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Gene Selkov's SEG datatype (GiST example code)

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Tom Lane
2000-12-11 20:40:33 +00:00
parent 9892ddf5ee
commit a3694b420f
14 changed files with 6076 additions and 0 deletions
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contrib/seg/segparse.y Normal file
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%{
#define YYERROR_VERBOSE
#define YYPARSE_PARAM result /* need this to pass a pointer (void *) to yyparse */
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include "segdata.h"
#include "buffer.h"
#include "postgres.h"
#include "utils/elog.h"
#undef yylex /* falure to redefine yylex will result in calling the */
#define yylex seg_yylex /* wrong scanner when running inside postgres backend */
extern int errno;
extern int yylex(); /* defined as seg_yylex in segscan.c */
extern int significant_digits( char *str ); /* defined in seg.c */
int seg_yyerror( char *msg );
int seg_yyparse( void *result );
float seg_atof( char *value );
#define MAX(X,Y) ((X) > (Y) ? (X) : (Y))
#define MIN(X,Y) ((X) < (Y) ? (X) : (Y))
#define ABS(X) ((X) < 0 ? (-X) : (X))
long threshold;
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 */
%union {
struct BND {
float val;
char ext;
char sigd;
} bnd;
char * text;
}
%token <text> FLOAT
%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 ) {
reset_parse_buffer();
elog(ERROR, "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;
((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;
((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:
FLOAT {
$$.ext = '\0';
$$.sigd = significant_digits($1);
$$.val = seg_atof($1);
}
|
EXTENSION FLOAT {
$$.ext = $1[0];
$$.sigd = significant_digits($2);
$$.val = seg_atof($2);
}
;
deviation:
FLOAT {
$$.ext = '\0';
$$.sigd = significant_digits($1);
$$.val = seg_atof($1);
}
;
%%
float seg_atof ( char *value ) {
float result;
char *buf = (char *) palloc(256);
errno = 0;
sscanf(value, "%f", &result);
if ( errno ) {
sprintf(buf, "numeric value %s unrepresentable", value);
reset_parse_buffer();
elog(ERROR, buf);
}
return result;
}
int seg_yyerror ( char *msg ) {
char *buf = (char *) palloc(256);
int position;
yyclearin;
if ( !strcmp(msg, "parse error, expecting `$'") ) {
msg = "expecting end of input";
}
position = parse_buffer_pos() > parse_buffer_size() ? parse_buffer_pos() - 1 : parse_buffer_pos();
sprintf(
buf,
"%s at or near position %d, character ('%c', \\%03o), input: '%s'\n",
msg,
position,
parse_buffer()[position - 1],
parse_buffer()[position - 1],
parse_buffer()
);
reset_parse_buffer();
elog(ERROR, buf);
return 0;
}