math.constants: add single float epsilon value

diff --git a/basis/math/constants/constants-docs.factor b/basis/math/constants/constants-docs.factor
index 4fdd9752026a28c102b15537a1107e11fac8fa2d..117cd70c67647a8a6f751503d368fda84c0f1683 100644 (file)
--- a/basis/math/constants/constants-docs.factor
+++ b/basis/math/constants/constants-docs.factor
@@ -7,7 +7,8 @@ ARTICLE: "math-constants" "Constants"
 { $subsection euler }
 { $subsection phi }
 { $subsection pi }
-{ $subsection epsilon } ;
+{ $subsection epsilon }
+{ $subsection single-epsilon } ;
 
 ABOUT: "math-constants"
 
@@ -25,4 +26,7 @@ HELP: pi
 { $values { "pi" "circumference of circle with diameter 1" } } ;
 
 HELP: epsilon
-{ $values { "epsilon" "smallest floating point value you can add to 1 without underflow" } } ;
+{ $values { "epsilon" "smallest double-precision floating point value you can add to 1 without underflow" } } ;
+
+HELP: single-epsilon
+{ $values { "epsilon" "smallest single-precision floating point value you can add to 1 without underflow" } } ;

diff --git a/basis/math/constants/constants.factor b/basis/math/constants/constants.factor
index a2d3213e78ce64f63597f74612e87a3f444e68a3..cb81ded8ea6728099a31fa7b997ddfe595344f63 100644 (file)
--- a/basis/math/constants/constants.factor
+++ b/basis/math/constants/constants.factor
@@ -8,6 +8,7 @@ IN: math.constants
 : phi ( -- phi ) 1.61803398874989484820 ; inline
 : pi ( -- pi ) 3.14159265358979323846 ; inline
 : 2pi ( -- pi ) 2 pi * ; inline
-: epsilon ( -- epsilon ) 2.2204460492503131e-16 ; inline
+: epsilon ( -- epsilon ) HEX: 3cb0000000000000 bits>double ; foldable
+: single-epsilon ( -- epsilon ) HEX: 34000000 bits>float ; foldable
 : smallest-float ( -- x ) HEX: 1 bits>double ; foldable
 : largest-float ( -- x ) HEX: 7fefffffffffffff bits>double ; foldable