Re: spend a lot of time with alex generated module

Malcolm Wallace wrote:

kgu kguento@... wrote:

  

hat-trans spends a lot of time (really a lot of time) in generate
module from a module generated by alex. The original module has 330
lines of code and module generated by hat-trans has 40700 !!.
    

It is well-known that giving a machine-generated input to any
compiler-like tool is the best way to show up its weaknesses!  I suppose
the output from Alex is very different from the kind of code that a
human would write.  Since Alex creates essentially a table-driven
lexical analyser, it is possible that a large static description of the
tables is where hat-trans is spending lots of time.  Also, if the
Alex-generated code is deeply nested, hat-trans may spend too much time
trying to pretty-print its output within 80 columns, when really the
formatting will not fit nicely into such a small width.

Just some ideas.  If you want to send a copy of the original Alex
specification, we may be able to investigate further.

Regards,
    Malcolm
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I attach original specification.It's a very simple lexer specification. I had  some problem to compile module generated by hat-trans , it spends a lot of time too and it did not compile.

Thanks for your help and your job, i'm developing a compiler and hat is a really useful tool for me, it's a great tool!

Thanks,
Iván




{
module Lexer (Token(..), alexScanTokens) where
}

%wrapper "basic"

$digit = 0-9                    -- digits
$alpha = [a-zA-Z]               -- alphabetic characters

tokens :-
 
  $white+            ;
  "--".*             ;
  \.                { \s -> TPUNTO }
  \)                { \s -> TPARDER }
  \(                { \s -> TPARIZQ }
  \[                { \s -> TCORIZQ }
  \]                { \s -> TCORDER }
  \|                { \s -> TPIPE }
  =                { \s -> TIGUAL }
  !=               { \s -> TDISTINTO }
  "->"                 { \s -> TFLECHA }
  >                { \s -> TMAYOR }
  >=               { \s -> TMAYORIGUAL }
  \<                { \s -> TMENOR }
  \<=               { \s -> TMENORIGUAL }
  \+               { \s -> TMAS }
  \-                { \s -> TMENOS }
  \*               { \s -> TPOR }
  \/                 { \s -> TBARRA }
  &                  { \s -> TAND }
  \^                 { \s -> TTILDE }
  \,                { \s -> TCOMA }
  \;                { \s -> TPUNTOCOMA }
  :=                 { \s -> TDOSIGUAL }
  ::                 { \s -> TCUATROPUNTOS }
  \;\;                 { \s -> TDOSPUNTOCOMA }
  :                { \s -> TDOSPUNTOS }
  []                 { \s -> TCORCHETES }
  null               { \s -> TNULL }
  Int                { \s -> TINT }
  String             { \s -> TSTRING }
  in                 { \s -> TIN }
  let                { \s -> TLET }
  rec                { \s -> TISREC }
  case               { \s -> TCASE }
  of                 { \s -> TOF }
  if                 { \s -> TIF }
  then               { \s -> TTHEN }
  else               { \s -> TELSE }
  "\""['A'-'Z''a'-'z''0'-'9''_'' ']* "\""
                     {  \s -> TCADENA s }
  $digit+            {  \s -> TENTERO (read s) }
  $alpha [$alpha $digit \_ \']*
                     { \s -> TVAR s }

  eof                {  \s -> TEOF }
 
{  
data Token
        = TBLANCO
        | TCOMMENT
  | TPUNTO
    | TPARIZQ
    | TPARDER
    | TCORIZQ
    | TCORDER
    | TPIPE  
        | TAMBER
    | TIGUAL
        | TDISTINTO
    | TFLECHA
    | TMAYOR
        | TMAYORIGUAL
    | TMENOR
        | TMENORIGUAL
    | TMAS
    | TMENOS
    | TPOR
    | TBARRA
    | TTILDE
    | TCOMA
  | TPUNTOCOMA
    | TDOSIGUAL
    | TCUATROPUNTOS
    | TDOSPUNTOCOMA
    | TDOSPUNTOS
    | TCORCHETES
        | TNULL
    | TAND
    | TINT
    | TSTRING
    | TIN
    | TLET
    | TISREC
    | TCASE
    | TOF
    | TIF
        | TTHEN
        | TELSE
        | TCADENA String
    | TENTERO Int
    | TVAR String
    | TEOF
        deriving (Eq,Show)

}
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