From: Neil Hodgson <nhodgson@...>
Date: 2001-04-20T08:10:06+09:00
Subject: [ruby-talk:13899] Re: A possible Ruby IDE. Help needed.

Guerry Semones:

> I downloaded SciTE from the Scintilla site (an editor that demonstrates
> Scintilla's capabilities).  Anyway, considering some of the notational /
> syntactical similarities between python and Ruby, there is already alot
> of the color-coding and code-folding that works.  I'm going to put up
> Ruby in Gvim with color-coding and compare to SciTE and see what's
> missing.  The LexPython.cxx file with Scintilla should/could be a
> starting point.

   The best starting point for a Ruby lexer is the C/C++/Java/... lexer
LexCPP, as it is based on the newer technique of separating the lexing
function from the folding function and the folder works on counting block
nesting level rather than on indentation as the Python folder does.

   I had a look at doing a Ruby lexer a while ago but was discouraged by
lexical complexity with regular expressions (disambiguating '/' used for
division from start of RE), strings with explicitly set delimiters, and here
documents and lack of time to handle these.

   Apart from LexCPP, LexPascal may help in examining keywords to determin
nesting. For the abovementioned problem areas, LexPerl is the only lexer
that does here documents properly (including stacked here documents) and
strings with explicit delimiters but LexPerl is big and complex so shouldn't
be read first as it will only serve to discourage.

   The technique used to disambiguate '/' in JavaScript used in LexCPP will
probably be good enoughfor Ruby.

   Neil