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.


JsonEventKind = enum
  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               ## end of an array: the ``]`` token
enumeration of all events that may occur when parsing   Source Edit
TokKind = enum
  tkError, tkEof, tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull, tkCurlyLe,
  tkCurlyRi, tkBracketLe, tkBracketRi, tkColon, tkComma
  Source Edit
JsonError = enum
  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
enumeration that lists all errors that can occur   Source Edit
JsonParser = object of BaseLexer
  a*: string
  tok*: TokKind
  kind: JsonEventKind
  err: JsonError
  state: seq[ParserState]
  filename: string
  rawStringLiterals: bool
the parser object.   Source Edit
JsonKindError = object of ValueError
raised by the to macro if the JSON kind is incorrect.   Source Edit
JsonParsingError = object of ValueError
is raised for a JSON error   Source Edit


errorMessages: array[JsonError, string] = ["no error", "invalid token",
    "string expected", "\':\' expected", "\',\' expected", "\']\' expected",
    "\'}\' expected", "\'\"\' or \"\'\" expected", "\'*/\' expected",
    "EOF expected", "expression expected"]
  Source Edit


proc open(my: var JsonParser; input: Stream; filename: string;
          rawStringLiterals = false) {...}{.raises: [IOError, OSError],
                                       tags: [ReadIOEffect].}
initializes the parser with an input stream. Filename is only used for nice error messages. If rawStringLiterals is true, string literals are kept with their surrounding quotes and escape sequences in them are left untouched too.   Source Edit
proc close(my: var JsonParser) {...}{.inline, raises: [Exception, IOError, OSError],
                                 tags: [WriteIOEffect].}
closes the parser my and its associated input stream.   Source Edit
proc str(my: JsonParser): string {...}{.inline, raises: [], tags: [].}
returns the character data for the events: jsonInt, jsonFloat, jsonString   Source Edit
proc getInt(my: JsonParser): BiggestInt {...}{.inline, raises: [ValueError], tags: [].}
returns the number for the event: jsonInt   Source Edit
proc getFloat(my: JsonParser): float {...}{.inline, raises: [ValueError], tags: [].}
returns the number for the event: jsonFloat   Source Edit
proc kind(my: JsonParser): JsonEventKind {...}{.inline, raises: [], tags: [].}
returns the current event type for the JSON parser   Source Edit
proc getColumn(my: JsonParser): int {...}{.inline, raises: [], tags: [].}
get the current column the parser has arrived at.   Source Edit
proc getLine(my: JsonParser): int {...}{.inline, raises: [], tags: [].}
get the current line the parser has arrived at.   Source Edit
proc getFilename(my: JsonParser): string {...}{.inline, raises: [], tags: [].}
get the filename of the file that the parser processes.   Source Edit
proc errorMsg(my: JsonParser): string {...}{.raises: [ValueError], tags: [].}
returns a helpful error message for the event jsonError   Source Edit
proc errorMsgExpected(my: JsonParser; e: string): string {...}{.raises: [ValueError],
    tags: [].}
returns an error message "e expected" in the same format as the other error messages   Source Edit
proc parseEscapedUTF16(buf: cstring; pos: var int): int {...}{.raises: [], tags: [].}
  Source Edit
proc getTok(my: var JsonParser): TokKind {...}{.raises: [IOError, OSError],
    tags: [ReadIOEffect].}
  Source Edit
proc next(my: var JsonParser) {...}{.raises: [IOError, OSError], tags: [ReadIOEffect].}
retrieves the first/next event. This controls the parser.   Source Edit
proc raiseParseErr(p: JsonParser; msg: string) {...}{.noinline, noreturn,
    raises: [JsonParsingError, ValueError], tags: [].}
raises an EJsonParsingError exception.   Source Edit
proc eat(p: var JsonParser; tok: TokKind) {...}{.
    raises: [IOError, OSError, JsonParsingError, ValueError],
    tags: [ReadIOEffect].}
  Source Edit