Support Infinity and NaN.

Author: df7cb

NEWS.md

@@ -7,6 +7,7 @@
 * Remove bison 2 compat mode, but keep pregenerated files for jessie and
   trusty.
 * Support send/receive via the binary protocol.
+* Support Infinity and NaN.
 
 6.0: Mar 7, 2018
 ----------------

debian/changelog

@@ -7,6 +7,7 @@ postgresql-unit (7.0-1) UNRELEASED; urgency=medium
   * Remove bison 2 compat mode, but keep pregenerated files for jessie and
     trusty.
   * Support send/receive via the binary protocol.
+  * Support Infinity and NaN.
 
  -- Christoph Berg <[email protected]>  Sun, 08 Jul 2018 21:46:17 +0200
 

expected/unit.out

@@ -178,6 +178,31 @@ SELECT '1 foobar'::unit AS error;
 ERROR:  unit "foobar" is not known
 LINE 1: SELECT '1 foobar'::unit AS error;
                ^
+-- special values
+SELECT '-0'::unit, -'0'::unit, '-0 m'::unit, -'0 m'::unit;
+ unit | ?column? | unit | ?column? 
+------+----------+------+----------
+ -0   | -0       | -0 m | -0 m
+(1 row)
+
+SELECT 'infinity'::unit, 'Infinity m'::unit, 'inf A'::unit;
+   unit   |    unit    |    unit    
+----------+------------+------------
+ Infinity | Infinity m | Infinity A
+(1 row)
+
+SELECT '-infinity'::unit, '-Infinity m'::unit, 'Inf A'::unit;
+   unit    |    unit     |    unit    
+-----------+-------------+------------
+ -Infinity | -Infinity m | Infinity A
+(1 row)
+
+SELECT 'nan'::unit, 'NaN'::unit;
+ unit | unit 
+------+------
+ NaN  | NaN
+(1 row)
+
 -- test parser arithmetic
 SELECT '1|10'::unit, '1|10 m'::unit;
  unit |  unit  

float8out_internal.h

@@ -11,6 +11,12 @@ float8out_internal(double num)
 
 	if (isnan(num))
 		return strcpy(ascii, "NaN");
+	if (!isfinite(num)) {
+		if (num > 0)
+			return strcpy(ascii, "Infinity");
+		else
+			return strcpy(ascii, "-Infinity");
+	}
 
 	if (ndig < 1)
 		ndig = 1;

sql/unit.sql

@@ -39,6 +39,12 @@ SELECT '10 dm^3'::unit, '10l'::unit;
 SELECT '9.81 kg*m/s^2'::unit, '9.81 kg*m/s*s'::unit, '9.81 kg*m/s/s'::unit;
 SELECT '1 foobar'::unit AS error;
 
+-- special values
+SELECT '-0'::unit, -'0'::unit, '-0 m'::unit, -'0 m'::unit;
+SELECT 'infinity'::unit, 'Infinity m'::unit, 'inf A'::unit;
+SELECT '-infinity'::unit, '-Infinity m'::unit, 'Inf A'::unit;
+SELECT 'nan'::unit, 'NaN'::unit;
+
 -- test parser arithmetic
 SELECT '1|10'::unit, '1|10 m'::unit;
 SELECT '2 m + 3 m - 4 m'::unit, '6 m - 3 m - 2 m'::unit, '6 m - 3 m + 1 m'::unit;

unitparse.l

@@ -18,6 +18,7 @@ GNU General Public License for more details.
 #include <executor/spi.h>
 #include <utils/builtins.h> /* CStringGetTextDatum */
 #include <catalog/pg_type.h> /* TEXTOID */
+#include <math.h> /* INFINITY, NAN */
 
 #define when(x) if (!strcmp(yytext, x))
 %}
@@ -73,6 +74,16 @@ SUPER_9     \xe2\x81\xb9
 	return DOUBLE;
 }
 
+[Ii][Nn][Ff]([Ii][Nn][Ii][Tt][Yy])? {
+	yyunitlval.DOUBLE = INFINITY;
+	return DOUBLE;
+}
+
+[Nn][Aa][Nn] {
+	yyunitlval.DOUBLE = NAN;
+	return DOUBLE;
+}
+
 {TIME_R} { /* hh:mm:ss[.sss] */
 	char *colon;
 	yyunitlval.DOUBLE = TIME_HOUR * atoi(yytext); /* hh */