which can be `NULL` signifying "unknown". A `prop_err` flag set is
passed by reference. It has `Efail` set when an error is found, and
`Eretry` when the type for some element is set via propagation. If
-any expression cannot be evaluated immediately, `Enoconst` is set.
+any expression cannot be evaluated a compile time, `Eruntime` is set.
If the expression can be copied, `Emaycopy` is set.
If it remains unchanged at `0`, then no more propagation is needed.
###### ast
- enum val_rules {Rnolabel = 1<<0, Rboolok = 1<<1, Rnoconstant = 1<<2};
- enum prop_err {Efail = 1<<0, Eretry = 1<<1, Enoconst = 1<<2,
+ enum val_rules {Rboolok = 1<<1, Rnoconstant = 1<<2};
+ enum prop_err {Efail = 1<<0, Eretry = 1<<1, Eruntime = 1<<2,
Emaycopy = 1<<3};
-###### format cases
- case 'r':
- if (rules & Rnolabel)
- fputs(" (labels not permitted)", stderr);
- break;
-
###### forward decls
static struct type *propagate_types(struct exec *prog, struct parse_context *c, enum prop_err *perr,
struct type *type, int rules);
{
if ((rules & Rboolok) && have == Tbool)
return 1; // NOTEST
- if ((rules & Rnolabel) && have == Tlabel)
- return 0; // NOTEST
if (!require || !have)
return 1;
struct text str;
mpq_t num;
unsigned char bool;
- void *label;
+ int label;
###### ast functions
static void _free_value(struct type *type, struct value *v)
val->bool = 0;
break;
case Vlabel:
- val->label = NULL;
- break;
+ val->label = 0; // NOTEST
+ break; // NOTEST
}
}
case Vnone: // NOTEST
break; // NOTEST
case Vlabel:
- vnew->label = vold->label;
- break;
+ vnew->label = vold->label; // NOTEST
+ break; // NOTEST
case Vbool:
vnew->bool = vold->bool;
break;
case Vnone: // NOTEST
fprintf(f, "*no-value*"); break; // NOTEST
case Vlabel: // NOTEST
- fprintf(f, "*label-%p*", v->label); break; // NOTEST
+ fprintf(f, "*label-%d*", v->label); break; // NOTEST
case Vstr:
fprintf(f, "%.*s", v->str.len, v->str.txt); break;
case Vbool:
return v;
}
-###### Grammar
-
+###### declare terminals
$TERM True False
+###### Grammar
+
$*val
Value -> True ${
$0 = new_val(Tbool, $1);
{
struct val *val = cast(val, prog);
if (!type_compat(type, val->vtype, rules))
- type_err(c, "error: expected %1%r found %2",
+ type_err(c, "error: expected %1 found %2",
prog, type, rules, val->vtype);
return val->vtype;
}
return rv;
}
+#### Labels
+
+Labels are a temporary concept until I implement enums. There are an
+anonymous enum which is declared by usage. Thet are only allowed in
+`use` statements and corresponding `case` entries. They appear as a
+period followed by an identifier. All identifiers that are "used" must
+have a "case".
+
+For now, we have a global list of labels, and don't check that all "use"
+match "case".
+
+###### exec type
+ Xlabel,
+
+###### ast
+ struct label {
+ struct exec;
+ struct text name;
+ int value;
+ };
+###### free exec cases
+ case Xlabel:
+ free(e);
+ break;
+###### print exec cases
+ case Xlabel: {
+ struct label *l = cast(label, e);
+ printf(".%.*s", l->name.len, l->name.txt);
+ break;
+ }
+
+###### ast
+ struct labels {
+ struct labels *next;
+ struct text name;
+ int value;
+ };
+###### parse context
+ struct labels *labels;
+ int next_label;
+###### ast functions
+ static int label_lookup(struct parse_context *c, struct text name)
+ {
+ struct labels *l, **lp = &c->labels;
+ while (*lp && text_cmp((*lp)->name, name) < 0)
+ lp = &(*lp)->next;
+ if (*lp && text_cmp((*lp)->name, name) == 0)
+ return (*lp)->value;
+ l = calloc(1, sizeof(*l));
+ l->next = *lp;
+ l->name = name;
+ if (c->next_label == 0)
+ c->next_label = 2;
+ l->value = c->next_label;
+ c->next_label += 1;
+ *lp = l;
+ return l->value;
+ }
+
+###### free context storage
+ while (context.labels) {
+ struct labels *l = context.labels;
+ context.labels = l->next;
+ free(l);
+ }
+
+###### declare terminals
+ $TERM .
+###### term grammar
+ | . IDENTIFIER ${ {
+ struct label *l = new_pos(label, $ID);
+ l->name = $ID.txt;
+ $0 = l;
+ } }$
+###### propagate exec cases
+ case Xlabel: {
+ struct label *l = cast(label, prog);
+ l->value = label_lookup(c, l->name);
+ if (!type_compat(type, Tlabel, rules))
+ type_err(c, "error: expected %1 found %2",
+ prog, type, rules, Tlabel);
+ return Tlabel;
+ }
+###### interp exec cases
+ case Xlabel : {
+ struct label *l = cast(label, e);
+ rv.label = l->value;
+ rvtype = Tlabel;
+ break;
+ }
+
+
### Variables
Variables are scoped named values. We store the names in a linked list
v->previous->scope == PendingScope)
/* all previous branches used name */
v->scope = PendingScope;
- else if (v->type == Tlabel)
- /* Labels remain pending even when not used */
- v->scope = PendingScope; // UNTESTED
else
v->scope = OutScope;
if (ct == CloseElse) {
v->scope = InScope;
/* fallthrough */
case CloseSequential:
- if (v->type == Tlabel)
- v->scope = PendingScope;
switch (v->scope) {
case InScope:
v->scope = OutScope;
for (v2 = v;
v2 && v2->scope == PendingScope;
v2 = v2->previous)
- if (v2->type == Tlabel)
- v2->scope = CondScope;
- else
- v2->scope = OutScope;
+ v2->scope = OutScope;
break;
case CondScope:
case OutScope: break;
if (init)
memcpy(ret, init, t->size);
else
- val_init(t, ret);
+ val_init(t, ret); // NOTEST
return ret;
}
*perr |= Eretry;
}
} else if (!type_compat(type, v->type, rules)) {
- type_err(c, "error: expected %1%r but variable '%v' is %2", prog,
+ type_err(c, "error: expected %1 but variable '%v' is %2", prog,
type, rules, v->type);
type_err(c, "info: this is where '%v' was set to %1", v->where_set,
v->type, rules, NULL);
}
if (!v->global || v->frame_pos < 0)
- *perr |= Enoconst;
+ *perr |= Eruntime;
if (!type)
return v->type;
return type;
break;
###### declare terminals
- $TERM struct .
+ $TERM struct
###### term grammar
return val->ref != NULL;
}
+ static struct type *reference_fieldref(struct type *t, struct parse_context *c,
+ struct fieldref *f, struct value **vp)
+ {
+ struct type *rt = t->reference.referent;
+
+ if (rt->fieldref) {
+ if (vp)
+ *vp = (*vp)->ref;
+ return rt->fieldref(rt, c, f, vp);
+ }
+ type_err(c, "error: field reference on %1 is not supported",
+ f->left, rt, 0, NULL);
+ return Tnone;
+ }
+
+
static struct type reference_prototype = {
.print_type = reference_print_type,
.cmp_eq = reference_cmp,
.test = reference_test,
.free = reference_free,
.compat = reference_compat,
+ .fieldref = reference_fieldref,
.size = sizeof(void*),
.align = sizeof(void*),
};
prog, NULL, 0, NULL);
return NULL;
}
- *perr |= Enoconst;
+ *perr |= Eruntime;
v->var->type->check_args(c, perr, v->var->type, args);
if (v->var->type->function.inline_result)
*perr |= Emaycopy;
struct type *t2;
propagate_types(b->left, c, perr, Tbool, 0);
- t = propagate_types(b2->left, c, perr, type, Rnolabel);
- t2 = propagate_types(b2->right, c, perr, type ?: t, Rnolabel);
+ t = propagate_types(b2->left, c, perr, type, 0);
+ t2 = propagate_types(b2->right, c, perr, type ?: t, 0);
return t ?: t2;
}
case Eql:
case NEql:
/* Both must match but not be labels, result is Tbool */
- t = propagate_types(b->left, c, perr, NULL, Rnolabel);
+ t = propagate_types(b->left, c, perr, NULL, 0);
if (t)
propagate_types(b->right, c, perr, t, 0);
else {
- t = propagate_types(b->right, c, perr, NULL, Rnolabel); // UNTESTED
+ t = propagate_types(b->right, c, perr, NULL, 0); // UNTESTED
if (t) // UNTESTED
t = propagate_types(b->left, c, perr, t, 0); // UNTESTED
}
if (!type)
type = t;
else if (t != type)
- type_err(c, "error: expected %1%r, found %2",
+ type_err(c, "error: expected %1, found %2",
e->left, type, rules, t);
}
}
else
b = cast(binode, b->right);
while (b) {
- propagate_types(b->left, c, perr, NULL, Rnolabel);
+ propagate_types(b->left, c, perr, NULL, 0);
b = cast(binode, b->right);
}
break;
been declared as a constant. The analysis phase ensures that the type
will be correct so the interpreter just needs to perform the
calculation. There is a form of assignment which declares a new
-variable as well as assigning a value. If a name is assigned before
-it is declared, and error will be raised as the name is created as
-`Tlabel` and it is illegal to assign to such names.
+variable as well as assigning a value. If a name is used before
+it is declared, it is assumed to be a global constant which are allowed to
+be declared at any time.
###### Binode types
Assign,
* result is Tnone
*/
t = propagate_types(b->left, c, perr, NULL,
- Rnolabel | (b->op == Assign ? Rnoconstant : 0));
+ (b->op == Assign ? Rnoconstant : 0));
if (!b->right)
return Tnone;
type_err(c, "info: variable '%v' was set as %1 here.",
cast(var, b->left)->var->where_set, t, rules, NULL);
} else {
- t = propagate_types(b->right, c, perr, NULL, Rnolabel);
+ t = propagate_types(b->right, c, perr, NULL, 0);
if (t)
propagate_types(b->left, c, perr, t,
(b->op == Assign ? Rnoconstant : 0));
$0 = b = new_pos(binode, $1);
b->op = Use;
b->right = $<2;
- if (b->right->type == Xvar) {
- struct var *v = cast(var, b->right);
- if (v->var->type == Tnone) {
- /* Convert this to a label */
- struct value *val;
-
- v->var->type = Tlabel;
- val = global_alloc(c, Tlabel, v->var, NULL);
- val->label = val;
- }
- }
}$
###### print binode cases
} while (perr & Eretry);
if (perr & Efail)
c->parse_error += 1;
- else if (!(perr & Enoconst)) {
+ else if (!(perr & Eruntime)) {
progress = some;
struct value res = interp_exec(
c, vb->right, &v->var->type);
while
mid := (lo + hi) / 2
if mid == target:
- use Found
+ use .Found
if mid < target:
lo = mid
else
hi = mid
if hi - lo < 1:
lo = mid
- use GiveUp
+ use .GiveUp
use True
do pass
- case Found:
+ case .Found:
print "Yay, I found", target
- case GiveUp:
+ case .GiveUp:
print "Closest I found was", lo
size::= 10
code / ocean / blobdiff