postgresql/contrib/seg/segscan.l

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%{
/*
** A scanner for EMP-style numeric ranges
*/
#include "postgres.h"
#include "buffer.h"
/* Avoid exit() on fatal scanner errors (a bit ugly -- see yy_fatal_error) */
#define fprintf(file, fmt, msg) ereport(ERROR, (errmsg_internal("%s", msg)))
/* flex screws a couple symbols when used with the -P option; fix those */
#define YY_DECL int seg_yylex YY_PROTO(( void )); \
int seg_yylex YY_PROTO(( void ))
#define yylval seg_yylval
/* redefined YY_INPUT reads byte-wise from the memory area defined in buffer.c */
#undef YY_INPUT
#define YY_INPUT(buf,result,max_size) \
{ \
int c = read_parse_buffer(); \
result = (c == '\0') ? YY_NULL : (buf[0] = c, 1); \
}
void seg_flush_scanner_buffer(void);
%}
%option 8bit
%option never-interactive
%option nounput
%option noyywrap
range (\.\.)(\.)?
plumin (\'\+\-\')|(\(\+\-)\)
integer [+-]?[0-9]+
real [+-]?[0-9]+\.[0-9]+
float ({integer}|{real})([eE]{integer})?
%%
{range} yylval.text = yytext; return RANGE;
{plumin} yylval.text = yytext; return PLUMIN;
{float} yylval.text = yytext; return FLOAT;
\< yylval.text = "<"; return EXTENSION;
\> yylval.text = ">"; return EXTENSION;
\~ yylval.text = "~"; return EXTENSION;
[ ]+ /* discard spaces */
. return yytext[0]; /* alert parser of the garbage */
%%
int seg_yylex();
void seg_flush_scanner_buffer(void) {
YY_FLUSH_BUFFER;
}