Files
glisp/src/function.c
T
2026-07-18 22:31:01 -07:00

555 lines
18 KiB
C

#include "function.h"
#include "hashtable.h"
#include "lisp.h"
#include "list.h"
#include "read.h"
#include "stack.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
const char *llps_strerror(LambdaListParseStatus status) {
static const char *MSGS[LLPS_N_ERROS] = {
[LLPS_OK] = "No error",
[LLPS_DOTTED] = "Dotted list",
[LLPS_REPEAT_SECTION] = "Repeated section",
[LLPS_REPEAT_NAME] = "Repeated name",
[LLPS_ORDER] = "Section out of order",
[LLPS_BAD_NAME] = "Invalid variable name",
[LLPS_REPEAT_REST] = "Too many rest variables",
[LLPS_AFTER_ALLOW_OTHER_KEYS] = "Variable after &allow-other-keys",
[LLPS_INVALID_OPT_SPEC] = "Invalid optional spec",
};
return MSGS[status];
}
DEFINE_SYMBOL(and_optional, "&optional");
DEFINE_SYMBOL(and_rest, "&rest");
DEFINE_SYMBOL(and_key, "&key");
DEFINE_SYMBOL(and_allow_other_keys, "&allow-other-keys");
static bool is_valid_variable_name(LispVal *val) {
return SYMBOLP(val) && !NILP(val) && val != Qt && val != Qunbound;
}
static LispVal *intern_as_keyword(LispVal *name) {
assert(SYMBOLP(name));
LispString *name_str = ((LispSymbol *) name)->name;
char *kw_name = lisp_malloc(name_str->length + 2);
kw_name[0] = ':';
memcpy(kw_name + 1, name_str->data, name_str->length);
kw_name[name_str->length + 1] = '\0';
return Fintern(
make_lisp_string(kw_name, name_str->length + 1, true, false));
}
// on error, put the object that caused the problem in entry
static LambdaListParseStatus
parse_optional_arg_spec(LispVal *used_names, LispVal **out, LispVal *entry) {
// single symbol
if (SYMBOLP(entry)) {
if (!is_valid_variable_name(entry)) {
*out = entry;
return LLPS_BAD_NAME;
} else if (!NILP(Fgethash(used_names, entry, Qnil))) {
*out = entry;
return LLPS_REPEAT_NAME;
}
*out = LIST(entry, Qnil, Qnil);
Fputhash(used_names, entry, Qt);
return LLPS_OK;
} else if (!CONSP(entry)) {
*out = entry;
return LLPS_BAD_NAME;
}
// list
LispVal *name = XCAR(entry);
if (!is_valid_variable_name(name)) {
*out = name;
return LLPS_BAD_NAME;
} else if (!NILP(Fgethash(used_names, name, Qnil))) {
*out = name;
return LLPS_REPEAT_NAME;
}
Fputhash(used_names, name, Qt);
if (list_length_eq(entry, 1)) {
*out = LIST(XCAR(entry), Qnil, Qnil);
return LLPS_OK;
} else if (list_length_eq(entry, 2)) {
*out = LIST(name, XCAR(XCDR(entry)), Qnil);
return LLPS_OK;
} else if (list_length_eq(entry, 3)) {
LispVal *pvar = XCAR(XCDR(XCDR(entry)));
if (!is_valid_variable_name(pvar)) {
*out = pvar;
return LLPS_BAD_NAME;
} else if (!NILP(Fgethash(used_names, pvar, Qnil))) {
*out = pvar;
return LLPS_REPEAT_NAME;
}
Fputhash(used_names, pvar, Qt);
*out = LIST(XCAR(entry), XCAR(XCDR(entry)), pvar);
return LLPS_OK;
} else {
*out = entry;
return LLPS_INVALID_OPT_SPEC;
}
}
#define RETURN_ERROR(err, obj) \
{ \
release_hash_table_no_gc(used_names); \
result->status = err; \
result->err_obj = (obj); \
return; \
}
void parse_lambda_list(LambdaListParseResult *result, LispVal *list) {
enum { REQ = 0, OPT = 1, KEY = 2, REST = 4, MUST_CHANGE } mode = REQ;
unsigned int seen = 0;
result->err_obj = Qnil;
result->status = LLPS_OK;
struct LambdaList *out = &result->lambda_list;
LispVal *used_names = make_hash_table_no_gc(Qnil, Qnil);
// TODO check for repeat names
out->n_req = 0;
out->n_opt = 0;
out->allow_other_keys = false;
out->req = Qnil;
out->opt = Qnil;
out->kw = Qnil;
out->rest = Qnil;
size_t cur_idx = 0; // for keyword args
DOTAILS(tail, list) {
if (!LISTP(tail)) {
RETURN_ERROR(LLPS_DOTTED, list);
} else if (out->allow_other_keys) {
RETURN_ERROR(LLPS_AFTER_ALLOW_OTHER_KEYS, XCAR(tail));
}
LispVal *cur = XCAR(tail);
if (cur == Qand_allow_other_keys) {
if (out->allow_other_keys) {
RETURN_ERROR(LLPS_REPEAT_SECTION, cur);
} else if (!(seen & KEY)) {
RETURN_ERROR(LLPS_ORDER, cur);
}
out->allow_other_keys = true;
} else if (cur == Qand_rest) {
if (seen & REST) {
RETURN_ERROR(LLPS_REPEAT_SECTION, cur)
} else if (seen & KEY) {
RETURN_ERROR(LLPS_ORDER, cur);
}
seen |= REST;
mode = REST;
} else if (cur == Qand_optional) {
if (seen & OPT) {
RETURN_ERROR(LLPS_REPEAT_SECTION, cur)
} else if (seen & KEY || seen & REST) {
RETURN_ERROR(LLPS_ORDER, cur);
}
seen |= OPT;
mode = OPT;
} else if (cur == Qand_key) {
if (seen & KEY) {
RETURN_ERROR(LLPS_REPEAT_SECTION, list)
}
seen |= KEY;
mode = KEY;
out->kw = Fmake_hash_table(Qnil, Qnil);
} else if (mode == REST) {
if (!NILP(out->rest)) {
RETURN_ERROR(LLPS_REPEAT_REST, cur);
} else if (!is_valid_variable_name(cur)) {
RETURN_ERROR(LLPS_BAD_NAME, cur)
} else if (!NILP(Fgethash(used_names, cur, Qnil))) {
RETURN_ERROR(LLPS_REPEAT_NAME, cur);
}
Fputhash(used_names, cur, Qt);
out->rest = cur;
++cur_idx;
} else if (mode == OPT || mode == KEY) {
LispVal *entry;
LambdaListParseStatus status =
parse_optional_arg_spec(used_names, &entry, cur);
if (status != LLPS_OK) {
RETURN_ERROR(status, entry)
}
if (mode == OPT) {
out->opt = CONS(entry, out->opt);
++out->n_opt;
} else {
Fputhash(out->kw, intern_as_keyword(XCAR(entry)),
CONS(MAKE_FIXNUM(cur_idx), entry));
}
++cur_idx;
} else if (!is_valid_variable_name(cur)) {
RETURN_ERROR(LLPS_BAD_NAME, cur);
} else if (!NILP(Fgethash(used_names, cur, Qnil))) {
RETURN_ERROR(LLPS_REPEAT_NAME, cur);
} else {
Fputhash(used_names, cur, Qt);
out->req = CONS(cur, out->req);
++out->n_req;
++cur_idx;
}
}
out->req = Fnreverse(out->req);
out->opt = Fnreverse(out->opt);
release_hash_table_no_gc(used_names);
}
#undef RETURN_ERROR
LispVal *make_builtin_function(LispVal *name, LispVal *(*cfunc)(void),
const char *lisp_args, size_t args_len,
LispVal *docstr) {
LispFunction *obj = lisp_alloc_object(sizeof(LispFunction), TYPE_FUNCTION);
obj->name = name;
obj->type = FUNCTION_NATIVE;
obj->docstr = docstr;
obj->impl.native.no_eval_args = false;
obj->impl.native.addr.zero = cfunc;
ReadStream stream;
read_stream_init(&stream, lisp_args, args_len);
LispVal *args_form = read(&stream);
if (!args_form) {
fprintf(stderr, "Builtin function lambda list had a syntax error\n");
fprintf(stderr, "Name: ");
debug_print(stderr, name);
fprintf(stderr, "\nLambda list: \"%s\"\n", lisp_args);
exit(1);
}
LambdaListParseResult result;
parse_lambda_list(&result, args_form);
if (result.status != LLPS_OK) {
fprintf(stderr, "Error parsing builtin lambda list: %s\n",
llps_strerror(result.status));
fprintf(stderr, "Name: ");
debug_print(stderr, name);
fprintf(stderr, "\nLambda list: \"%s\"\n", lisp_args);
exit(1);
}
obj->args = result.lambda_list;
return obj;
}
// Calling functions
static ALWAYS_INLINE LispVal *evaluate_function_arguments(LispVal *args) {
LispVal *start = Qnil;
LispVal *end;
DOLIST(arg, args) {
if (NILP(start)) {
start = CONS(Feval(arg, Vlexical_environment), Qnil);
end = start;
} else {
RPLACD(end, CONS(Feval(arg, Vlexical_environment), Qnil));
end = XCDR(end);
}
}
return start;
}
enum ProcessArgsResult {
PROCESS_ARGS_OK,
PROCESS_ARGS_TOO_FEW,
PROCESS_ARGS_TOO_MANY,
PROCESS_ARGS_NO_KEY_VALUE,
PROCESS_ARGS_BAD_KEY,
PROCESS_ARGS_N_ERRORS,
};
static const char *process_args_strerror(enum ProcessArgsResult status) {
static const char *MSGS[PROCESS_ARGS_N_ERRORS] = {
[PROCESS_ARGS_OK] = "No error",
[PROCESS_ARGS_TOO_FEW] = "Not enough arguments",
[PROCESS_ARGS_TOO_MANY] = "Too many arguments",
[PROCESS_ARGS_NO_KEY_VALUE] = "Key without a value",
[PROCESS_ARGS_BAD_KEY] = "Unknown key",
};
return MSGS[status];
}
static ALWAYS_INLINE size_t NATIVE_FUNCTION_TOTAL_ARG_COUNT(LispVal *val) {
assert(FUNCTIONP(val));
LispFunction *fobj = val;
return fobj->args.n_req + fobj->args.n_opt + !NILP(fobj->args.rest)
+ (NILP(fobj->args.kw) ? 0 : HASH_TABLE_COUNT(fobj->args.kw));
}
static ALWAYS_INLINE enum ProcessArgsResult
process_complex_native_args(LispFunction *fobj, LispVal *args,
LispVal *restrict out[MAX_NATIVE_FUNCTION_ARGS],
intptr_t *rest_idx) {
size_t rem_req = fobj->args.n_req;
size_t rem_opt = fobj->args.n_opt;
size_t idx = 0;
while (rem_req--) {
if (NILP(args)) {
return PROCESS_ARGS_TOO_FEW;
}
out[idx++] = XCAR(args);
args = XCDR(args);
}
while (rem_opt--) {
if (NILP(args)) {
return PROCESS_ARGS_OK;
}
out[idx++] = XCAR(args);
args = XCDR(args);
}
if (!NILP(args) && (NILP(fobj->args.kw)) && NILP(fobj->args.rest)) {
return PROCESS_ARGS_TOO_MANY;
}
if (!NILP(fobj->args.rest)) {
*rest_idx = idx;
out[idx++] = args;
} else {
*rest_idx = -1;
}
if (NILP(fobj->args.kw)) { // we are not a keyword function
return PROCESS_ARGS_OK;
}
while (!NILP(args)) {
if (NILP(XCDR(args))) {
return PROCESS_ARGS_NO_KEY_VALUE;
}
LispVal *entry = Fgethash(fobj->args.kw, XCAR(args), Qnil);
if (!NILP(entry)) {
fixnum_t idx = XFIXNUM(XCAR(entry));
if (!out[idx]) {
out[idx] = XCAR(XCDR(args));
}
} else if (!fobj->args.allow_other_keys) {
return PROCESS_ARGS_BAD_KEY;
}
args = XCDR(XCDR(args));
}
return PROCESS_ARGS_OK;
}
static ALWAYS_INLINE LispVal *call_native(LispVal *orig_func,
LispFunction *fobj, LispVal *args) {
StackFrame *stack_ref = LISP_STACK_REF();
push_call_frame(orig_func, fobj, args);
if (!fobj->impl.native.no_eval_args) {
args = evaluate_function_arguments(args);
}
set_stack_evaluated_args(LISP_STACK_REF(), args);
LispVal *arg_arr[MAX_NATIVE_FUNCTION_ARGS] = {NULL};
size_t count = NATIVE_FUNCTION_TOTAL_ARG_COUNT(fobj);
intptr_t rest_idx;
enum ProcessArgsResult res =
process_complex_native_args(fobj, args, arg_arr, &rest_idx);
if (res != PROCESS_ARGS_OK) {
// TODO better errors
printf("Bad arguments to builtin \"");
debug_print(stdout, orig_func);
printf("\": %s\n", process_args_strerror(res));
abort();
}
for (intptr_t i = 0; i < count; ++i) {
if (!arg_arr[i]) {
arg_arr[i] = Qnil;
}
add_local_reference(LISP_STACK_REF(), arg_arr[i]);
}
LispVal *retval;
switch (count) {
case 0:
retval = fobj->impl.native.addr.zero();
break;
case 1:
retval = fobj->impl.native.addr.one(arg_arr[0]);
break;
case 2:
retval = fobj->impl.native.addr.two(arg_arr[0], arg_arr[1]);
break;
case 3:
retval =
fobj->impl.native.addr.three(arg_arr[0], arg_arr[1], arg_arr[2]);
break;
case 4:
retval = fobj->impl.native.addr.four(arg_arr[0], arg_arr[1], arg_arr[2],
arg_arr[3]);
break;
case 5:
retval = fobj->impl.native.addr.five(arg_arr[0], arg_arr[1], arg_arr[2],
arg_arr[3], arg_arr[4]);
break;
default:
abort();
}
the_stack.nogc_retval = retval;
unwind_to(stack_ref);
add_local_reference(LISP_STACK_REF(), the_stack.nogc_retval);
return retval;
}
static ALWAYS_INLINE void push_optional_argument_to_lexenv(LispVal *spec,
LispVal *value) {
new_lexical_variable(XCAR(spec), value);
if (!NILP(THIRD(spec))) {
new_lexical_variable(THIRD(spec), Qt);
}
}
static ALWAYS_INLINE void
push_missing_optional_argument_to_lexenv(LispVal *spec) {
new_lexical_variable(XCAR(spec), Feval(SECOND(spec), Vlexical_environment));
if (!NILP(THIRD(spec))) {
new_lexical_variable(THIRD(spec), Qnil);
}
}
static ALWAYS_INLINE enum ProcessArgsResult
push_interpreted_args_to_lexenv(LispFunction *fobj, LispVal *args) {
LispVal *rem_req = fobj->args.req;
LispVal *rem_opt = fobj->args.opt;
while (!NILP(rem_req)) {
if (NILP(args)) {
return PROCESS_ARGS_TOO_FEW;
}
new_lexical_variable(XCAR(rem_req), XCAR(args));
args = XCDR(args);
rem_req = XCDR(rem_req);
}
while (!NILP(rem_opt) && !NILP(args)) {
push_optional_argument_to_lexenv(XCAR(rem_opt), XCAR(args));
args = XCDR(args);
rem_opt = XCDR(rem_opt);
}
while (!NILP(rem_opt)) {
push_missing_optional_argument_to_lexenv(XCAR(rem_opt));
rem_opt = XCDR(rem_opt);
}
if (!NILP(fobj->args.rest)) {
new_lexical_variable(fobj->args.rest, args);
}
if (NILP(fobj->args.kw)) {
return !NILP(args) && NILP(fobj->args.rest) ? PROCESS_ARGS_TOO_MANY
: PROCESS_ARGS_OK;
}
LispVal *seen_kw = make_hash_table_no_gc(Qnil, Qnil);
while (!NILP(args)) {
if (NILP(XCDR(args))) {
release_hash_table_no_gc(seen_kw);
return PROCESS_ARGS_NO_KEY_VALUE;
}
// has index in front
LispVal *i_spec = Fgethash(fobj->args.kw, XCAR(args), Qnil);
if (!NILP(i_spec)) {
Fputhash(seen_kw, XCAR(args), Qt);
push_optional_argument_to_lexenv(XCDR(i_spec), SECOND(args));
} else if (!fobj->args.allow_other_keys) {
release_hash_table_no_gc(seen_kw);
return PROCESS_ARGS_BAD_KEY;
}
args = XCDR(XCDR(args));
}
HT_FOREACH_INDEX(fobj->args.kw, i) {
if (NILP(Fgethash(seen_kw, HASH_KEY(fobj->args.kw, i), Qnil))) {
push_missing_optional_argument_to_lexenv(
XCDR(HASH_VALUE(fobj->args.kw, i)));
}
}
release_hash_table_no_gc(seen_kw);
return PROCESS_ARGS_OK;
}
static ALWAYS_INLINE LispVal *
call_interpreted(LispVal *orig_func, LispFunction *fobj, LispVal *args) {
StackFrame *stack_ref = LISP_STACK_REF();
push_call_frame(orig_func, fobj, args);
LispVal *evaled_args = evaluate_function_arguments(args);
set_stack_evaluated_args(LISP_STACK_REF(), evaled_args);
push_dynamic_binding(Qlexical_environment, fobj->impl.interp.lexenv);
enum ProcessArgsResult par =
push_interpreted_args_to_lexenv(fobj, evaled_args);
if (par != PROCESS_ARGS_OK) {
// TODO better error handling
fprintf(stderr, "Bad args to interp func: %s\n",
process_args_strerror(par));
abort();
}
LispVal *rval = Fprogn(fobj->impl.interp.body);
the_stack.nogc_retval = rval;
unwind_to(stack_ref);
add_local_reference(LISP_STACK_REF(), rval);
return rval;
}
DEFUN(funcall, "funcall", (LispVal * func, LispVal *args), "(func &rest args)",
"") {
LispFunction *fobj = func;
if (SYMBOLP(func)) {
fobj = Fsymbol_function(func, Qt);
} else if (CONSP(func) && EQ(XCAR(func), Qlambda)) {
fobj = Feval(func, Vlexical_environment);
}
// include symbol here for the error message
CHECK_TYPE(fobj, TYPE_FUNCTION, TYPE_SYMBOL);
assert(FUNCTIONP(fobj));
switch (fobj->type) {
case FUNCTION_NATIVE:
return call_native(func, fobj, args);
case FUNCTION_INTERP:
return call_interpreted(func, fobj, args);
default:
abort();
}
}
static LispVal *parse_lambda_declare_form(LispFunction *fobj, LispVal *body) {
while (CONSP(body) && CONSP(XCAR(body)) && EQ(XCAR(XCAR(body)), Qdeclare)) {
LispVal *decls = XCDR(XCAR(body));
DOLIST(decl, decls) {
if (EQ(XCAR(decl), Qname)) {
CHECK_TYPE(SECOND(decl), TYPE_SYMBOL);
if (!list_length_eq(decl, 2)) {
// TODO better error
fprintf(stderr, "Invalid (declare (name ...)) form!\n");
abort();
}
fobj->name = SECOND(decl);
}
}
body = XCDR(body);
}
return body;
}
DEFSPECIAL(lambda, "lambda", (LispVal * args, LispVal *body),
"(args &rest body)", "") {
LambdaListParseResult llpr;
parse_lambda_list(&llpr, args);
if (llpr.status != LLPS_OK) {
// TODO better handling
fprintf(stderr,
"Lambda list parse error: %s: ", llps_strerror(llpr.status));
debug_print(stderr, args);
fputc('\n', stderr);
abort();
}
CHECK_LISTP(body);
LispFunction *fobj = lisp_alloc_object(sizeof(LispFunction), TYPE_FUNCTION);
fobj->name = Qnil;
fobj->args = llpr.lambda_list;
fobj->type = FUNCTION_INTERP;
if (STRINGP(XCAR(body))) {
fobj->docstr = XCAR(body);
if (CONSP(XCDR(body))) {
body = XCDR(body);
}
} else {
fobj->docstr = Qnil;
}
body = parse_lambda_declare_form(fobj, body);
fobj->impl.interp.body = body;
fobj->impl.interp.lexenv = Vlexical_environment;
return fobj;
}
DEFINE_SYMBOL(declare, "declare");
DEFINE_SYMBOL(name, "name");