Re: Per-language project-search-path, was: Re: Unified project interface

[Eric Ludlam <ericludlam@gmail.com>]

On 08/02/2015 01:14 PM, Michael Heerdegen wrote:
> Nix <nix@esperi.org.uk> writes:
>
>> (What I'd really like is something like the el-search pcase-based
>> searcher Michael Heerdegen recently proposed, only for everything
>> supported by Semantic, but with most language grammars not being very
>> amenable to ML-style pattern-matching I doubt this is possible...)
> I agree that would be very useful.  But I don't know much about
> Semantic, and the info pages seem to be outdated.

Most of the doc is about using some of the user facing tools.  The 
sections about the lex stage should be good.

> Is there some function in semantic that parses the expression at point
> and returns a parse tree represented as (Lisp) list?  The outdated info
> page mentions ast.el which seems to do that, but I can't find it
> anymore.
>
> I guess one could try the following, more or less: go through the buffer
> and parse it on the fly to ast expressions.  The search command prompts
> for a "pattern" using the syntax of the buffer's language plus
> placeholders.  The input is parsed and converted to a an ast as well.
> Then the matching could be done in Elisp like el-search does.

You can use the lexer from semantic to get the list of parsed tokens.  
The current parsers output tags instead of an AST.  Making an AST would 
be handy for langauge sensitive tooling past tagging parsers, but would 
be a bit slow.  Large parts of the buffer aren't parsed at all right now 
as the parser skips over large { bracketed } blocks of code which keeps 
thing faster.

It may be that the specifics you are looking for are part of the local 
context parser, which includes functions such as -get-local-variables, 
-get-local-arguments, and -current-symbol, which gets the whole symbols 
in a dotted expression.   This is in semantic/ctxt.el.

Eric