mes/quasiquote.c
Jan Nieuwenhuizen 1614d13439 Add reader in Scheme.
* module/mes/read-0.mes: New file.
* mes.c (char_to_integer, integer_to_char, null_p): Move to core.
 (peek_byte, read_byte, unread_byte): New function.
 (main): --dump, --load: New option.
* lib.c (char_to_integer, integer_to_char): Remove.
* NEWS: Update.
2016-12-12 20:35:19 +01:00

119 lines
3 KiB
C

/* -*-comment-start: "//";comment-end:""-*-
* Mes --- Maxwell Equations of Software
* Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.org>
*
* This file is part of Mes.
*
* Mes is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* Mes is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Mes. If not, see <http://www.gnu.org/licenses/>.
*/
#if QUASIQUOTE
SCM
unquote (SCM x) ///((no-environment))
{
return cons (cell_symbol_unquote, x);
}
SCM
unquote_splicing (SCM x) ///((no-environment))
{
return cons (cell_symbol_unquote_splicing, x);
}
SCM
eval_quasiquote (SCM e, SCM a)
{
return vm_call (vm_eval_quasiquote, e, cell_undefined, a);
}
SCM
vm_eval_quasiquote ()
{
if (r1 == cell_nil) return r1;
else if (atom_p (r1) == cell_t) return r1;
else if (eq_p (car (r1), cell_symbol_unquote) == cell_t)
return eval_env (cadr (r1), r0);
else if (TYPE (r1) == PAIR && TYPE (car (r1)) == PAIR
&& eq_p (caar (r1), cell_symbol_unquote_splicing) == cell_t)
{
r2 = eval_env (cadar (r1), r0);
return append2 (r2, eval_quasiquote (cdr (r1), r0));
}
r2 = eval_quasiquote (car (r1), r0);
return cons (r2, eval_quasiquote (cdr (r1), r0));
}
SCM
add_unquoters (SCM a)
{
SCM q = assq_ref_cache (cell_symbol_the_unquoters, a);
return append2 (q, a);
}
#else // !QUASIQUOTE
SCM add_unquoters (SCM a){}
SCM eval_quasiquote (SCM e, SCM a){}
#endif // QUASIQUOTE
#if QUASISYNTAX
SCM
syntax (SCM x)
{
return cons (cell_symbol_syntax, x);
}
SCM
unsyntax (SCM x) ///((no-environment))
{
return cons (cell_symbol_unsyntax, x);
}
SCM
unsyntax_splicing (SCM x) ///((no-environment))
{
return cons (cell_symbol_unsyntax_splicing, x);
}
SCM
eval_quasisyntax (SCM e, SCM a)
{
if (e == cell_nil) return e;
else if (atom_p (e) == cell_t) return e;
else if (eq_p (car (e), cell_symbol_unsyntax) == cell_t)
return eval_env (cadr (e), a);
else if (TYPE (e) == PAIR && TYPE (car (e)) == PAIR
&& eq_p (caar (e), cell_symbol_unsyntax_splicing) == cell_t)
return append2 (eval_env (cadar (e), a), eval_quasisyntax (cdr (e), a));
return cons (eval_quasisyntax (car (e), a), eval_quasisyntax (cdr (e), a));
}
SCM
add_unsyntaxers (SCM a)
{
a = cons (cons (cell_symbol_unsyntax, cell_unsyntax), a);
a = cons (cons (cell_symbol_unsyntax_splicing, cell_unsyntax_splicing), a);
return a;
}
#else // !QUASISYNTAX
SCM syntax (SCM x){}
SCM unsyntax (SCM x){}
SCM unsyntax_splicing (SCM x){}
SCM add_unsyntaxers (SCM a){}
SCM eval_unsyntax (SCM e, SCM a){}
SCM eval_quasisyntax (SCM e, SCM a){}
#endif // !QUASISYNTAX