postgresql/contrib/seg/segparse.y

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%{
#define YYPARSE_PARAM result /* need this to pass a pointer (void *) to yyparse */
#include "postgres.h"
#include <math.h>
#include "fmgr.h"
#include "utils/builtins.h"
#include "segdata.h"
/*
* Bison doesn't allocate anything that needs to live across parser calls,
* so we can easily have it use palloc instead of malloc. This prevents
* memory leaks if we error out during parsing. Note this only works with
* bison >= 2.0. However, in bison 1.875 the default is to use alloca()
* if possible, so there's not really much problem anyhow, at least if
* you're building with gcc.
*/
#define YYMALLOC palloc
#define YYFREE pfree
extern int seg_yylex(void);
extern int significant_digits(char *str); /* defined in seg.c */
void seg_yyerror(const char *message);
int seg_yyparse(void *result);
static float seg_atof(char *value);
static char strbuf[25] = {
'0', '0', '0', '0', '0',
'0', '0', '0', '0', '0',
'0', '0', '0', '0', '0',
'0', '0', '0', '0', '0',
'0', '0', '0', '0', '\0'
};
%}
/* BISON Declarations */
%expect 0
%name-prefix="seg_yy"
%union {
struct BND {
float val;
char ext;
char sigd;
} bnd;
char * text;
}
%token <text> SEGFLOAT
%token <text> RANGE
%token <text> PLUMIN
%token <text> EXTENSION
%type <bnd> boundary
%type <bnd> deviation
%start range
/* Grammar follows */
%%
range:
boundary PLUMIN deviation {
((SEG *)result)->lower = $1.val - $3.val;
((SEG *)result)->upper = $1.val + $3.val;
sprintf(strbuf, "%g", ((SEG *)result)->lower);
((SEG *)result)->l_sigd = Max(Min(6, significant_digits(strbuf)), Max($1.sigd, $3.sigd));
sprintf(strbuf, "%g", ((SEG *)result)->upper);
((SEG *)result)->u_sigd = Max(Min(6, significant_digits(strbuf)), Max($1.sigd, $3.sigd));
((SEG *)result)->l_ext = '\0';
((SEG *)result)->u_ext = '\0';
}
|
boundary RANGE boundary {
((SEG *)result)->lower = $1.val;
((SEG *)result)->upper = $3.val;
if ( ((SEG *)result)->lower > ((SEG *)result)->upper ) {
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("swapped boundaries: %g is greater than %g",
((SEG *)result)->lower, ((SEG *)result)->upper)));
YYERROR;
}
((SEG *)result)->l_sigd = $1.sigd;
((SEG *)result)->u_sigd = $3.sigd;
((SEG *)result)->l_ext = ( $1.ext ? $1.ext : '\0' );
((SEG *)result)->u_ext = ( $3.ext ? $3.ext : '\0' );
}
|
boundary RANGE {
((SEG *)result)->lower = $1.val;
((SEG *)result)->upper = HUGE_VAL;
((SEG *)result)->l_sigd = $1.sigd;
((SEG *)result)->u_sigd = 0;
((SEG *)result)->l_ext = ( $1.ext ? $1.ext : '\0' );
((SEG *)result)->u_ext = '-';
}
|
RANGE boundary {
((SEG *)result)->lower = -HUGE_VAL;
((SEG *)result)->upper = $2.val;
((SEG *)result)->l_sigd = 0;
((SEG *)result)->u_sigd = $2.sigd;
((SEG *)result)->l_ext = '-';
((SEG *)result)->u_ext = ( $2.ext ? $2.ext : '\0' );
}
|
boundary {
((SEG *)result)->lower = ((SEG *)result)->upper = $1.val;
((SEG *)result)->l_sigd = ((SEG *)result)->u_sigd = $1.sigd;
((SEG *)result)->l_ext = ((SEG *)result)->u_ext = ( $1.ext ? $1.ext : '\0' );
}
;
boundary:
SEGFLOAT {
/* temp variable avoids a gcc 3.3.x bug on Sparc64 */
float val = seg_atof($1);
$$.ext = '\0';
$$.sigd = significant_digits($1);
$$.val = val;
}
|
EXTENSION SEGFLOAT {
/* temp variable avoids a gcc 3.3.x bug on Sparc64 */
float val = seg_atof($2);
$$.ext = $1[0];
$$.sigd = significant_digits($2);
$$.val = val;
}
;
deviation:
SEGFLOAT {
/* temp variable avoids a gcc 3.3.x bug on Sparc64 */
float val = seg_atof($1);
$$.ext = '\0';
$$.sigd = significant_digits($1);
$$.val = val;
}
;
%%
static float
seg_atof(char *value)
{
Datum datum;
datum = DirectFunctionCall1(float4in, CStringGetDatum(value));
return DatumGetFloat4(datum);
}
#include "segscan.c"