feat: Add support to subscript assignments

compiler/src/ast.c

@@ -39,11 +39,11 @@ struct statement* declaration_statement_new(struct statement* assignment) {
 }
 
 
-struct statement* assignment_statement_new(char* id, struct expression* expr) {
+struct statement* assignment_statement_new(struct expression* variable, struct expression* expr) {
 	_new(stat, statement);
 	stat->kind = ASSIGNMENT_STATEMENT;
 	stat->assignment = (struct assignment_statement) {
-		.id = id,
+		.variable = variable,
 		.value = expr,
 	};
 	return stat;

compiler/src/ast.h

@@ -102,7 +102,7 @@ struct expression {
 };
 
 struct assignment_statement {
-    char* id;
+    struct expression* variable;
     struct expression* value;
 };
 
@@ -140,7 +140,7 @@ struct block* block_new(void);
 void block_add_statement(struct block*, struct statement*);
 
 struct statement* declaration_statement_new(struct statement*);
-struct statement* assignment_statement_new(char*, struct expression*);
+struct statement* assignment_statement_new(struct expression*, struct expression*);
 struct statement* expr_statement_new(struct expression*);
 struct statement* if_statement_new(struct expression*, struct block*, struct block*);
 struct statement* while_statement_new(struct expression*, struct block*);

compiler/src/codegen_stat.c

@@ -12,19 +12,25 @@
 
 
 static void codegen_assignment_statement(FILE* out, scope_t* scope, struct assignment_statement statement) {
-    region_t* region = codegen_expr(out, scope, statement.value);
-    region_t* var = scope_get(scope, statement.id);
-    if (!var) {
-        fprintf(stderr, "variable not found: %s\n", statement.id);
-        panic("unknown variable");
+    region_t* value = codegen_expr(out, scope, statement.value);
+    region_t* var = codegen_expr(out, scope, statement.variable);
+
+    if (statement.variable->kind != VARIABLE) {
+        fprintf(stderr, "assigment lhs is not a variable (%d)\n", statement.variable->kind);
+        panic("not a variable");
     }
 
-    if (var->start != region->start) {
+    if (var->start != value->start) {
         reset_region(var);
-        copy(region, var);
+        copy(value, var);
     }
 
-    region_used(region);
+    region_used(value);
+
+    if (statement.variable->variable.is_offset) {
+        // lhs is offset -> free ref
+        scope_remove(scope, var);
+    }
 }
 
 // only used by decl_statement
@@ -61,8 +67,13 @@ static region_t* clone_region(FILE* out, scope_t* scope, region_t* original) {
 }
 
 static void codegen_decl_statement(FILE* out, scope_t* scope, struct assignment_statement statement) {
-    if (scope_get(scope, statement.id)) {
-        fprintf(stderr, "variable exists: %s\n", statement.id);
+    if (statement.variable->kind != VARIABLE || statement.variable->variable.is_offset) {
+        fprintf(stderr, "decl lhs is not a variable (%d)\n", statement.variable->kind);
+        panic("not a variable");
+    }
+
+    if (scope_get(scope, statement.variable->variable.id)) {
+        fprintf(stderr, "variable exists: %s\n", statement.variable->variable.id);
         panic("variable exists");
     }
 
@@ -72,7 +83,7 @@ static void codegen_decl_statement(FILE* out, scope_t* scope, struct assignment_
         region = clone_region(out, scope, region);
     }
 
-    scope_existing(scope, region, statement.id);
+    scope_existing(scope, region, statement.variable->variable.id);
 }
 
 static void codegen_if_statement(FILE* out, scope_t* scope, struct if_statement statement) {

compiler/src/parser.y

@@ -107,7 +107,7 @@ definition: VAR assignment
 		}
 ;
 
-assignment: ID ASSIGNMENT expr
+assignment: variable ASSIGNMENT expr
 		{
 			$$ = assignment_statement_new($1, $3);
 		}

compiler/test/cases/020e-assignment-to-arrray-subscript.in

@@ -0,0 +1,4 @@
+var a = []{'f', 'o', 'o', '\n'};
+a[2] = 'O';
+
+print(a);

compiler/test/cases/020e-assignment-to-arrray-subscript.out

@@ -0,0 +1,3 @@
+>>>>[-]++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]<[-<<<<+>>>>>+<]>[-<+>]<[-]+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]<[-<<<+>>>>+<]>[-<+>]<[-]+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]<[-<<+>>>+<]>[-<+>]<[-]++++++++++>[-]<[-<+>>+<]>[-<+>]
+<[-]+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++<<[-]>>>[-]<[-<<+>>>+<]>[-<+>]
+<<<<<.>.>.>.

compiler/test/cases/020g-assignment-to-str-subscript.in

@@ -0,0 +1,4 @@
+var foo = "Hello, vorld!\n";
+foo[7] = 'W';
+
+print(foo);

compiler/test/cases/020g-assignment-to-str-subscript.out

@@ -0,0 +1,3 @@
+[-]++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]++++++++++++++++++++++++++++++++++++++++++++>[-]++++++++++++++++++++++++++++++++>[-]++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]+++++++++++++++++++++++++++++++++>[-]++++++++++
+>[-]+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++<<<<<<<[-]>>>>>>>>[-]<[-<<<<<<<+>>>>>>>>+<]>[-<+>]
+<<<<<<<<<<<<<<<.>.>.>.>.>.>.>.>.>.>.>.>.>.