diff options
Diffstat (limited to 'src/scheme/ao_scheme_atom.c')
| -rw-r--r-- | src/scheme/ao_scheme_atom.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/src/scheme/ao_scheme_atom.c b/src/scheme/ao_scheme_atom.c new file mode 100644 index 00000000..cb32b7fe --- /dev/null +++ b/src/scheme/ao_scheme_atom.c @@ -0,0 +1,167 @@ +/* + * 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. + */ + +#include "ao_scheme.h" + +static int name_size(char *name) +{ + return sizeof(struct ao_scheme_atom) + strlen(name) + 1; +} + +static int atom_size(void *addr) +{ + struct ao_scheme_atom *atom = addr; + if (!atom) + return 0; + return name_size(atom->name); +} + +static void atom_mark(void *addr) +{ + struct ao_scheme_atom *atom = addr; + + for (;;) { + atom = ao_scheme_poly_atom(atom->next); + if (!atom) + break; + if (ao_scheme_mark_memory(&ao_scheme_atom_type, atom)) + break; + } +} + +static void atom_move(void *addr) +{ + struct ao_scheme_atom *atom = addr; + int ret; + + for (;;) { + struct ao_scheme_atom *next = ao_scheme_poly_atom(atom->next); + + if (!next) + break; + ret = ao_scheme_move_memory(&ao_scheme_atom_type, (void **) &next); + if (next != ao_scheme_poly_atom(atom->next)) + atom->next = ao_scheme_atom_poly(next); + if (ret) + break; + atom = next; + } +} + +const struct ao_scheme_type ao_scheme_atom_type = { + .mark = atom_mark, + .size = atom_size, + .move = atom_move, + .name = "atom" +}; + +struct ao_scheme_atom *ao_scheme_atoms; + +struct ao_scheme_atom * +ao_scheme_atom_intern(char *name) +{ + struct ao_scheme_atom *atom; + + for (atom = ao_scheme_atoms; atom; atom = ao_scheme_poly_atom(atom->next)) { + if (!strcmp(atom->name, name)) + return atom; + } +#ifdef ao_builtin_atoms + for (atom = ao_scheme_poly_atom(ao_builtin_atoms); atom; atom = ao_scheme_poly_atom(atom->next)) { + if (!strcmp(atom->name, name)) + return atom; + } +#endif + ao_scheme_string_stash(0, name); + atom = ao_scheme_alloc(name_size(name)); + name = ao_scheme_string_fetch(0); + if (atom) { + atom->type = AO_SCHEME_ATOM; + atom->next = ao_scheme_atom_poly(ao_scheme_atoms); + ao_scheme_atoms = atom; + strcpy(atom->name, name); + } + return atom; +} + +ao_poly * +ao_scheme_atom_ref(ao_poly atom, struct ao_scheme_frame **frame_ref) +{ + ao_poly *ref; + struct ao_scheme_frame *frame; + + for (frame = ao_scheme_frame_current; frame; frame = ao_scheme_poly_frame(frame->prev)) { + ref = ao_scheme_frame_ref(frame, atom); + if (ref) { + if (frame_ref) + *frame_ref = frame; + return ref; + } + } + ref = ao_scheme_frame_ref(ao_scheme_frame_global, atom); + if (ref) + if (frame_ref) + *frame_ref = ao_scheme_frame_global; + return ref; +} + +ao_poly +ao_scheme_atom_get(ao_poly atom) +{ + ao_poly *ref = ao_scheme_atom_ref(atom, NULL); + +#ifdef ao_builtin_frame + if (!ref) + ref = ao_scheme_frame_ref(ao_scheme_poly_frame(ao_builtin_frame), atom); +#endif + if (ref) + return *ref; + return ao_scheme_error(AO_SCHEME_UNDEFINED, "undefined atom %s", ao_scheme_poly_atom(atom)->name); +} + +ao_poly +ao_scheme_atom_set(ao_poly atom, ao_poly val) +{ + ao_poly *ref = ao_scheme_atom_ref(atom, NULL); + + if (!ref) + return ao_scheme_error(AO_SCHEME_UNDEFINED, "undefined atom %s", ao_scheme_poly_atom(atom)->name); + *ref = val; + return val; +} + +ao_poly +ao_scheme_atom_def(ao_poly atom, ao_poly val) +{ + struct ao_scheme_frame *frame; + ao_poly *ref = ao_scheme_atom_ref(atom, &frame); + + if (ref) { + if (frame == ao_scheme_frame_current) + return ao_scheme_error(AO_SCHEME_REDEFINED, "attempt to redefine atom %s", ao_scheme_poly_atom(atom)->name); + *ref = val; + return val; + } + return ao_scheme_frame_add(ao_scheme_frame_current ? ao_scheme_frame_current : ao_scheme_frame_global, atom, val); +} + +void +ao_scheme_atom_write(ao_poly a) +{ + struct ao_scheme_atom *atom = ao_scheme_poly_atom(a); + printf("%s", atom->name); +} |