begriffs open source - sa-parse/blob - src/csv.l

   1 %{
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include "y.tab.h"
   5
   6 /* Buffer for building field content */
   7 static char field_buffer[8192];
   8 static int field_pos = 0;
   9
  10 void reset_field_buffer() {
  11     field_pos = 0;
  12     field_buffer[0] = '\0';
  13 }
  14
  15 void append_to_field(char c) {
  16     if (field_pos < sizeof(field_buffer) - 1) {  /* Reserve space for null terminator */
  17         field_buffer[field_pos++] = c;
  18         field_buffer[field_pos] = '\0';
  19     }
  20 }
  21
  22 void append_string_to_field(const char* s) {
  23     while (*s && field_pos < sizeof(field_buffer) - 1) {  /* Reserve space for null terminator */
  24         field_buffer[field_pos++] = *s++;
  25     }
  26     field_buffer[field_pos] = '\0';
  27 }
  28
  29 char* get_field_content() {
  30     char* result = strdup(field_buffer);  /* NOTE: Caller must free() this memory */
  31     if (!result) {
  32         fprintf(stderr, "Memory allocation failed in get_field_content()\n");
  33         exit(1);  /* Conservative approach: exit on memory failure */
  34     }
  35     return result;
  36 }
  37 %}
  38
  39 %option noyywrap
  40 %option yylineno
  41
  42 %x ESCAPED_FIELD
  43
  44 TEXTDATA    [\x20-\x21\x23-\x2B\x2D-\x7E]
  45 COMMA       \x2C
  46 CR          \x0D
  47 LF          \x0A
  48 DQUOTE      \x22
  49 CRLF        {CR}{LF}
  50
  51 %%
  52
  53 {COMMA}                 { return COMMA_TOK; }
  54
  55 {CRLF}                  { return CRLF_TOK; }
  56
  57 {LF}                    { return CRLF_TOK; }
  58
  59 {DQUOTE}                {
  60                           reset_field_buffer();
  61                           BEGIN(ESCAPED_FIELD);
  62                         }
  63
  64 <ESCAPED_FIELD>{DQUOTE}{DQUOTE}  { append_to_field('"'); }
  65
  66 <ESCAPED_FIELD>{DQUOTE}          {
  67                                    yylval.str = get_field_content();
  68                                    BEGIN(INITIAL);
  69                                    return FIELD_TOK;
  70                                  }
  71
  72 <ESCAPED_FIELD>{TEXTDATA}        { append_to_field(yytext[0]); }
  73
  74 <ESCAPED_FIELD>{COMMA}           { append_to_field(','); }
  75
  76 <ESCAPED_FIELD>{CR}              { append_to_field('\r'); }
  77
  78 <ESCAPED_FIELD>{LF}              { append_to_field('\n'); }
  79
  80 <ESCAPED_FIELD>.                 { append_to_field(yytext[0]); }
  81
  82 <ESCAPED_FIELD><<EOF>>           {
  83                                    /* Handle unterminated quoted field */
  84                                    yylval.str = get_field_content();
  85                                    BEGIN(INITIAL);
  86                                    return FIELD_TOK;
  87                                  }
  88
  89 {TEXTDATA}+             {
  90                           yylval.str = strdup(yytext);  /* NOTE: Caller must free() this memory */
  91                           if (!yylval.str) {
  92                               fprintf(stderr, "Memory allocation failed in TEXTDATA rule\n");
  93                               exit(1);  /* Conservative approach: exit on memory failure */
  94                           }
  95                           return FIELD_TOK;
  96                         }
  97
  98 [ \t]                   { /* ignore whitespace outside of fields */ }
  99
 100 .                       { return yytext[0]; }
 101
 102 %%