Re: [Boost-build] prototyping alternative Boost.Build syntax

Subject: Re: [Boost-build] prototyping alternative Boost.Build syntax
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2016-10-29 17:21:07

AMDG

On 10/29/2016 03:09 PM, Stefan Seefeld wrote:
> On 29.10.2016 16:50, Steven Watanabe wrote:
>>> * The bjam.define_action() function takes a list and an int as third and
>>> fourth argument. What are these used for ?
>>>
>>   The list is a list of variable names.
>> The variable names should be a list of
>> targets which will be translated from
>> the target name to the filesystem path.
>>
>> Example:
>>
>> actions link bind LIBRARIES {
>>   g++ $(>) -o $(<) $(LIBRARIES)
>> }
> 
> I see. So '>' and '<' are pre-defined variables ?

  Yes.  They are handled in the same way as the
bindlist.

> Are there other
> predefined variables beside those ?

  $(<) and $(>) are synonyms for $(1) and $(2).
($(n) is the nth argument of a rule up to 19.)
Only these two variables get special handling
in an action body and they are not treated
specially in any other context.

> (Where in the code does the expansion happen ?)
> 

I don't understand the question.

In Christ,
Steven Watanabe