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Re: lexing__get_next_char ?
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Date: -- (:)
From: Ian T Zimmerman <itz@r...>
Subject: Re: lexing__get_next_char ?


In article <199610211430.QAA11843@pauillac.inria.fr> Xavier Leroy
<Xavier.Leroy@inria.fr> writes:

> 
> > In the caml-light sources, in src/runtime/lexing.c, the primitive
> > get_next_char is defined as follows:
> > 
> > struct lexer_buffer {
> >   value refill_buff;
> >   value lex_buffer;
> >   value lex_abs_pos;
> >   value lex_start_pos;
> >   value lex_curr_pos;
> >   value lex_last_pos;
> >   value lex_last_action;
> > };
> > 
> > value get_next_char(lexbuf)     /* ML */
> >      struct lexer_buffer * lexbuf;
> > {
> >   mlsize_t buffer_len, curr_pos;
> >   
> >   buffer_len = string_length(lexbuf->lex_buffer);
> >      ...
> > 
> > How can this work, when lexer buffers are ML records on the heap, as
> > the following piece of src/lib/lexing.ml seems to show
> 
> Viewed from C, Caml records are arrays of elements of type "value".
> So, we're basically casting a pointer to a "value" array to a pointer 
> to a struct with all fields having type "value". 

But don't they have the header word in front??

-- 
Ian T Zimmerman                        <itz@rahul.net>
Days spent working only for oneself are twice wasted; 
it would have been better not to work at all.