retroforth/interfaces/io/io_floatingpoint.forth
crc eb5e7c9e0a floating point: add f:sign
FossilOrigin-Name: f2acb2926863ce13becc2139492247f8d11c119c1dac47173105c610bec3488c
2019-02-20 03:36:22 +00:00

150 lines
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Forth

~~~
{{
'io:FloatingPoint var
:identify
@io:FloatingPoint n:zero? [
#2 io:scan-for dup n:negative?
[ drop 'IO_DEVICE_TYPE_0002_NOT_FOUND s:put nl ]
[ !io:FloatingPoint ] choose ] if ;
---reveal---
:io:float-operation identify @io:FloatingPoint io:invoke ;
}}
~~~
# Floating Point
~~~
:n:to-float (n-_f:-n) #0 io:float-operation ;
:s:to-float (s-_f:-n) #1 io:float-operation ;
:f:to-number (f:a-__-n) #2 io:float-operation ;
:f:to-string (f:n-__-s) s:empty dup #3 io:float-operation ;
:f:+ (f:ab-c) #4 io:float-operation ;
:f:- (f:ab-c) #5 io:float-operation ;
:f:* (f:ab-c) #6 io:float-operation ;
:f:/ (f:ab-c) #7 io:float-operation ;
:f:floor (f:ab-c) #8 io:float-operation ;
:f:ceiling (f:f-f) #9 io:float-operation ;
:f:sqrt (f:f-f) #10 io:float-operation ;
:f:eq? (f:ab-c) #11 io:float-operation ;
:f:-eq? (f:ab-c) #12 io:float-operation ;
:f:lt? (f:ab-c) #13 io:float-operation ;
:f:gt? (f:ab-c) #14 io:float-operation ;
:f:depth (-n) #15 io:float-operation ;
:f:dup (f:a-aa) #16 io:float-operation ;
:f:drop (f:a-) #17 io:float-operation ;
:f:swap (f:ab-ba) #18 io:float-operation ;
:f:log (f:ab-c) #19 io:float-operation ;
:f:power (f:ab-c) #20 io:float-operation ;
:f:sin (f:f-f) #21 io:float-operation ;
:f:cos (f:f-f) #22 io:float-operation ;
:f:tan (f:f-f) #23 io:float-operation ;
:f:asin (f:f-f) #24 io:float-operation ;
:f:acos (f:f-f) #25 io:float-operation ;
:f:atan (f:f-f) #26 io:float-operation ;
:f:push (f:f-) #27 io:float-operation ;
:f:pop (f:-f) #28 io:float-operation ;
:f:square (f:n-m) f:dup f:* ;
:f:over (f:ab-aba) f:push f:dup f:pop f:swap ;
:f:tuck (f:ab-bab) f:dup f:push f:swap f:pop ;
:f:nip (f:ab-b) f:swap f:drop ;
:f:drop-pair (f:ab-) f:drop f:drop ;
:f:dup-pair (f:ab-abab) f:over f:over ;
:f:rot (f:abc-bca) f:push f:swap f:pop f:swap ;
:f:positive? (-f__f:a-) #0 n:to-float f:gt? ;
:f:negative? (-f__f:a-) #0 n:to-float f:lt? ;
:f:negate (f:a-b) #-1 n:to-float f:* ;
:f:abs (f:a-b) f:dup f:negative? [ f:negate ] if ;
:prefix:. (s-__f:-a)
compiling? [ s:keep ] [ s:temp ] choose &s:to-float class:word ; immediate
:f:put (f:a-) f:to-string s:put ;
:f:PI (f:-F) .3.141592 ;
:f:E (f:-F) .2.718281 ;
:f:NAN (f:-n) .0 .0 f:/ ;
:f:INF (f:-n) .1.0 .0 f:/ ;
:f:-INF (f:-n) .-1.0 .0 f:/ ;
:f:nan? (f:n-,-f) f:dup f:-eq? ;
:f:inf? (f:n-,-f) f:INF f:eq? ;
:f:-inf? (f:n-,-f) f:-INF f:eq? ;
:f:round (-|f:a-b)
f:dup f:negative?
[ .0.5 f:- f:ceiling ]
[ .0.5 f:+ f:floor ] choose ;
:f:min (f:nn-n) f:dup-pair f:lt? &f:drop &f:nip choose ;
:f:max (f:nn-n) f:dup-pair f:gt? &f:drop &f:nip choose ;
:f:limit (f:nlu-n) f:swap f:push f:min f:pop f:max ;
:f:between? (f:nlu-n) f:rot f:dup f:push f:rot f:rot f:limit f:pop f:eq? ;
:f:inc (f:n-n) .1 f:+ ;
:f:dec (f:n-n) .1 f:- ;
:f:case (f:ff-,q-)
f:over f:eq? [ f:drop call #-1 ] [ drop #0 ] choose 0; pop drop-pair ;
:f:sign (-n|f:a-)
f:dup .0 f:eq? [ #0 f:drop ] if;
.0 f:gt? [ #1 ] [ #-1 ] choose ;
~~~
---------------------------------------------------------------
# Float
## Description
This implements a means of encoding floating point values into signed integer cells. The technique is described in the paper titled "Encoding floating point numbers to shorter integers" by Kiyoshi Yoneda and Charles Childers.
This will extend the `f:` vocabulary and adds a new `u:` vocabulary.
## Code & Commentary
Define some constants. The range is slightly reduced from the standard integer range as the smallest value is used for NaN.
~~~
n:MAX n:dec 'u:MAX const
n:MAX n:dec n:negate 'u:MIN const
n:MIN 'u:NAN const
n:MAX 'u:INF const
n:MAX n:negate 'u:-INF const
~~~
~~~
:u:n? (u-f)
u:MIN n:inc u:MAX n:dec n:between? ;
:u:max? (u-f) u:MAX eq? ;
:u:min? (u-f) u:MIN eq? ;
:u:zero? (u-f) n:zero? ;
:u:nan? (u-f) u:NAN eq? ;
:u:inf? (u-f) u:INF eq? ;
:u:-inf? (u-f) u:-INF eq? ;
:u:clip (u-u) u:MIN u:MAX n:limit ;
~~~
~~~
:u:scaling hook .10.0e-4 ;
{{
:f:encode .0.5 f:power u:scaling .-1.0 f:power f:* ;
:f:decode f:square u:scaling f:square f:* ;
---reveal---
:f:to-u (-u|f:a-)
f:dup f:encode f:round f:to-number u:clip
f:dup f:nan? [ drop u:NAN ] if
f:dup f:inf? [ drop u:INF ] if
f:dup f:-inf? [ drop u:-INF ] if
f:drop ;
:u:to-f (u-|f:-b)
dup n:to-float f:decode
dup u:nan? [ f:drop f:NAN ] if
dup u:inf? [ f:drop f:INF ] if
dup u:-inf? [ f:drop f:-INF ] if
drop ;
}}
~~~
~~~
:f:store (a-|f:n-) [ f:to-u ] dip store ;
:f:fetch (a-|f:-n) fetch u:to-f ;
~~~
~~~
:f:dump-stack f:depth dup [ f:push ] times [ f:pop f:dup f:put sp ] times ;
~~~