From a7e883b206fc496d7c0faaf713bb7bdd91ff29d3 Mon Sep 17 00:00:00 2001
From: Tim Vaughan <tgvaughan@gmail.com>
Date: Sun, 11 Dec 2016 14:52:08 +1300
Subject: [PATCH] Added floating point printing words.

---
 src/float.4th | 153 +++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 139 insertions(+), 14 deletions(-)

diff --git a/src/float.4th b/src/float.4th
index c256da9..2305749 100644
--- a/src/float.4th
+++ b/src/float.4th
@@ -39,58 +39,183 @@ END-CODE
 CODE f>
     b = reinterpret(Float64, popPS())
     a = reinterpret(Float64, popPS())
-    pushPS(reinterpret(Int64, a>b))
+    if a > b
+        pushPS(-1)
+    else
+        pushPS(0)
+    end
 END-CODE
 
 CODE f<
     b = reinterpret(Float64, popPS())
     a = reinterpret(Float64, popPS())
-    pushPS(reinterpret(Int64, a<b))
+    if a < b
+        pushPS(-1)
+    else
+        pushPS(0)
+    end
 END-CODE
 
 CODE f=
     b = reinterpret(Float64, popPS())
     a = reinterpret(Float64, popPS())
-    pushPS(reinterpret(Int64, a=b))
+    if a == b
+        pushPS(-1)
+    else
+        pushPS(0)
+    end
 END-CODE
 
-CODE f<=
-    b = reinterpret(Float64, popPS())
-    a = reinterpret(Float64, popPS())
-    pushPS(reinterpret(Int64, a<=b))
-END-CODE
+: f<=
+    f> invert ;
 
-CODE f>=
+: f>=
+    f< invert ;
+
+CODE fmod
     b = reinterpret(Float64, popPS())
     a = reinterpret(Float64, popPS())
-    pushPS(reinterpret(Int64, a>=b))
+    pushPS(reinterpret(Int64, a%b))
 END-CODE
 
 CODE flog
-    b = reinterpret(Float64, popPS())
+    a = reinterpret(Float64, popPS())
     pushPS(reinterpret(Int64, log(a)))
 END-CODE
 
 CODE fexp
-    b = reinterpret(Float64, popPS())
+    a = reinterpret(Float64, popPS())
     pushPS(reinterpret(Int64, exp(a)))
 END-CODE
 
+CODE fnan?
+    a = reinterpret(Float64, popPS())
+    if isnan(a)
+        pushPS(-1)
+    else
+        pushPS(0)
+    end
+END-CODE
+
+CODE finf?
+    a = reinterpret(Float64, popPS())
+    if isinf(a)
+        pushPS(-1)
+    else
+        pushPS(0)
+    end
+END-CODE
+
 CODE i->f
     pushPS(reinterpret(Int64, Float64(popPS())))
 END-CODE
 
-: f.scientific ( float -- )
+CODE f->i
+    a = reinterpret(Float64, popPS())
+    pushPS(Int64(round(a)))
+END-CODE
+
+: f/mod
+    2dup fmod -rot f/ ;
+
+: 0.0
+    [ 0 i->f ] literal ;
+
+: 1.0
+    [ 1 i->f ] literal ;
+
+: -1.0
+    [ -1 i->f ] literal ;
+
+: 10.0
+    [ 10 i->f ] literal ;
+
+: flog10
+    flog [ 10 i->f flog ] literal f/ ;
+
+: fabs
+    dup 0.0 f< if
+        -1.0 f*
+    then
+;
+
+: floor
+    dup 0.0 f>= if
+        dup 1.0 fmod f-
+    else
+        dup 1.0 fmod dup 0.0 <> if
+            f- 1.0 f-
+        else
+            drop
+        then
+    then
 ;
 
+: fhead ( float -- )
+    floor f->i
+    0 .R  ;
+
+: ftail ( float prec -- )
+    dup 0<= if 2drop exit then
+
+    swap
+
+    1.0 fmod 10.0 f*
+
+    dup floor f->i 0 .R
+
+    1.0 fmod dup 0.0 f> if
+        swap 1- recurse
+    else
+        2drop
+    then
+;
+
+variable precision
+16 precision !
+
 : f.plain ( float -- )
 
+    dup 0.0 = if
+        ." 0.0"
+        drop exit
+    then
+
+    dup 0.0 f< if
+        [char] - emit
+        -1.0 f*
+    then
+
+    dup fhead
+
+    [char] . emit
+
+    precision @ over flog10 floor f->i -
+    ftail
+;
+
+: f.scientific ( float -- )
+    dup 0.0 = if
+        ." 0.0"
+        drop exit
+    then
+
+    dup 0.0 f< if
+        [char] - emit
+        -1.0 f*
+    then
+
+    dup flog10 floor dup -rot
+    10.0 swap f^ f/ f.plain
+    ." e" f->i 0 .R
 ;
 
 : f. ( float -- )
-    dup dup 1000000 i->f f>= swap 1 i->f 10000 i->f f/ f< or if
+    dup fabs dup 1000000 i->f f>= swap 1 i->f 10000 i->f f/ f< or if
         f.scientific
     else
         f.plain
     then
+
+    space
 ;
-- 
2.20.1