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

   1 %{
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include "csv.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) {
  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) {
  24         field_buffer[field_pos++] = *s++;
  25     }
  26     field_buffer[field_pos] = '\0';
  27 }
  28
  29 char* get_field_content() {
  30     return strdup(field_buffer);
  31 }
  32 %}
  33
  34 %option noyywrap
  35 %option yylineno
  36
  37 %x ESCAPED_FIELD
  38
  39 TEXTDATA    [\x20-\x21\x23-\x2B\x2D-\x7E]
  40 COMMA       \x2C
  41 CR          \x0D
  42 LF          \x0A
  43 DQUOTE      \x22
  44 CRLF        {CR}{LF}
  45
  46 %%
  47
  48 {COMMA}                 { return COMMA_TOK; }
  49
  50 {CRLF}                  { return CRLF_TOK; }
  51
  52 {LF}                    { return CRLF_TOK; }
  53
  54 {DQUOTE}                {
  55                           reset_field_buffer();
  56                           BEGIN(ESCAPED_FIELD);
  57                         }
  58
  59 <ESCAPED_FIELD>{DQUOTE}{DQUOTE}  { append_to_field('"'); }
  60
  61 <ESCAPED_FIELD>{DQUOTE}          {
  62                                    yylval.str = get_field_content();
  63                                    BEGIN(INITIAL);
  64                                    return FIELD_TOK;
  65                                  }
  66
  67 <ESCAPED_FIELD>{TEXTDATA}        { append_to_field(yytext[0]); }
  68
  69 <ESCAPED_FIELD>{COMMA}           { append_to_field(','); }
  70
  71 <ESCAPED_FIELD>{CR}              { append_to_field('\r'); }
  72
  73 <ESCAPED_FIELD>{LF}              { append_to_field('\n'); }
  74
  75 <ESCAPED_FIELD>.                 { append_to_field(yytext[0]); }
  76
  77 {TEXTDATA}+             {
  78                           yylval.str = strdup(yytext);
  79                           return FIELD_TOK;
  80                         }
  81
  82 [ \t]                   { /* ignore whitespace outside of fields */ }
  83
  84 .                       { return yytext[0]; }
  85
  86 %%