What causes a libmarpa rule step to have its argument list start at stack position -1?

2014-09-15 Thread Dylan Ede
I have just bumped into a situation where the valuator always produces a rule step that has arguments beginning from -1 for a particular rule. The rule is a sequence of 5 symbols, and is also the start rule. The first two are the same terminal symbol. marpa_v_arg_0 gives -1. marpa_v_arg_n gives

Re: What causes a libmarpa rule step to have its argument list start at stack position -1?

2014-09-15 Thread Ruslan Shvedov
Reading the libmarpa doc: the application must maintain the stack ensuring that it has the correct size for the valuation steps — http://jeffreykegler.github.io/Marpa-web-site/libmarpa_api/latest/Maintaining-the-stack.html#Maintaining-the-stack — hope this helps. On Mon, Sep 15, 2014 at 2:30 PM,

Re: What causes a libmarpa rule step to have its argument list start at stack position -1?

2014-09-15 Thread Dylan Ede
Just to clarify, the problem is that marpa_v_arg_0 returns -1, when the documentation explicitly specifies that it should never do so. On Monday, 15 September 2014 12:30:28 UTC+1, Dylan Ede wrote: I have just bumped into a situation where the valuator always produces a rule step that has