segscan.l

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%top{
/*
 * A scanner for EMP-style numeric ranges
 */
#include "postgres.h"
 
#include "nodes/miscnodes.h"
 
#include "segdata.h"
#include "segparse.h"   /* must be after segdata.h for SEG */
}
 
%{
/* LCOV_EXCL_START */
 
/* No reason to constrain amount of data slurped */
#define YY_READ_BUF_SIZE 16777216
 
/* Avoid exit() on fatal scanner errors (a bit ugly -- see yy_fatal_error) */
#undef fprintf
#define fprintf(file, fmt, msg)  fprintf_to_ereport(fmt, msg)
 
static void
fprintf_to_ereport(const char *fmt, const char *msg)
{
    ereport(ERROR, (errmsg_internal("%s", msg)));
}
%}
 
%option reentrant
%option bison-bridge
%option 8bit
%option never-interactive
%option nodefault
%option noinput
%option nounput
%option noyywrap
%option noyyalloc
%option noyyrealloc
%option noyyfree
%option warn
%option prefix="seg_yy"
 
 
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 SEGFLOAT;
<           yylval->text = "<"; return EXTENSION;
>           yylval->text = ">"; return EXTENSION;
\~           yylval->text = "~"; return EXTENSION;
[ \t\n\r\f\v]+ /* discard spaces */
.            return yytext[0]; /* alert parser of the garbage */
 
%%
 
/* LCOV_EXCL_STOP */
 
void
seg_yyerror(SEG *result, struct Node *escontext, yyscan_t yyscanner, const char *message)
{
    struct yyguts_t *yyg = (struct yyguts_t *) yyscanner;   /* needed for yytext
                                                             * macro */
 
    /* if we already reported an error, don't overwrite it */
    if (SOFT_ERROR_OCCURRED(escontext))
        return;
 
    if (*yytext == YY_END_OF_BUFFER_CHAR)
    {
        errsave(escontext,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("bad seg representation"),
        /* translator: %s is typically "syntax error" */
                 errdetail("%s at end of input", message)));
    }
    else
    {
        errsave(escontext,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("bad seg representation"),
        /* translator: first %s is typically "syntax error" */
                 errdetail("%s at or near \"%s\"", message, yytext)));
    }
}
 
 
/*
 * Called before any actual parsing is done
 */
void
seg_scanner_init(const char *str, yyscan_t *yyscannerp)
{
    yyscan_t    yyscanner;
 
    if (yylex_init(yyscannerp) != 0)
        elog(ERROR, "yylex_init() failed: %m");
 
    yyscanner = *yyscannerp;
 
    yy_scan_string(str, yyscanner);
}
 
 
/*
 * Called after parsing is done to clean up after seg_scanner_init()
 */
void
seg_scanner_finish(yyscan_t yyscanner)
{
    yylex_destroy(yyscanner);
}
 
/*
 * Interface functions to make flex use palloc() instead of malloc().
 * It'd be better to make these static, but flex insists otherwise.
 */
 
void *
yyalloc(yy_size_t size, yyscan_t yyscanner)
{
    return palloc(size);
}
 
void *
yyrealloc(void *ptr, yy_size_t size, yyscan_t yyscanner)
{
    if (ptr)
        return repalloc(ptr, size);
    else
        return palloc(size);
}
 
void
yyfree(void *ptr, yyscan_t yyscanner)
{
    if (ptr)
        pfree(ptr);
}