Re: [Gnu-arch-users] [BUG] FEATURE PLANS: selection by ID

[Bug Goo]

Created as bug 128

On Tue May 25 01:45:05 2004, Tom Lord wrote:
> 
> 
> The little language for expressing tree selections was introduced in
> the last message.  This message extends it, slighly.
> 
> We've seen rules of the form:
> 
>       (<outcome> <location>)
> 
> where if the <location> matches or matches a prefix of the location of
> the item being tested, then the <outcome> specifies the result
> produced by this rule.
> 
> So far, we've written all rule patterns just as strings, specifying a
> location:
> 
>       (b "./include/X11/x.h")
> 
> Such rules can be written using a list path fragments instead of a
> single string:
> 
>       (b ("./include" "X11" "x.h"))
> 
> or 
> 
>       (b ("./include/X11" "x.h"))
> 
> etc.
> 
> Any string in a rule pattern can be replaced with a list of the form:
> 
>       (id STRING)
> 
> Before a set of rules is evaluated for a given tree, all "(id STRING)" 
> elements in patterns are replaced by suitably pruned paths.
> 
> For example, suppose that we have the rule:
> 
>       (b ("./include" (id "i_x_header_file")))
> 
> Suppose that in the tree we're looking at, the file with the id
> "i_x_header_file" is at the path:  "./include/X11/basic/x.h".
> Then the rule is rewritten:
> 
>       (b ("./include" "X11/basic/x.h"))
> 
> and is therefore equivalent to:
> 
>       (b "./include/X11/basic/x.h)
> 
> If a rule references an inventory id that doesn't exist, the rule is
> simply discarded -- it matches nothing.
> 
> -t
> 
> 
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