From: NeilBrown Date: Mon, 13 Dec 2021 22:34:25 +0000 (+1100) Subject: oceani: change labels to look like enum values, not variables. X-Git-Url: https://ocean-lang.org/code/?p=ocean;a=commitdiff_plain;h=90e73c9514fc2dfbf7a88e7ce050f9b08a5c600a oceani: change labels to look like enum values, not variables. A label now looks like ".foo". This makes it a completely separate namespace from variables. When we introduce enums, the values will also look like ".foo" an we know which enum is intended based on context. Each switch/while will potentially create a local enum type for the labels. Signed-off-by: NeilBrown --- diff --git a/csrc/oceani-tests.mdc b/csrc/oceani-tests.mdc index 655a2c9..2ac2f56 100644 --- a/csrc/oceani-tests.mdc +++ b/csrc/oceani-tests.mdc @@ -382,19 +382,19 @@ Here I break it into two parts, keeping the array code separate. 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 ###### output: sayhello,55,33,hello,True @@ -874,6 +874,7 @@ various places that `type_err()` are called. b = b + 1 if 3 * 4 and not True: print "Weird" + d:number = .fred ###### output: type_err1 .tmp.code:3:25: error: expected string found number @@ -883,6 +884,8 @@ various places that `type_err()` are called. .tmp.code:6:8: error: Cannot assign to a constant: b .tmp.code:5:8: info: name was defined as a constant here .tmp.code:8:11: error: Arithmetic returns number but Boolean expected + .tmp.code:9:20: error: expected number found label + .tmp.code:9:8: info: variable 'd' was set as number here. oceani: type error in program - not running. ###### test: type_err2 diff --git a/csrc/oceani.mdc b/csrc/oceani.mdc index 1e2bfde..e147baa 100644 --- a/csrc/oceani.mdc +++ b/csrc/oceani.mdc @@ -1092,7 +1092,7 @@ A separate function encoding these cases will simplify some code later. 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) @@ -1125,8 +1125,8 @@ A separate function encoding these cases will simplify some code later. val->bool = 0; break; case Vlabel: - val->label = NULL; - break; + val->label = 0; // NOTEST + break; // NOTEST } } @@ -1137,8 +1137,8 @@ A separate function encoding these cases will simplify some code later. 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; @@ -1176,7 +1176,7 @@ A separate function encoding these cases will simplify some code later. 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: @@ -1261,10 +1261,11 @@ executable. return v; } -###### Grammar - +###### declare terminals $TERM True False +###### Grammar + $*val Value -> True ${ $0 = new_val(Tbool, $1); @@ -1361,6 +1362,98 @@ executable. 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%r 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 @@ -1838,9 +1931,6 @@ all pending-scope variables become conditionally scoped. 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) { @@ -1871,8 +1961,6 @@ all pending-scope variables become conditionally scoped. v->scope = InScope; /* fallthrough */ case CloseSequential: - if (v->type == Tlabel) - v->scope = PendingScope; switch (v->scope) { case InScope: v->scope = OutScope; @@ -1886,10 +1974,7 @@ all pending-scope variables become conditionally scoped. 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; @@ -1976,7 +2061,7 @@ tell if it was set or not later. if (init) memcpy(ret, init, t->size); else - val_init(t, ret); + val_init(t, ret); // NOTEST return ret; } @@ -2784,7 +2869,7 @@ function will be needed. break; ###### declare terminals - $TERM struct . + $TERM struct ###### term grammar @@ -4617,9 +4702,9 @@ An assignment will assign a value to a variable, providing it hasn't 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, @@ -4767,17 +4852,6 @@ function which has a return type, and the "condition" code blocks in $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 @@ -5869,19 +5943,19 @@ things which will likely grow as the languages grows. 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