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Diffstat (limited to 'lib/pure/parsejson.nim')
| -rwxr-xr-x | lib/pure/parsejson.nim | 484 |
1 files changed, 0 insertions, 484 deletions
diff --git a/lib/pure/parsejson.nim b/lib/pure/parsejson.nim deleted file mode 100755 index 0fd2a9f01..000000000 --- a/lib/pure/parsejson.nim +++ /dev/null @@ -1,484 +0,0 @@ -# -# -# Nimrod's Runtime Library -# (c) Copyright 2010 Andreas Rumpf -# -# See the file "copying.txt", included in this -# distribution, for details about the copyright. -# - -## This module implements a simple high performance `JSON`:idx: -## parser. JSON (JavaScript Object Notation) is a lightweight -## data-interchange format that is easy for humans to read and write -## (unlike XML). It is easy for machines to parse and generate. -## JSON is based on a subset of the JavaScript Programming Language, -## Standard ECMA-262 3rd Edition - December 1999. - -import - hashes, strutils, lexbase, streams, unicode - -type - TJsonEventKind* = enum ## enumation of all events that may occur when parsing - jsonError, ## an error ocurred during parsing - jsonEof, ## end of file reached - jsonString, ## a string literal - jsonNumber, ## a number 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 - - TTokKind = enum # must be synchronized with TJsonEventKind! - tkError, - tkEof, - tkString, - tkNumber, - tkTrue, - tkFalse, - tkNull, - tkCurlyLe, - tkCurlyRi, - tkBracketLe, - tkBracketRi, - tkColon, - tkComma - - TJsonError* = 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 - - TParserState = enum - stateEof, stateStart, stateObject, stateArray, stateExpectArrayComma, - stateExpectObjectComma, stateExpectColon, stateExpectValue - - TJsonParser* = object of TBaseLexer ## the parser object. - a: string - kind: TJsonEventKind - err: TJsonError - state: seq[TParserState] - filename: string - -const - errorMessages: array [TJsonError, string] = [ - "no error", - "invalid token", - "string expected", - "':' expected", - "',' expected", - "']' expected", - "'}' expected", - "'\"' or \"'\" expected", - "'*/' expected", - "EOF expected", - "expression expected" - ] - -proc open*(my: var TJsonParser, input: PStream, filename: string) = - ## initializes the parser with an input stream. `Filename` is only used - ## for nice error messages. - lexbase.open(my, input) - my.filename = filename - my.state = @[stateStart] - my.kind = jsonError - my.a = "" - -proc close*(my: var TJsonParser) {.inline.} = - ## closes the parser `my` and its associated input stream. - lexbase.close(my) - -proc str*(my: TJsonParser): string {.inline.} = - ## returns the character data for the events: ``jsonNumber``, - ## ``jsonString`` - assert(my.kind in {jsonNumber, jsonString}) - return my.a - -proc number*(my: TJsonParser): float {.inline.} = - ## returns the number for the event: ``jsonNumber`` - assert(my.kind == jsonNumber) - return parseFloat(my.a) - -proc kind*(my: TJsonParser): TJsonEventKind {.inline.} = - ## returns the current event type for the JSON parser - return my.kind - -proc getColumn*(my: TJsonParser): int {.inline.} = - ## get the current column the parser has arrived at. - result = getColNumber(my, my.bufPos) - -proc getLine*(my: TJsonParser): int {.inline.} = - ## get the current line the parser has arrived at. - result = my.linenumber - -proc getFilename*(my: TJsonParser): string {.inline.} = - ## get the filename of the file that the parser processes. - result = my.filename - -proc errorMsg*(my: TJsonParser): 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: TJsonParser, 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 parseString(my: var TJsonParser): TTokKind = - result = tkString - var pos = my.bufpos + 1 - var buf = my.buf - while true: - case buf[pos] - of '\0': - my.err = errQuoteExpected - result = tkError - break - of '"': - inc(pos) - break - of '\\': - 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': - inc(pos, 2) - var r: int - if handleHexChar(buf[pos], r): inc(pos) - if handleHexChar(buf[pos], r): inc(pos) - if handleHexChar(buf[pos], r): inc(pos) - if handleHexChar(buf[pos], r): inc(pos) - add(my.a, toUTF8(TRune(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 TJsonParser) = - 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 TJsonParser) = - 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 TJsonParser) = - 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 TJsonParser): TTokKind = - setLen(my.a, 0) - skip(my) # skip whitespace, comments - case my.buf[my.bufpos] - of '-', '.', '0'..'9': - parseNumber(my) - result = tkNumber - 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 - -proc next*(my: var TJsonParser) = - ## 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, tkNumber, tkTrue, tkFalse, tkNull: - my.state[i] = stateEof # expect EOF next! - my.kind = TJsonEventKind(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, tkNumber, tkTrue, tkFalse, tkNull: - my.state.add(stateExpectColon) - my.kind = TJsonEventKind(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, tkNumber, tkTrue, tkFalse, tkNull: - my.state.add(stateExpectArrayComma) # expect value next! - my.kind = TJsonEventKind(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, tkNumber, tkTrue, tkFalse, tkNull: - my.state[i] = stateExpectObjectComma - my.kind = TJsonEventKind(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 - -when isMainModule: - import os - var s = newFileStream(ParamStr(1), fmRead) - if s == nil: quit("cannot open the file" & ParamStr(1)) - var x: TJsonParser - open(x, s, ParamStr(1)) - while true: - next(x) - case x.kind - of jsonError: - Echo(x.errorMsg()) - break - of jsonEof: break - of jsonString, jsonNumber: echo(x.str) - of jsonTrue: Echo("!TRUE") - of jsonFalse: Echo("!FALSE") - of jsonNull: Echo("!NULL") - of jsonObjectStart: Echo("{") - of jsonObjectEnd: Echo("}") - of jsonArrayStart: Echo("[") - of jsonArrayEnd: Echo("]") - - close(x) - |