
result = true # Success
|
||||
case c
|
||||
of '0'..'9': x = (x shl 4) or (ord(c) - ord('0'))
|
||||
of 'a'..'f': x = (x shl 4) or (ord(c) - ord('a') + 10)
|
||||
of 'A'..'F': x = (x shl 4) or (ord(c) - ord('A') + 10)
|
||||
else: result = false # error
|
||||
|
||||
proc parseEscapedUTF16*(buf: cstring, pos: var int): int =
|
||||
result = 0
|
||||
#UTF-16 escape is always 4 bytes.
|
||||
for _ in 0..3:
|
||||
if handleHexChar(buf[pos], result):
|
||||
inc(pos)
|
||||
else:
|
||||
return -1
|
||||
|
||||
proc parseString(my: var JsonParser): TokKind =
|
||||
result = tkString
|
||||
var pos = my.bufpos + 1
|
||||
var buf = my.buf
|
||||
if my.rawStringLiterals:
|
||||
add(my.a, '"')
|
||||
while true:
|
||||
case buf[pos]
|
||||
of '\0':
|
||||
my.err = errQuoteExpected
|
||||
result = tkError
|
||||
break
|
||||
of '"':
|
||||
if my.rawStringLiterals:
|
||||
add(my.a, '"')
|
||||
inc(pos)
|
||||
break
|
||||
of '\\':
|
||||
if my.rawStringLiterals:
|
||||
add(my.a, '\\')
|
||||
case buf[pos+1]
|
||||
of '\\', '"', '\'', '/':
|
||||
add(my.a, buf[pos+1])
|
||||
inc(pos, 2)
|
||||
of 'b':
|
||||
add(my.a, '\b')
|
||||
inc(pos, 2)
|
||||
of 'f':
|
||||
add(my.a, '\f')
|
||||
inc(pos, 2)
|
||||
of 'n':
|
||||
add(my.a, '\L')
|
||||
inc(pos, 2)
|
||||
of 'r':
|
||||
add(my.a, '\C')
|
||||
inc(pos, 2)
|
||||
of 't':
|
||||
add(my.a, '\t')
|
||||
inc(pos, 2)
|
||||
of 'u':
|
||||
if my.rawStringLiterals:
|
||||
add(my.a, 'u')
|
||||
inc(pos, 2)
|
||||
var pos2 = pos
|
||||
var r = parseEscapedUTF16(buf, pos)
|
||||
if r < 0:
|
||||
my.err = errInvalidToken
|
||||
break
|
||||
# Deal with surrogates
|
||||
if (r and 0xfc00) == 0xd800:
|
||||
if buf[pos] != '\\' or buf[pos+1] != 'u':
|
||||
my.err = errInvalidToken
|
||||
break
|
||||
inc(pos, 2)
|
||||
var s = parseEscapedUTF16(buf, pos)
|
||||
if (s and 0xfc00) == 0xdc00 and s > 0:
|
||||
r = 0x10000 + (((r - 0xd800) shl 10) or (s - 0xdc00))
|
||||
else:
|
||||
my.err = errInvalidToken
|
||||
break
|
||||
if my.rawStringLiterals:
|
||||
let length = pos - pos2
|
||||
for i in 1 .. length:
|
||||
if buf[pos2] in {'0'..'9', 'A'..'F', 'a'..'f'}:
|
||||
add(my.a, buf[pos2])
|
||||
inc pos2
|
||||
else:
|
||||
break
|
||||
else:
|
||||
add(my.a, toUTF8(Rune(r)))
|
||||
else:
|
||||
# don't bother with the error
|
||||
add(my.a, buf[pos])
|
||||
inc(pos)
|
||||
of '\c':
|
||||
pos = lexbase.handleCR(my, pos)
|
||||
buf = my.buf
|
||||
add(my.a, '\c')
|
||||
of '\L':
|
||||
pos = lexbase.handleLF(my, pos)
|
||||
buf = my.buf
|
||||
add(my.a, '\L')
|
||||
else:
|
||||
add(my.a, buf[pos])
|
||||
inc(pos)
|
||||
my.bufpos = pos # store back
|
||||
|
||||
proc skip(my: var JsonParser) =
|
||||
var pos = my.bufpos
|
||||
var buf = my.buf
|
||||
while true:
|
||||
case buf[pos]
|
||||
of '/':
|
||||
if buf[pos+1] == '/':
|
||||
# skip line comment:
|
||||
inc(pos, 2)
|
||||
while true:
|
||||
case buf[pos]
|
||||
of '\0':
|
||||
break
|
||||
of '\c':
|
||||
pos = lexbase.handleCR(my, pos)
|
||||
buf = my.buf
|
||||
break
|
||||
of '\L':
|
||||
pos = lexbase.handleLF(my, pos)
|
||||
buf = my.buf
|
||||
break
|
||||
else:
|
||||
inc(pos)
|
||||
elif buf[pos+1] == '*':
|
||||
# skip long comment:
|
||||
inc(pos, 2)
|
||||
while true:
|
||||
case buf[pos]
|
||||
of '\0':
|
||||
my.err = errEOC_Expected
|
||||
break
|
||||
of '\c':
|
||||
pos = lexbase.handleCR(my, pos)
|
||||
buf = my.buf
|
||||
of '\L':
|
||||
pos = lexbase.handleLF(my, pos)
|
||||
buf = my.buf
|
||||
of '*':
|
||||
inc(pos)
|
||||
if buf[pos] == '/':
|
||||
inc(pos)
|
||||
break
|
||||
else:
|
||||
inc(pos)
|
||||
else:
|
||||
break
|
||||
of ' ', '\t':
|
||||
inc(pos)
|
||||
of '\c':
|
||||
pos = lexbase.handleCR(my, pos)
|
||||
buf = my.buf
|
||||
of '\L':
|
||||
pos = lexbase.handleLF(my, pos)
|
||||
buf = my.buf
|
||||
else:
|
||||
break
|
||||
my.bufpos = pos
|
||||
|
||||
proc parseNumber(my: var JsonParser) =
|
||||
var pos = my.bufpos
|
||||
var buf = my.buf
|
||||
if buf[pos] == '-':
|
||||
add(my.a, '-')
|
||||
inc(pos)
|
||||
if buf[pos] == '.':
|
||||
add(my.a, "0.")
|
||||
inc(pos)
|
||||
else:
|
||||
while buf[pos] in Digits:
|
||||
add(my.a, buf[pos])
|
||||
inc(pos)
|
||||
if buf[pos] == '.':
|
||||
add(my.a, '.')
|
||||
inc(pos)
|
||||
# digits after the dot:
|
||||
while buf[pos] in Digits:
|
||||
add(my.a, buf[pos])
|
||||
inc(pos)
|
||||
if buf[pos] in {'E', 'e'}:
|
||||
add(my.a, buf[pos])
|
||||
inc(pos)
|
||||
if buf[pos] in {'+', '-'}:
|
||||
add(my.a, buf[pos])
|
||||
inc(pos)
|
||||
while buf[pos] in Digits:
|
||||
add(my.a, buf[pos])
|
||||
inc(pos)
|
||||
my.bufpos = pos
|
||||
|
||||
proc parseName(my: var JsonParser) =
|
||||
var pos = my.bufpos
|
||||
var buf = my.buf
|
||||
if buf[pos] in IdentStartChars:
|
||||
while buf[pos] in IdentChars:
|
||||
add(my.a, buf[pos])
|
||||
inc(pos)
|
||||
my.bufpos = pos
|
||||
|
||||
proc getTok*(my: var JsonParser): TokKind =
|
||||
setLen(my.a, 0)
|
||||
skip(my) # skip whitespace, comments
|
||||
case my.buf[my.bufpos]
|
||||
of '-', '.', '0'..'9':
|
||||
parseNumber(my)
|
||||
if {'.', 'e', 'E'} in my.a:
|
||||
result = tkFloat
|
||||
else:
|
||||
result = tkInt
|
||||
of '"':
|
||||
result = parseString(my)
|
||||
of '[':
|
||||
inc(my.bufpos)
|
||||
result = tkBracketLe
|
||||
of '{':
|
||||
inc(my.bufpos)
|
||||
result = tkCurlyLe
|
||||
of ']':
|
||||
inc(my.bufpos)
|
||||
result = tkBracketRi
|
||||
of '}':
|
||||
inc(my.bufpos)
|
||||
result = tkCurlyRi
|
||||
of ',':
|
||||
inc(my.bufpos)
|
||||
result = tkComma
|
||||
of ':':
|
||||
inc(my.bufpos)
|
||||
result = tkColon
|
||||
of '\0':
|
||||
result = tkEof
|
||||
of 'a'..'z', 'A'..'Z', '_':
|
||||
parseName(my)
|
||||
case my.a
|
||||
of "null": result = tkNull
|
||||
of "true": result = tkTrue
|
||||
of "false": result = tkFalse
|
||||
else: result = tkError
|
||||
else:
|
||||
inc(my.bufpos)
|
||||
result = tkError
|
||||
my.tok = result
|
||||
|
||||
|
||||
proc next*(my: var JsonParser) =
|
||||
## retrieves the first/next event. This controls the parser.
|
||||
var tk = getTok(my)
|
||||
var i = my.state.len-1
|
||||
# the following code is a state machine. If we had proper coroutines,
|
||||
# the code could be much simpler.
|
||||
case my.state[i]
|
||||
of stateEof:
|
||||
if tk == tkEof:
|
||||
my.kind = jsonEof
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errEofExpected
|
||||
of stateStart:
|
||||
# tokens allowed?
|
||||
case tk
|
||||
of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
|
||||
my.state[i] = stateEof # expect EOF next!
|
||||
my.kind = JsonEventKind(ord(tk))
|
||||
of tkBracketLe:
|
||||
my.state.add(stateArray) # we expect any
|
||||
my.kind = jsonArrayStart
|
||||
of tkCurlyLe:
|
||||
my.state.add(stateObject)
|
||||
my.kind = jsonObjectStart
|
||||
of tkEof:
|
||||
my.kind = jsonEof
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errEofExpected
|
||||
of stateObject:
|
||||
case tk
|
||||
of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
|
||||
my.state.add(stateExpectColon)
|
||||
my.kind = JsonEventKind(ord(tk))
|
||||
of tkBracketLe:
|
||||
my.state.add(stateExpectColon)
|
||||
my.state.add(stateArray)
|
||||
my.kind = jsonArrayStart
|
||||
of tkCurlyLe:
|
||||
my.state.add(stateExpectColon)
|
||||
my.state.add(stateObject)
|
||||
my.kind = jsonObjectStart
|
||||
of tkCurlyRi:
|
||||
my.kind = jsonObjectEnd
|
||||
discard my.state.pop()
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errCurlyRiExpected
|
||||
of stateArray:
|
||||
case tk
|
||||
of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
|
||||
my.state.add(stateExpectArrayComma) # expect value next!
|
||||
my.kind = JsonEventKind(ord(tk))
|
||||
of tkBracketLe:
|
||||
my.state.add(stateExpectArrayComma)
|
||||
my.state.add(stateArray)
|
||||
my.kind = jsonArrayStart
|
||||
of tkCurlyLe:
|
||||
my.state.add(stateExpectArrayComma)
|
||||
my.state.add(stateObject)
|
||||
my.kind = jsonObjectStart
|
||||
of tkBracketRi:
|
||||
my.kind = jsonArrayEnd
|
||||
discard my.state.pop()
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errBracketRiExpected
|
||||
of stateExpectArrayComma:
|
||||
case tk
|
||||
of tkComma:
|
||||
discard my.state.pop()
|
||||
next(my)
|
||||
of tkBracketRi:
|
||||
my.kind = jsonArrayEnd
|
||||
discard my.state.pop() # pop stateExpectArrayComma
|
||||
discard my.state.pop() # pop stateArray
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errBracketRiExpected
|
||||
of stateExpectObjectComma:
|
||||
case tk
|
||||
of tkComma:
|
||||
discard my.state.pop()
|
||||
next(my)
|
||||
of tkCurlyRi:
|
||||
my.kind = jsonObjectEnd
|
||||
discard my.state.pop() # pop stateExpectObjectComma
|
||||
discard my.state.pop() # pop stateObject
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errCurlyRiExpected
|
||||
of stateExpectColon:
|
||||
case tk
|
||||
of tkColon:
|
||||
my.state[i] = stateExpectValue
|
||||
next(my)
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errColonExpected
|
||||
of stateExpectValue:
|
||||
case tk
|
||||
of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
|
||||
my.state[i] = stateExpectObjectComma
|
||||
my.kind = JsonEventKind(ord(tk))
|
||||
of tkBracketLe:
|
||||
my.state[i] = stateExpectObjectComma
|
||||
my.state.add(stateArray)
|
||||
my.kind = jsonArrayStart
|
||||
of tkCurlyLe:
|
||||
my.state[i] = stateExpectObjectComma
|
||||
my.state.add(stateObject)
|
||||
my.kind = jsonObjectStart
|
||||
else:
|
||||
my.kind = jsonError
|
||||
my.err = errExprExpected
|
||||
|
||||
proc raiseParseErr*(p: JsonParser, msg: string) {.noinline, noreturn.} =
|
||||
## raises an `EJsonParsingError` exception.
|
||||
raise newException(JsonParsingError, errorMsgExpected(p, msg))
|
||||
|
||||
proc eat*(p: var JsonParser, tok: TokKind) =
|
||||
if p.tok == tok: discard getTok(p)
|
||||
else: raiseParseErr(p, tokToStr[tok])
|
||||
Reference in New Issue
Block a user