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-rw-r--r--src/library.c4
-rw-r--r--src/runtime.c106
-rw-r--r--src/runtime.h30
3 files changed, 96 insertions, 44 deletions
diff --git a/src/library.c b/src/library.c
index e30de4b..fed601e 100644
--- a/src/library.c
+++ b/src/library.c
@@ -27,7 +27,7 @@ static pit_value impl_sf_progn(pit_runtime *rt, pit_value args) {
}
pit_runtime_eval_program_push(rt, rt->program, (pit_runtime_eval_program_entry) {
.sort = EVAL_PROGRAM_ENTRY_LITERAL,
- .bind = final,
+ .literal = final,
});
return PIT_NIL;
}
@@ -37,7 +37,7 @@ static pit_value impl_sf_lambda(pit_runtime *rt, pit_value args) {
pit_value body = pit_cdr(rt, args);
pit_runtime_eval_program_push(rt, rt->program, (pit_runtime_eval_program_entry) {
.sort = EVAL_PROGRAM_ENTRY_LITERAL,
- .bind = pit_lambda(rt, as, body),
+ .literal = pit_lambda(rt, as, body),
});
return PIT_NIL;
}
diff --git a/src/runtime.c b/src/runtime.c
index d8d3a31..230b595 100644
--- a/src/runtime.c
+++ b/src/runtime.c
@@ -75,6 +75,8 @@ pit_runtime *pit_runtime_new() {
ret->saved_bindings = pit_values_new(1024);
ret->error = PIT_NIL;
pit_intern_cstr(ret, "nil"); // nil must be the 0th symbol for PIT_NIL to work
+ pit_value truth = pit_intern_cstr(ret, "t");
+ pit_set(ret, truth, truth);
pit_install_library_essential(ret);
return ret;
}
@@ -107,7 +109,15 @@ i64 pit_dump(pit_runtime *rt, char *buf, i64 len, pit_value v) {
if (!h) snprintf(buf, len, "<ref %d>", r);
else {
switch (h->hsort) {
- case PIT_VALUE_HEAVY_SORT_CONS:
+ case PIT_VALUE_HEAVY_SORT_CELL: {
+ char *end = buf + len;
+ char *start = buf;
+ *(buf++) = '{';
+ buf += pit_dump(rt, buf, end - buf, pit_car(rt, h->cell));
+ *(buf++) = '}';
+ return buf - start;
+ }
+ case PIT_VALUE_HEAVY_SORT_CONS: {
char *end = buf + len;
char *start = buf;
pit_value cur = v;
@@ -126,6 +136,7 @@ i64 pit_dump(pit_runtime *rt, char *buf, i64 len, pit_value v) {
*start = '(';
*(buf++) = ')';
return buf - start;
+ }
case PIT_VALUE_HEAVY_SORT_BYTES:
buf[0] = '"';
i64 i = 1;
@@ -261,6 +272,9 @@ bool pit_is_value_heavy_sort(pit_runtime *rt, pit_value a, enum pit_value_heavy_
}
return false;
}
+bool pit_is_cell(pit_runtime *rt, pit_value a) {
+ return pit_is_value_heavy_sort(rt, a, PIT_VALUE_HEAVY_SORT_CELL);
+}
bool pit_is_cons(pit_runtime *rt, pit_value a) {
return pit_is_value_heavy_sort(rt, a, PIT_VALUE_HEAVY_SORT_CONS);
}
@@ -293,6 +307,8 @@ bool pit_equal(pit_runtime *rt, pit_value a, pit_value b) {
if (!hb) { pit_error(rt, "bad ref"); return false; }
if (ha->hsort != hb->hsort) return false;
switch (ha->hsort) {
+ case PIT_VALUE_HEAVY_SORT_CELL:
+ return pit_equal(rt, ha->cell, hb->cell);
case PIT_VALUE_HEAVY_SORT_CONS:
return pit_equal(rt, ha->cons.car, hb->cons.car) && pit_equal(rt, ha->cons.cdr, hb->cons.cdr);
case PIT_VALUE_HEAVY_SORT_ARRAY:
@@ -386,25 +402,37 @@ bool pit_symbol_name_match(pit_runtime *rt, pit_value sym, u8 *buf, i64 len) {
bool pit_symbol_name_match_cstr(pit_runtime *rt, pit_value sym, char *s) {
return pit_symbol_name_match(rt, sym, (u8 *) s, strlen(s));
}
-pit_value pit_get(pit_runtime *rt, pit_value sym) {
+pit_value pit_get_value_cell(pit_runtime *rt, pit_value sym) {
pit_symtab_entry *ent = pit_symtab_lookup(rt, sym);
if (!ent) { pit_error(rt, "bad symbol"); return PIT_NIL; }
return ent->value;
}
+pit_value pit_get_function_cell(pit_runtime *rt, pit_value sym) {
+ pit_symtab_entry *ent = pit_symtab_lookup(rt, sym);
+ if (!ent) { pit_error(rt, "bad symbol"); return PIT_NIL; }
+ return ent->function;
+}
+pit_value pit_get(pit_runtime *rt, pit_value sym) {
+ return pit_cell_get(rt, pit_get_value_cell(rt, sym));
+}
void pit_set(pit_runtime *rt, pit_value sym, pit_value v) {
pit_symtab_entry *ent = pit_symtab_lookup(rt, sym);
if (!ent) { pit_error(rt, "bad symbol"); return; }
- ent->value = v;
+ if (pit_value_sort(ent->value) != PIT_VALUE_SORT_REF) {
+ ent->value = pit_cell_new(rt, PIT_NIL);
+ }
+ pit_cell_set(rt, ent->value, v);
}
pit_value pit_fget(pit_runtime *rt, pit_value sym) {
- pit_symtab_entry *ent = pit_symtab_lookup(rt, sym);
- if (!ent) { pit_error(rt, "bad symbol"); return PIT_NIL; }
- return ent->function;
+ return pit_cell_get(rt, pit_get_function_cell(rt, sym));
}
void pit_fset(pit_runtime *rt, pit_value sym, pit_value v) {
pit_symtab_entry *ent = pit_symtab_lookup(rt, sym);
if (!ent) { pit_error(rt, "bad symbol"); return; }
- ent->function = v;
+ if (pit_value_sort(ent->function) != PIT_VALUE_SORT_REF) {
+ ent->function = pit_cell_new(rt, PIT_NIL);
+ }
+ pit_cell_set(rt, ent->function, v);
}
bool pit_is_symbol_macro(pit_runtime *rt, pit_value sym) {
pit_symtab_entry *ent = pit_symtab_lookup(rt, sym);
@@ -434,11 +462,11 @@ void pit_sfset(pit_runtime *rt, pit_value sym, pit_value v) {
pit_fset(rt, sym, v);
pit_symbol_is_special_form(rt, sym);
}
-void pit_bind(pit_runtime *rt, pit_value sym, pit_value v) {
+void pit_bind(pit_runtime *rt, pit_value sym, pit_value cell) {
pit_symtab_entry *ent = pit_symtab_lookup(rt, sym);
if (!ent) { pit_error(rt, "bad symbol"); return; }
pit_values_push(rt, rt->saved_bindings, ent->value);
- ent->value = v;
+ ent->value = cell;
}
pit_value pit_unbind(pit_runtime *rt, pit_value sym) {
pit_symtab_entry *ent = pit_symtab_lookup(rt, sym);
@@ -448,6 +476,41 @@ pit_value pit_unbind(pit_runtime *rt, pit_value sym) {
return old;
}
+pit_value pit_cell_new(pit_runtime *rt, pit_value v) {
+ pit_value ret = pit_heavy_new(rt);
+ pit_value_heavy *h = pit_deref(rt, ret);
+ if (!h) { pit_error(rt, "failed to create new heavy value for cell"); return PIT_NIL; }
+ h->hsort = PIT_VALUE_HEAVY_SORT_CELL;
+ h->cell = v;
+ return ret;
+}
+pit_value pit_cell_get(pit_runtime *rt, pit_value cell) {
+ if (pit_value_sort(cell) != PIT_VALUE_SORT_REF) {
+ pit_error(rt, "cell value is not ref");
+ return PIT_NIL;
+ }
+ pit_value_heavy *h = pit_deref(rt, pit_as_ref(rt, cell));
+ if (!h) { pit_error(rt, "bad ref"); return PIT_NIL; }
+ if (h->hsort != PIT_VALUE_HEAVY_SORT_CELL) {
+ pit_error(rt, "cell value ref does not point to cell");
+ return PIT_NIL;
+ }
+ return h->cell;
+}
+void pit_cell_set(pit_runtime *rt, pit_value cell, pit_value v) {
+ if (pit_value_sort(cell) != PIT_VALUE_SORT_REF) {
+ pit_error(rt, "cell value is not ref");
+ return;
+ }
+ pit_value_heavy *h = pit_deref(rt, pit_as_ref(rt, cell));
+ if (!h) { pit_error(rt, "bad ref"); return; }
+ if (h->hsort != PIT_VALUE_HEAVY_SORT_CELL) {
+ pit_error(rt, "cell value ref does not point to cell");
+ return;
+ }
+ h->cell = v;
+}
+
pit_value pit_cons(pit_runtime *rt, pit_value car, pit_value cdr) {
pit_value ret = pit_heavy_new(rt);
pit_value_heavy *h = pit_deref(rt, ret);
@@ -527,14 +590,6 @@ pit_value pit_contains_eq(pit_runtime *rt, pit_value needle, pit_value haystack)
return PIT_NIL;
}
-static pit_value extract_let_binds(pit_runtime *rt, pit_value tail, pit_value binds) {
- pit_value ret = tail;
- while (binds != PIT_NIL) {
- ret = pit_cons(rt, pit_car(rt, pit_car(rt, binds)), ret);
- binds = pit_cdr(rt, binds);
- }
- return ret;
-}
pit_value pit_free_vars(pit_runtime *rt, pit_value args, pit_value body) {
i64 expr_stack_reset = rt->expr_stack->top;
pit_value bound = args;
@@ -577,8 +632,8 @@ pit_value pit_lambda(pit_runtime *rt, pit_value args, pit_value body) {
pit_value env = PIT_NIL;
while (freevars != PIT_NIL) {
pit_value sym = pit_car(rt, freevars);
- pit_value v = pit_get(rt, sym);
- env = pit_cons(rt, pit_cons(rt, sym, v), env);
+ pit_value cell = pit_get_value_cell(rt, sym);
+ env = pit_cons(rt, pit_cons(rt, sym, cell), env);
freevars = pit_cdr(rt, freevars);
}
h->hsort = PIT_VALUE_HEAVY_SORT_FUNC;
@@ -615,7 +670,8 @@ pit_value pit_apply(pit_runtime *rt, pit_value f, pit_value args) {
pit_value anames = h->func.args;
while (anames != PIT_NIL) {
pit_value nm = pit_car(rt, anames);
- pit_bind(rt, nm, pit_car(rt, args));
+ pit_value c = pit_cell_new(rt, pit_car(rt, args));
+ pit_bind(rt, nm, c);
bound = pit_cons(rt, nm, bound);
args = pit_cdr(rt, args);
anames = pit_cdr(rt, anames);
@@ -626,8 +682,7 @@ pit_value pit_apply(pit_runtime *rt, pit_value f, pit_value args) {
pit_value b = pit_car(rt, env);
pit_value nm = pit_car(rt, b);
pit_value v = pit_get(rt, nm);
- printf("updating closure\n");
- pit_setcdr(rt, b, v);
+ pit_cell_set(rt, pit_cdr(rt, b), v);
env = pit_cdr(rt, env);
}
pit_value ret = pit_eval(rt, h->func.body);
@@ -854,13 +909,6 @@ pit_value pit_eval(pit_runtime *rt, pit_value top) {
}
pit_values_push(rt, rt->result_stack, pit_apply(rt, f, args));
break;
- case EVAL_PROGRAM_ENTRY_BIND:
- pit_value v = pit_values_pop(rt, rt->result_stack);
- pit_bind(rt, ent->bind, v);
- break;
- case EVAL_PROGRAM_ENTRY_UNBIND:
- pit_unbind(rt, ent->unbind);
- break;
default:
pit_error(rt, "unknown program entry");
goto end;
diff --git a/src/runtime.h b/src/runtime.h
index 539c8a9..c5040f1 100644
--- a/src/runtime.h
+++ b/src/runtime.h
@@ -43,13 +43,15 @@ pit_value pit_values_pop(struct pit_runtime *rt, pit_values *s);
typedef pit_value (*pit_nativefunc)(struct pit_runtime *rt, pit_value args);
typedef struct { // "heavy" values, the targets of refs
enum pit_value_heavy_sort {
- PIT_VALUE_HEAVY_SORT_CONS=0,
- PIT_VALUE_HEAVY_SORT_ARRAY,
- PIT_VALUE_HEAVY_SORT_BYTES,
- PIT_VALUE_HEAVY_SORT_FUNC,
- PIT_VALUE_HEAVY_SORT_NATIVEFUNC,
+ PIT_VALUE_HEAVY_SORT_CELL=0, // "value cell" - basically, a "location" referred to by a variable binding
+ PIT_VALUE_HEAVY_SORT_CONS, // cons cell - a pair of two values
+ PIT_VALUE_HEAVY_SORT_ARRAY, // fixed-size array of values
+ PIT_VALUE_HEAVY_SORT_BYTES, // bytestring
+ PIT_VALUE_HEAVY_SORT_FUNC, // Lisp closure
+ PIT_VALUE_HEAVY_SORT_NATIVEFUNC, // native function
} hsort;
union {
+ pit_value cell;
struct { pit_value car, cdr; } cons;
struct { pit_value *data; i64 len; } array;
struct { u8 *data; i64 len; } bytes;
@@ -59,9 +61,9 @@ typedef struct { // "heavy" values, the targets of refs
} pit_value_heavy;
typedef struct {
- pit_value name;
- pit_value value;
- pit_value function;
+ pit_value name; // ref to bytestring
+ pit_value value; // ref to cell
+ pit_value function; // ref to cell
bool is_macro, is_special_form;
} pit_symtab_entry;
@@ -70,14 +72,10 @@ typedef struct {
enum {
EVAL_PROGRAM_ENTRY_LITERAL,
EVAL_PROGRAM_ENTRY_APPLY,
- EVAL_PROGRAM_ENTRY_BIND,
- EVAL_PROGRAM_ENTRY_UNBIND,
} sort;
union {
pit_value literal;
i64 apply; // arity of application
- pit_value bind; // symbol to bind
- pit_value unbind; // symbol to unbind
};
} pit_runtime_eval_program_entry;
typedef struct {
@@ -126,11 +124,12 @@ bool pit_is_integer(pit_runtime *rt, pit_value a);
bool pit_is_double(pit_runtime *rt, pit_value a);
bool pit_is_symbol(pit_runtime *rt, pit_value a);
bool pit_is_value_heavy_sort(pit_runtime *rt, pit_value a, enum pit_value_heavy_sort e);
+bool pit_is_cell(pit_runtime *rt, pit_value a);
bool pit_is_cons(pit_runtime *rt, pit_value a);
bool pit_is_array(pit_runtime *rt, pit_value a);
bool pit_is_bytes(pit_runtime *rt, pit_value a);
+bool pit_is_func(pit_runtime *rt, pit_value a);
bool pit_is_nativefunc(pit_runtime *rt, pit_value a);
-bool pit_truthful(pit_value a);
bool pit_eq(pit_value a, pit_value b);
bool pit_equal(pit_runtime *rt, pit_value a, pit_value b);
@@ -158,6 +157,11 @@ void pit_sfset(pit_runtime *rt, pit_value sym, pit_value v);
void pit_bind(pit_runtime *rt, pit_value sym, pit_value v);
pit_value pit_unbind(pit_runtime *rt, pit_value sym);
+// working with cells
+pit_value pit_cell_new(pit_runtime *rt, pit_value v);
+pit_value pit_cell_get(pit_runtime *rt, pit_value cell);
+void pit_cell_set(pit_runtime *rt, pit_value cell, pit_value v);
+
// working with cons cells
pit_value pit_cons(pit_runtime *rt, pit_value car, pit_value cdr);
pit_value pit_list(pit_runtime *rt, i64 num, ...);
generated by cgit v1.2.3 (git 2.25.1) at 2026-05-09 13:37:12 +0000