diff options
Diffstat (limited to 'src/lisp/ao_lisp_lambda.c')
| -rw-r--r-- | src/lisp/ao_lisp_lambda.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/src/lisp/ao_lisp_lambda.c b/src/lisp/ao_lisp_lambda.c new file mode 100644 index 00000000..cc5af4bc --- /dev/null +++ b/src/lisp/ao_lisp_lambda.c @@ -0,0 +1,188 @@ +/* + * Copyright © 2016 Keith Packard <keithp@keithp.com> + * + * This program 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; version 2 of the License. + * + * This program 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 this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + */ + +#define DBG_EVAL 0 +#include "ao_lisp.h" + +int +lambda_size(void *addr) +{ + (void) addr; + return sizeof (struct ao_lisp_lambda); +} + +void +lambda_mark(void *addr) +{ + struct ao_lisp_lambda *lambda = addr; + + ao_lisp_poly_mark(lambda->code, 0); + ao_lisp_poly_mark(lambda->frame, 0); +} + +void +lambda_move(void *addr) +{ + struct ao_lisp_lambda *lambda = addr; + + ao_lisp_poly_move(&lambda->code, 0); + ao_lisp_poly_move(&lambda->frame, 0); +} + +const struct ao_lisp_type ao_lisp_lambda_type = { + .size = lambda_size, + .mark = lambda_mark, + .move = lambda_move, +}; + +static int +ao_lisp_cons_length(struct ao_lisp_cons *cons) +{ + int len = 0; + while (cons) { + len++; + cons = ao_lisp_poly_cons(cons->cdr); + } + return len; +} + +void +ao_lisp_lambda_print(ao_poly poly) +{ + struct ao_lisp_lambda *lambda = ao_lisp_poly_lambda(poly); + struct ao_lisp_cons *cons = ao_lisp_poly_cons(lambda->code); + + printf("("); + printf("%s", ao_lisp_args_name(lambda->args)); + while (cons) { + printf(" "); + ao_lisp_poly_print(cons->car); + cons = ao_lisp_poly_cons(cons->cdr); + } + printf(")"); +} + +ao_poly +ao_lisp_lambda_alloc(struct ao_lisp_cons *code, int args) +{ + struct ao_lisp_lambda *lambda = ao_lisp_alloc(sizeof (struct ao_lisp_lambda)); + struct ao_lisp_cons *arg; + int f; + + if (!lambda) + return AO_LISP_NIL; + + if (!ao_lisp_check_argc(_ao_lisp_atom_lambda, code, 2, 2)) + return AO_LISP_NIL; + if (!ao_lisp_check_argt(_ao_lisp_atom_lambda, code, 0, AO_LISP_CONS, 1)) + return AO_LISP_NIL; + f = 0; + arg = ao_lisp_poly_cons(ao_lisp_arg(code, 0)); + while (arg) { + if (ao_lisp_poly_type(arg->car) != AO_LISP_ATOM) + return ao_lisp_error(AO_LISP_INVALID, "formal %d is not an atom", f); + arg = ao_lisp_poly_cons(arg->cdr); + f++; + } + + lambda->type = AO_LISP_LAMBDA; + lambda->args = args; + lambda->code = ao_lisp_cons_poly(code); + lambda->frame = ao_lisp_frame_poly(ao_lisp_frame_current); + DBGI("build frame: "); DBG_POLY(lambda->frame); DBG("\n"); + DBG_STACK(); + return ao_lisp_lambda_poly(lambda); +} + +ao_poly +ao_lisp_lambda(struct ao_lisp_cons *cons) +{ + return ao_lisp_lambda_alloc(cons, AO_LISP_FUNC_LAMBDA); +} + +ao_poly +ao_lisp_lexpr(struct ao_lisp_cons *cons) +{ + return ao_lisp_lambda_alloc(cons, AO_LISP_FUNC_LEXPR); +} + +ao_poly +ao_lisp_nlambda(struct ao_lisp_cons *cons) +{ + return ao_lisp_lambda_alloc(cons, AO_LISP_FUNC_NLAMBDA); +} + +ao_poly +ao_lisp_macro(struct ao_lisp_cons *cons) +{ + return ao_lisp_lambda_alloc(cons, AO_LISP_FUNC_MACRO); +} + +ao_poly +ao_lisp_lambda_eval(struct ao_lisp_lambda *lambda, + struct ao_lisp_cons *cons) +{ + struct ao_lisp_cons *code; + struct ao_lisp_cons *args; + struct ao_lisp_frame *next_frame; + int args_wanted; + int args_provided; + + code = ao_lisp_poly_cons(lambda->code); + DBGI("lambda "); DBG_POLY(ao_lisp_lambda_poly(lambda)); DBG("\n"); + args = ao_lisp_poly_cons(ao_lisp_arg(code, 0)); + + args_wanted = ao_lisp_cons_length(args); + + /* Create a frame to hold the variables + */ + if (lambda->args == AO_LISP_FUNC_LAMBDA) + args_provided = ao_lisp_cons_length(cons) - 1; + else + args_provided = 1; + if (args_wanted != args_provided) + return ao_lisp_error(AO_LISP_INVALID, "need %d args, not %d", args_wanted, args_provided); + next_frame = ao_lisp_frame_new(args_wanted); + switch (lambda->args) { + case AO_LISP_FUNC_LAMBDA: { + int f; + struct ao_lisp_cons *vals = ao_lisp_poly_cons(cons->cdr); + + for (f = 0; f < args_wanted; f++) { + DBGI("bind "); DBG_POLY(args->car); DBG(" = "); DBG_POLY(vals->car); DBG("\n"); + next_frame->vals[f].atom = args->car; + next_frame->vals[f].val = vals->car; + args = ao_lisp_poly_cons(args->cdr); + vals = ao_lisp_poly_cons(vals->cdr); + } + break; + } + case AO_LISP_FUNC_LEXPR: + case AO_LISP_FUNC_NLAMBDA: + case AO_LISP_FUNC_MACRO: + DBGI("bind "); DBG_POLY(args->car); DBG(" = "); DBG_POLY(cons->cdr); DBG("\n"); + next_frame->vals[0].atom = args->car; + next_frame->vals[0].val = cons->cdr; + break; + } + next_frame->next = lambda->frame; + DBGI("eval frame: "); DBG_POLY(ao_lisp_frame_poly(next_frame)); DBG("\n"); + ao_lisp_frame_current = next_frame; + ao_lisp_stack->frame = ao_lisp_frame_poly(ao_lisp_frame_current); + DBG_STACK(); + return ao_lisp_arg(code, 1); +} |