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| Date: | -- (:) |
| From: | Jean-Christophe Filliatre <Jean-Christophe.Filliatre@l...> |
| Subject: | Re: [Caml-list] Pattern match floats |
George Russell writes:
> I am working through the OReilly book and have got as far as working on
> the little basic interpreter. I Am adding support for float type
> variables, and am trying to modify the lexer.
>
> I would like to be able to match ('0'..'9')*'.'('0'..'9')* i.e. one or
> more digits, a period, followed bt one or more digits.
>
> I can't see how to do this in OCaml patter matching? Any ideas?
In ocamllex, such a regular expression is written
['0'-'9']* '.' ['0'-'9']* { your action, probably using
(float_of_string (lexeme lexbuf) }
Another remark: you write "one or more digits" but you are using the
star operation i.e. "zero, one or more digits".
Hope this helps,
--
Jean-Christophe Filliatre (http://www.lri.fr/~filliatr)
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