Difference between revisions of "Programming performance/JasonWoof gforth"

Programming language: gforth (should work in other forths too)

Experience level with language: quite a bit. I only had to look up a few things

Time spent: 102 minutes

Notes:

1) I implemented this problem once before in ruby (Don't think that helped too much though. The two languages have little in common.)

2) I wrote this from scratch, including a number parser and array/list code. In the real world one would hopefully already have code for these things.

3) This program expects gspc.txt to come through on stdin, so run like so: gforth jasonwoof_gspc.fs < gspc.txt

<pre>

#! /usr/bin/gforth

warnings off

fvariable bank 10000e bank f!

: p>f s>d d>f 100e f/ ; ( pennies -- float )

\ make a FOR that makes sense, and can take 0 as count, and UNLOOP

: for 0 postpone literal postpone ?do ; immediate

: next postpone loop ; immediate

: ++ 1 swap +! ; ( var -- )

: -- -1 swap +! ; ( var -- )

\ kill the header

: dump-line key 10 = if exit then recurse ;

dump-line

: dump-word key 32 = if exit then recurse ;

: dump-others 6 for dump-word next ;

variable #fields

variable last-field

: field-pop last-field @ 4 - dup last-field ! @ ; ( -- field ) \ return the next field

: -parse-close key dup 10 = if drop exit then dup [char] . = if drop recurse exit then 48 - swap 10 * + recurse ;

: parse-close 0 -parse-close ; ( -- pennies ) \ parse digits until end of line (ignoring decimal point)

: parse-field dump-others parse-close , #fields ++ ; ( -- )

: parse-fields begin key -1 = if exit then parse-field again ;

parse-fields

here last-field !

fvariable last-close

fvariable close

fvariable sell-thresh

\ initialize close

field-pop p>f close f!

#fields @ 1 - #fields !

variable #holds

create holds 1000 floats allot

: hold-close-a 2 * floats holds + ;

: hold-last-a #holds @ hold-close-a ;

: hold-last-close! hold-last-a f! ;

: hold-last-shares! hold-last-a float+ f! ;

: hold-close@ hold-close-a f@ ;

: hold-shares@ hold-close-a float+ f@ ;

: hold-push hold-last-shares! close f@ hold-last-close! #holds ++ ; ( #shares -- )

: hold-cleanup #holds @ dup for 1 - dup hold-close@ f0= 0= if unloop drop exit then #holds -- next drop ;

: get-close close f@ last-close f! field-pop p>f close f! ; ( -- )

: change close f@ last-close f@ f- last-close f@ f/ ; ( -- % )

: withdraw bank f@ 10e f/ bank f@ fover f- bank f! ; ( -- cash )

: deposit bank f@ f+ bank f! ; ( money -- )

: buy withdraw close f@ f/ hold-push ;

: ?buy change -0.03e f< if buy then ;

: hold-sell dup float+ f@ close f@ f* deposit >r 0e r> f! ; ( addr -- )

: -?hold-sell dup f@ sell-thresh f@ f> if drop exit then hold-sell ; ( addr -- )

: ?hold-sell dup f@ f0= if drop exit then -?hold-sell ; ( addr -- )

: set-sell-thresh close f@ 1.06e f/ sell-thresh f! ;

: -sell #holds @ for i hold-close-a ?hold-sell next ;

: sell set-sell-thresh -sell hold-cleanup ;

: trade #fields @ for get-close ?buy sell next ;

: sell-all 100000e sell-thresh f! -sell ;

trade

sell-all

bank f@ f. cr bye

</pre>