From: Brian H. <bri...@ql...> - 2003-03-20 17:17:21
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Opps. Too late :-) Brian ---------- Forwarded message ---------- Date: 21 Mar 2003 01:50:36 +0900 From: Yutaka OIWA <oi...@yl...> To: cam...@in... Subject: [Caml-list] Announce: Regexp/OCaml syntax extension Hello subscribers: I release a camlp4-macro package called Regexp/OCaml. I believe Objective Caml is a powerful tool not only for writing an interpreter and compiler but also for writing casual "script" applications which were in a territory of Perl, Python and Ruby. However, string decomposition is one of OCaml's weak points when compared to those scripting languages: the interfaces of both Str module and Pcre module are very primitive and cumbersome if they are heavily used. Regexp/OCaml solves this point by providing syntax support for regular expression matching. Regexp/OCaml provides convenient syntax sugar for regular expression match against strings using PCRE/OCaml library. The features of this macro package are the following: * Convenient syntax: similar to standard match-with expressions * Binding matching substrings to variables: no more $1, $2, ... * Automagical easy-to-use type-coercion: no flood of int_of_string etc. * Support for optional-patterns: gives string option type etc. * Default values for optional-patterns For example, parsing an entry for some log file becomes as easy as follows: try while true do let line = input_line ic in Regexp.match line with "^\((\d\d):(\d\d):(\d\d)\)\[(.*?)\] (.*)$" as hour : int, min: int, sec : int, name, line -> let time = hour * 3600 + min * 60 + sec in ... | "^# (.*)$" as meta_info -> ... | _ -> () done with End_of_file -> () This short code parses both line in format like "(00:34:32) [foobar] something" and "# some meta info" and binds appropriate data into variables which can be used inside "...". Compare the code above with an equivalent without using syntax extension. Regexp/OCaml is downloadable from the web location http://www.yl.is.s.u-tokyo.ac.jp/~oiwa/caml/ . In addition to the main macro called pa_regexp_match, the package also contains two tiny macros: 1) pa_pragma changes an option for loaded camlp4 macros inside source code. 2) pa_once provides "once" construct which evaluates any expression only once per execution (pa_regexp_match uses this internally). Any comments will be greatly appreciated. -- Yutaka Oiwa Yonezawa Lab., Dept. of Computer Science, Graduate School of Information Sci. & Tech., Univ. of Tokyo. <oi...@yl...>, <yu...@oi...> PGP fingerprint = C9 8D 5C B8 86 ED D8 07 EA 59 34 D8 F4 65 53 61 ------------------- To unsubscribe, mail cam...@in... Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners |