[clean-list] Re: Advice on style, please

[alanh@dcs.kcl.ac.uk]

Many thanks to Richard and Fergus, particularly to Fergus for real help
with my C code.  Please excuse my blunders.  They were committed late
in the evening, when I should have been in bed.

Please erase that example.  It is a defamation of the Clean language.
The problem can be solved substantially better, e.g. as below.
Regards
Alan H.

module copy
import StdEnv
import ArgEnv

Start :: *World -> *World

Start w0
| argc <> 3  =  snd (fclose (console1 <<< "Usage:\nCopy <input file> <output file>\n") w1)
| not fiOK   =  snd (fclose (console1 <<< ("Can't open file " +++ argv.[1] +++ "\n")) w2)
| not foOK   =  snd (fclose (console1 <<< ("Can't open file " +++ argv.[2] +++ "\n")) w3)
| not ccOK   =  snd (fclose (console1 <<< "failed.\n") w4)
| otherwise  =  snd (fclose console1 w4)
where
  (console1, w1)    =  stdio w0
  argv              =  getCommandLine
  argc              =  size argv
  (fiOK, fi0, w2)   =  fopen argv.[1] FReadText w1
  (foOK, fo0, w3)   =  fopen argv.[2] FWriteText w2
  (ccOK, fi1, fo1)  =  cc (fi0,fo0)

  w4  =  (snd (fclose fo1 (snd (fclose fi1 w3))))

cc :: (*File, *File) -> (Bool, *File, *File)
cc (fi0,fo0)
| atEnd      =  (True,  fia, fo0)
| not ok     =  (False, fi1, fo0)
| err        =  (False, fi1, fo1)
| otherwise  =  cc (fi1,fo1)
where
  (atEnd, fia)  =  fend fi0
  (ok, c, fi1)  =  freadc fia
  (err,fo1)     =  ferror (fwritec c fo0)