diff options
author | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2015-05-01 16:13:57 +0200 |
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committer | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2015-05-01 16:13:57 +0200 |
commit | 094535c010320967639e8e86f974d878e80baa72 (patch) | |
tree | efc3094b20355dcbeebb2c4ece4fcfc69bffedb5 /yajl/yajl_lex.c | |
parent | c07d0c2d2f6f7b0eb6e92cc6204bf05037957e82 (diff) |
Imported Upstream version 1.7.0upstream/1.7.0
Diffstat (limited to 'yajl/yajl_lex.c')
-rw-r--r-- | yajl/yajl_lex.c | 778 |
1 files changed, 778 insertions, 0 deletions
diff --git a/yajl/yajl_lex.c b/yajl/yajl_lex.c new file mode 100644 index 0000000..8560a12 --- /dev/null +++ b/yajl/yajl_lex.c @@ -0,0 +1,778 @@ +/* + * Copyright (c) 2007-2014, Lloyd Hilaiel <me@lloyd.io> + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include "yajl_lex.h" +#include "yajl_buf.h" + +#include <stdlib.h> +#include <stdio.h> +#include <assert.h> +#include <string.h> + +#ifdef YAJL_LEXER_DEBUG +static const char * +tokToStr(yajl_tok tok) +{ + switch (tok) { + case yajl_tok_bool: return "bool"; + case yajl_tok_colon: return "colon"; + case yajl_tok_comma: return "comma"; + case yajl_tok_eof: return "eof"; + case yajl_tok_error: return "error"; + case yajl_tok_left_brace: return "brace"; + case yajl_tok_left_bracket: return "bracket"; + case yajl_tok_null: return "null"; + case yajl_tok_integer: return "integer"; + case yajl_tok_double: return "double"; + case yajl_tok_right_brace: return "brace"; + case yajl_tok_right_bracket: return "bracket"; + case yajl_tok_string: return "string"; + case yajl_tok_string_with_escapes: return "string_with_escapes"; + case yajl_tok_c_comment: return "C comment"; + case yajl_tok_cpp_comment: return "C++ comment"; + } + return "unknown"; +} +#endif + +/* Impact of the stream parsing feature on the lexer: + * + * YAJL support stream parsing. That is, the ability to parse the first + * bits of a chunk of JSON before the last bits are available (still on + * the network or disk). This makes the lexer more complex. The + * responsibility of the lexer is to handle transparently the case where + * a chunk boundary falls in the middle of a token. This is + * accomplished is via a buffer and a character reading abstraction. + * + * Overview of implementation + * + * When we lex to end of input string before end of token is hit, we + * copy all of the input text composing the token into our lexBuf. + * + * Every time we read a character, we do so through the readChar function. + * readChar's responsibility is to handle pulling all chars from the buffer + * before pulling chars from input text + */ + +struct yajl_lexer_t { + /* the overal line and char offset into the data */ + size_t lineOff; + size_t charOff; + + /* error */ + yajl_lex_error error; + + /* a input buffer to handle the case where a token is spread over + * multiple chunks */ + yajl_buf buf; + + /* in the case where we have data in the lexBuf, bufOff holds + * the current offset into the lexBuf. */ + size_t bufOff; + + /* are we using the lex buf? */ + unsigned int bufInUse; + + /* shall we allow comments? */ + unsigned int allowComments; + + /* shall we validate utf8 inside strings? */ + unsigned int validateUTF8; + + yajl_alloc_funcs * alloc; +}; + +#define readChar(lxr, txt, off) \ + (((lxr)->bufInUse && yajl_buf_len((lxr)->buf) && lxr->bufOff < yajl_buf_len((lxr)->buf)) ? \ + (*((const unsigned char *) yajl_buf_data((lxr)->buf) + ((lxr)->bufOff)++)) : \ + ((txt)[(*(off))++])) + +#define unreadChar(lxr, off) ((*(off) > 0) ? (*(off))-- : ((lxr)->bufOff--)) + +yajl_lexer +yajl_lex_alloc(yajl_alloc_funcs * alloc, + unsigned int allowComments, unsigned int validateUTF8) +{ + yajl_lexer lxr = (yajl_lexer) YA_MALLOC(alloc, sizeof(struct yajl_lexer_t)); + memset((void *) lxr, 0, sizeof(struct yajl_lexer_t)); + lxr->buf = yajl_buf_alloc(alloc); + lxr->allowComments = allowComments; + lxr->validateUTF8 = validateUTF8; + lxr->alloc = alloc; + return lxr; +} + +void +yajl_lex_free(yajl_lexer lxr) +{ + yajl_buf_free(lxr->buf); + YA_FREE(lxr->alloc, lxr); + return; +} + +/* a lookup table which lets us quickly determine three things: + * VEC - valid escaped control char + * note. the solidus '/' may be escaped or not. + * IJC - invalid json char + * VHC - valid hex char + * NFP - needs further processing (from a string scanning perspective) + * NUC - needs utf8 checking when enabled (from a string scanning perspective) + */ +#define VEC 0x01 +#define IJC 0x02 +#define VHC 0x04 +#define NFP 0x08 +#define NUC 0x10 + +static const char charLookupTable[256] = +{ +/*00*/ IJC , IJC , IJC , IJC , IJC , IJC , IJC , IJC , +/*08*/ IJC , IJC , IJC , IJC , IJC , IJC , IJC , IJC , +/*10*/ IJC , IJC , IJC , IJC , IJC , IJC , IJC , IJC , +/*18*/ IJC , IJC , IJC , IJC , IJC , IJC , IJC , IJC , + +/*20*/ 0 , 0 , NFP|VEC|IJC, 0 , 0 , 0 , 0 , 0 , +/*28*/ 0 , 0 , 0 , 0 , 0 , 0 , 0 , VEC , +/*30*/ VHC , VHC , VHC , VHC , VHC , VHC , VHC , VHC , +/*38*/ VHC , VHC , 0 , 0 , 0 , 0 , 0 , 0 , + +/*40*/ 0 , VHC , VHC , VHC , VHC , VHC , VHC , 0 , +/*48*/ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , +/*50*/ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , +/*58*/ 0 , 0 , 0 , 0 , NFP|VEC|IJC, 0 , 0 , 0 , + +/*60*/ 0 , VHC , VEC|VHC, VHC , VHC , VHC , VEC|VHC, 0 , +/*68*/ 0 , 0 , 0 , 0 , 0 , 0 , VEC , 0 , +/*70*/ 0 , 0 , VEC , 0 , VEC , 0 , 0 , 0 , +/*78*/ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , + + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC , + NUC , NUC , NUC , NUC , NUC , NUC , NUC , NUC +}; + +/** process a variable length utf8 encoded codepoint. + * + * returns: + * yajl_tok_string - if valid utf8 char was parsed and offset was + * advanced + * yajl_tok_eof - if end of input was hit before validation could + * complete + * yajl_tok_error - if invalid utf8 was encountered + * + * NOTE: on error the offset will point to the first char of the + * invalid utf8 */ +#define UTF8_CHECK_EOF if (*offset >= jsonTextLen) { return yajl_tok_eof; } + +static yajl_tok +yajl_lex_utf8_char(yajl_lexer lexer, const unsigned char * jsonText, + size_t jsonTextLen, size_t * offset, + unsigned char curChar) +{ + if (curChar <= 0x7f) { + /* single byte */ + return yajl_tok_string; + } else if ((curChar >> 5) == 0x6) { + /* two byte */ + UTF8_CHECK_EOF; + curChar = readChar(lexer, jsonText, offset); + if ((curChar >> 6) == 0x2) return yajl_tok_string; + } else if ((curChar >> 4) == 0x0e) { + /* three byte */ + UTF8_CHECK_EOF; + curChar = readChar(lexer, jsonText, offset); + if ((curChar >> 6) == 0x2) { + UTF8_CHECK_EOF; + curChar = readChar(lexer, jsonText, offset); + if ((curChar >> 6) == 0x2) return yajl_tok_string; + } + } else if ((curChar >> 3) == 0x1e) { + /* four byte */ + UTF8_CHECK_EOF; + curChar = readChar(lexer, jsonText, offset); + if ((curChar >> 6) == 0x2) { + UTF8_CHECK_EOF; + curChar = readChar(lexer, jsonText, offset); + if ((curChar >> 6) == 0x2) { + UTF8_CHECK_EOF; + curChar = readChar(lexer, jsonText, offset); + if ((curChar >> 6) == 0x2) return yajl_tok_string; + } + } + } + + return yajl_tok_error; +} + +/* lex a string. input is the lexer, pointer to beginning of + * json text, and start of string (offset). + * a token is returned which has the following meanings: + * yajl_tok_string: lex of string was successful. offset points to + * terminating '"'. + * yajl_tok_eof: end of text was encountered before we could complete + * the lex. + * yajl_tok_error: embedded in the string were unallowable chars. offset + * points to the offending char + */ +#define STR_CHECK_EOF \ +if (*offset >= jsonTextLen) { \ + tok = yajl_tok_eof; \ + goto finish_string_lex; \ +} + +/** scan a string for interesting characters that might need further + * review. return the number of chars that are uninteresting and can + * be skipped. + * (lth) hi world, any thoughts on how to make this routine faster? */ +static size_t +yajl_string_scan(const unsigned char * buf, size_t len, int utf8check) +{ + unsigned char mask = IJC|NFP|(utf8check ? NUC : 0); + size_t skip = 0; + while (skip < len && !(charLookupTable[*buf] & mask)) + { + skip++; + buf++; + } + return skip; +} + +static yajl_tok +yajl_lex_string(yajl_lexer lexer, const unsigned char * jsonText, + size_t jsonTextLen, size_t * offset) +{ + yajl_tok tok = yajl_tok_error; + int hasEscapes = 0; + + for (;;) { + unsigned char curChar; + + /* now jump into a faster scanning routine to skip as much + * of the buffers as possible */ + { + const unsigned char * p; + size_t len; + + if ((lexer->bufInUse && yajl_buf_len(lexer->buf) && + lexer->bufOff < yajl_buf_len(lexer->buf))) + { + p = ((const unsigned char *) yajl_buf_data(lexer->buf) + + (lexer->bufOff)); + len = yajl_buf_len(lexer->buf) - lexer->bufOff; + lexer->bufOff += yajl_string_scan(p, len, lexer->validateUTF8); + } + else if (*offset < jsonTextLen) + { + p = jsonText + *offset; + len = jsonTextLen - *offset; + *offset += yajl_string_scan(p, len, lexer->validateUTF8); + } + } + + STR_CHECK_EOF; + + curChar = readChar(lexer, jsonText, offset); + + /* quote terminates */ + if (curChar == '"') { + tok = yajl_tok_string; + break; + } + /* backslash escapes a set of control chars, */ + else if (curChar == '\\') { + hasEscapes = 1; + STR_CHECK_EOF; + + /* special case \u */ + curChar = readChar(lexer, jsonText, offset); + if (curChar == 'u') { + unsigned int i = 0; + + for (i=0;i<4;i++) { + STR_CHECK_EOF; + curChar = readChar(lexer, jsonText, offset); + if (!(charLookupTable[curChar] & VHC)) { + /* back up to offending char */ + unreadChar(lexer, offset); + lexer->error = yajl_lex_string_invalid_hex_char; + goto finish_string_lex; + } + } + } else if (!(charLookupTable[curChar] & VEC)) { + /* back up to offending char */ + unreadChar(lexer, offset); + lexer->error = yajl_lex_string_invalid_escaped_char; + goto finish_string_lex; + } + } + /* when not validating UTF8 it's a simple table lookup to determine + * if the present character is invalid */ + else if(charLookupTable[curChar] & IJC) { + /* back up to offending char */ + unreadChar(lexer, offset); + lexer->error = yajl_lex_string_invalid_json_char; + goto finish_string_lex; + } + /* when in validate UTF8 mode we need to do some extra work */ + else if (lexer->validateUTF8) { + yajl_tok t = yajl_lex_utf8_char(lexer, jsonText, jsonTextLen, + offset, curChar); + + if (t == yajl_tok_eof) { + tok = yajl_tok_eof; + goto finish_string_lex; + } else if (t == yajl_tok_error) { + lexer->error = yajl_lex_string_invalid_utf8; + goto finish_string_lex; + } + } + /* accept it, and move on */ + } + finish_string_lex: + /* tell our buddy, the parser, wether he needs to process this string + * again */ + if (hasEscapes && tok == yajl_tok_string) { + tok = yajl_tok_string_with_escapes; + } + + return tok; +} + +#define RETURN_IF_EOF if (*offset >= jsonTextLen) return yajl_tok_eof; + +static yajl_tok +yajl_lex_number(yajl_lexer lexer, const unsigned char * jsonText, + size_t jsonTextLen, size_t * offset) +{ + /** XXX: numbers are the only entities in json that we must lex + * _beyond_ in order to know that they are complete. There + * is an ambiguous case for integers at EOF. */ + + unsigned char c; + + yajl_tok tok = yajl_tok_integer; + + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + + /* optional leading minus */ + if (c == '-') { + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + } + + /* a single zero, or a series of integers */ + if (c == '0') { + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + } else if (c >= '1' && c <= '9') { + do { + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + } while (c >= '0' && c <= '9'); + } else { + unreadChar(lexer, offset); + lexer->error = yajl_lex_missing_integer_after_minus; + return yajl_tok_error; + } + + /* optional fraction (indicates this is floating point) */ + if (c == '.') { + int numRd = 0; + + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + + while (c >= '0' && c <= '9') { + numRd++; + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + } + + if (!numRd) { + unreadChar(lexer, offset); + lexer->error = yajl_lex_missing_integer_after_decimal; + return yajl_tok_error; + } + tok = yajl_tok_double; + } + + /* optional exponent (indicates this is floating point) */ + if (c == 'e' || c == 'E') { + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + + /* optional sign */ + if (c == '+' || c == '-') { + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + } + + if (c >= '0' && c <= '9') { + do { + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + } while (c >= '0' && c <= '9'); + } else { + unreadChar(lexer, offset); + lexer->error = yajl_lex_missing_integer_after_exponent; + return yajl_tok_error; + } + tok = yajl_tok_double; + } + + /* we always go "one too far" */ + unreadChar(lexer, offset); + + return tok; +} + +static yajl_tok +yajl_lex_comment(yajl_lexer lexer, const unsigned char * jsonText, + size_t jsonTextLen, size_t * offset) +{ + unsigned char c; + + yajl_tok tok; + + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + + /* either slash or star expected */ + if (c == '/') { + tok = yajl_tok_cpp_comment; + /* now we throw away until end of line */ + do { + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + } while (c != '\n'); + } else if (c == '*') { + tok = yajl_tok_c_comment; + /* now we throw away until end of comment */ + for (;;) { + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + if (c == '*') { + RETURN_IF_EOF; + c = readChar(lexer, jsonText, offset); + if (c == '/') { + break; + } else { + unreadChar(lexer, offset); + } + } + } + } else { + lexer->error = yajl_lex_invalid_char; + tok = yajl_tok_error; + } + + return tok; +} + +yajl_tok +yajl_lex_lex(yajl_lexer lexer, const unsigned char * jsonText, + size_t jsonTextLen, size_t * offset, + const unsigned char ** outBuf, size_t * outLen) +{ + yajl_tok tok = yajl_tok_error; + unsigned char c; + size_t startOffset = *offset; + + *outBuf = NULL; + *outLen = 0; + + for (;;) { + assert(*offset <= jsonTextLen); + + if (*offset >= jsonTextLen) { + tok = yajl_tok_eof; + goto lexed; + } + + c = readChar(lexer, jsonText, offset); + + switch (c) { + case '{': + tok = yajl_tok_left_bracket; + goto lexed; + case '}': + tok = yajl_tok_right_bracket; + goto lexed; + case '[': + tok = yajl_tok_left_brace; + goto lexed; + case ']': + tok = yajl_tok_right_brace; + goto lexed; + case ',': + tok = yajl_tok_comma; + goto lexed; + case ':': + tok = yajl_tok_colon; + goto lexed; + case '\t': case '\n': case '\v': case '\f': case '\r': case ' ': + startOffset++; + break; + case 't': { + const char * want = "rue"; + do { + if (*offset >= jsonTextLen) { + tok = yajl_tok_eof; + goto lexed; + } + c = readChar(lexer, jsonText, offset); + if (c != *want) { + unreadChar(lexer, offset); + lexer->error = yajl_lex_invalid_string; + tok = yajl_tok_error; + goto lexed; + } + } while (*(++want)); + tok = yajl_tok_bool; + goto lexed; + } + case 'f': { + const char * want = "alse"; + do { + if (*offset >= jsonTextLen) { + tok = yajl_tok_eof; + goto lexed; + } + c = readChar(lexer, jsonText, offset); + if (c != *want) { + unreadChar(lexer, offset); + lexer->error = yajl_lex_invalid_string; + tok = yajl_tok_error; + goto lexed; + } + } while (*(++want)); + tok = yajl_tok_bool; + goto lexed; + } + case 'n': { + const char * want = "ull"; + do { + if (*offset >= jsonTextLen) { + tok = yajl_tok_eof; + goto lexed; + } + c = readChar(lexer, jsonText, offset); + if (c != *want) { + unreadChar(lexer, offset); + lexer->error = yajl_lex_invalid_string; + tok = yajl_tok_error; + goto lexed; + } + } while (*(++want)); + tok = yajl_tok_null; + goto lexed; + } + case '"': { + tok = yajl_lex_string(lexer, (const unsigned char *) jsonText, + jsonTextLen, offset); + goto lexed; + } + case '-': + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': { + /* integer parsing wants to start from the beginning */ + unreadChar(lexer, offset); + tok = yajl_lex_number(lexer, (const unsigned char *) jsonText, + jsonTextLen, offset); + goto lexed; + } + case '/': + /* hey, look, a probable comment! If comments are disabled + * it's an error. */ + if (!lexer->allowComments) { + unreadChar(lexer, offset); + lexer->error = yajl_lex_unallowed_comment; + tok = yajl_tok_error; + goto lexed; + } + /* if comments are enabled, then we should try to lex + * the thing. possible outcomes are + * - successful lex (tok_comment, which means continue), + * - malformed comment opening (slash not followed by + * '*' or '/') (tok_error) + * - eof hit. (tok_eof) */ + tok = yajl_lex_comment(lexer, (const unsigned char *) jsonText, + jsonTextLen, offset); + if (tok == yajl_tok_c_comment + || tok == yajl_tok_cpp_comment) { + goto lexed; + } + /* hit error or eof, bail */ + goto lexed; + default: + lexer->error = yajl_lex_invalid_char; + tok = yajl_tok_error; + goto lexed; + } + } + + + lexed: + /* need to append to buffer if the buffer is in use or + * if it's an EOF token */ + if (tok == yajl_tok_eof || lexer->bufInUse) { + if (!lexer->bufInUse) yajl_buf_clear(lexer->buf); + lexer->bufInUse = 1; + yajl_buf_append(lexer->buf, jsonText + startOffset, *offset - startOffset); + lexer->bufOff = 0; + + if (tok != yajl_tok_eof) { + *outBuf = yajl_buf_data(lexer->buf); + *outLen = yajl_buf_len(lexer->buf); + lexer->bufInUse = 0; + } + } else if (tok != yajl_tok_error) { + *outBuf = jsonText + startOffset; + *outLen = *offset - startOffset; + } + + /* special case for strings. skip the quotes. */ + if (tok == yajl_tok_string || tok == yajl_tok_string_with_escapes) + { + assert(*outLen >= 2); + (*outBuf)++; + *outLen -= 2; + } + + /* remove comment delimeters */ + if (tok == yajl_tok_c_comment) + { + assert(*outLen >= 4); + (*outBuf)+= 2; + *outLen -= 4; + } + if (tok == yajl_tok_cpp_comment) + { + assert(*outLen >= 2); + (*outBuf)+= 2; + *outLen -= 2; + + if (*outLen >= 1 && (*outBuf)[(*outLen)-1] == 0x0a) + *outLen -= 1; + } + +#ifdef YAJL_LEXER_DEBUG + if (tok == yajl_tok_error) { + printf("lexical error: %s\n", + yajl_lex_error_to_string(yajl_lex_get_error(lexer))); + } else if (tok == yajl_tok_eof) { + printf("EOF hit\n"); + } else { + printf("lexed %s: '", tokToStr(tok)); + fwrite(*outBuf, 1, *outLen, stdout); + printf("'\n"); + } +#endif + + return tok; +} + +const char * +yajl_lex_error_to_string(yajl_lex_error error) +{ + switch (error) { + case yajl_lex_e_ok: + return "ok, no error"; + case yajl_lex_string_invalid_utf8: + return "invalid bytes in UTF8 string."; + case yajl_lex_string_invalid_escaped_char: + return "inside a string, '\\' occurs before a character " + "which it may not."; + case yajl_lex_string_invalid_json_char: + return "invalid character inside string."; + case yajl_lex_string_invalid_hex_char: + return "invalid (non-hex) character occurs after '\\u' inside " + "string."; + case yajl_lex_invalid_char: + return "invalid char in json text."; + case yajl_lex_invalid_string: + return "invalid string in json text."; + case yajl_lex_missing_integer_after_exponent: + return "malformed number, a digit is required after the exponent."; + case yajl_lex_missing_integer_after_decimal: + return "malformed number, a digit is required after the " + "decimal point."; + case yajl_lex_missing_integer_after_minus: + return "malformed number, a digit is required after the " + "minus sign."; + case yajl_lex_unallowed_comment: + return "probable comment found in input text, comments are " + "not enabled."; + } + return "unknown error code"; +} + + +/** allows access to more specific information about the lexical + * error when yajl_lex_lex returns yajl_tok_error. */ +yajl_lex_error +yajl_lex_get_error(yajl_lexer lexer) +{ + if (lexer == NULL) return (yajl_lex_error) -1; + return lexer->error; +} + +size_t yajl_lex_current_line(yajl_lexer lexer) +{ + return lexer->lineOff; +} + +size_t yajl_lex_current_char(yajl_lexer lexer) +{ + return lexer->charOff; +} + +yajl_tok yajl_lex_peek(yajl_lexer lexer, const unsigned char * jsonText, + size_t jsonTextLen, size_t offset) +{ + const unsigned char * outBuf; + size_t outLen; + size_t bufLen = yajl_buf_len(lexer->buf); + size_t bufOff = lexer->bufOff; + unsigned int bufInUse = lexer->bufInUse; + yajl_tok tok; + + tok = yajl_lex_lex(lexer, jsonText, jsonTextLen, &offset, + &outBuf, &outLen); + + lexer->bufOff = bufOff; + lexer->bufInUse = bufInUse; + yajl_buf_truncate(lexer->buf, bufLen); + + return tok; +} |