From 9e55cdb1ea5cd8318a1a0b7a9f64f09e8d8ad692 Mon Sep 17 00:00:00 2001
From: Leo Tenenbaum <pommicket@gmail.com>
Date: Thu, 31 Oct 2019 17:10:36 -0400
Subject: a.b as an lvalue

---
 eval.c   | 22 +++++++++++++++++++---
 main.c   |  1 -
 parse.c  |  2 +-
 test.toc | 28 +++++++++-------------------
 toc.c    |  8 ++++++++
 types.c  |  8 ++++----
 6 files changed, 41 insertions(+), 28 deletions(-)

diff --git a/eval.c b/eval.c
index ff92ea9..ed88c2c 100644
--- a/eval.c
+++ b/eval.c
@@ -682,7 +682,15 @@ static bool eval_set(Evaluator *ev, Expression *set, Value *to) {
 			/* set it to to */
 			eval_deref_set(ptr, to, type);
 		} break;
-		default: break;
+		case BINARY_DOT: {
+			Value struc;
+			if (!eval_expr(ev, set->binary.lhs, &struc))
+				return false;
+			eval_struct_find_offsets(type_inner(&set->binary.lhs->type));
+			void *ptr = (char *)struc.struc + set->binary.field->offset;
+			eval_deref_set(ptr, to, set->binary.field->type);
+		} break;
+		default: assert(0); break;
 		}
 		break;
 	case EXPR_TUPLE:
@@ -812,6 +820,8 @@ static bool eval_expr(Evaluator *ev, Expression *e, Value *v) {
 				}
 				if (o->type.kind == TYPE_ARR)
 					v->ptr = id->val.arr; /* point directly to data */
+				else if (o->type.kind == TYPE_STRUCT)
+					v->ptr = id->val.struc;
 				else
 					v->ptr = &id->val;
 			} break;
@@ -833,7 +843,14 @@ static bool eval_expr(Evaluator *ev, Expression *e, Value *v) {
 						return false;
 					v->ptr = ptr;
 				} break;
-				default: break;
+				case BINARY_DOT: {
+					Value struc;
+					if (!eval_expr(ev, o->binary.lhs, &struc))
+						return false;
+					eval_struct_find_offsets(type_inner(&o->binary.lhs->type));
+					v->ptr = (char *)struc.struc + o->binary.field->offset;
+				} break;
+				default: assert(0); break;
 				}
 				break;
 			default:
@@ -1163,7 +1180,6 @@ static bool eval_decl(Evaluator *ev, Declaration *d) {
 		while (inner_type->kind == TYPE_USER)
 			inner_type = ident_typeval(type->user.name);
 		if (inner_type->kind == TYPE_STRUCT) {
-			puts("Allocating space for struct");
 			id->val.struc = err_calloc(1, compiler_sizeof(inner_type));
 		} else if (inner_type->kind == TYPE_ARR) {
 			id->val.arr = err_calloc(inner_type->arr.n, compiler_sizeof(inner_type->arr.of));
diff --git a/main.c b/main.c
index 80e5371..ec7e164 100644
--- a/main.c
+++ b/main.c
@@ -1,6 +1,5 @@
 /* 
 TODO:
-. lvalue
 using dot with pointers
 length of slice/arr with .len
 verify size of struct, align of fields
diff --git a/parse.c b/parse.c
index 4e43eef..cb11412 100644
--- a/parse.c
+++ b/parse.c
@@ -957,7 +957,7 @@ static bool parse_expr(Parser *p, Expression *e, Token *end) {
 				if (token_is_kw(t->token, KW_LPAREN))
 					tokr_err(t, "Direct function calling in an expression is not supported.\nYou can wrap the function in parentheses.");
 				else
-					tokr_err(t, "Expected end of expression.");
+					tokr_err(t, "Expected end of function (did you forget a semicolon?).");
 				return false;
 			}
 			return true;
diff --git a/test.toc b/test.toc
index 4fdc819..3fc2dc2 100644
--- a/test.toc
+++ b/test.toc
@@ -4,28 +4,18 @@ puti @= fn(x: int) {
 };
 
 Point @= struct {
-	x_coordinate, y_coordinate : int;
-	f : fn();
+	x, y : int;
 };
 
-somefn @= fn() int {
-	 p:Point;
-	 x := p.({
-	   t @= int;
-	   f @= fn() t { 7 as t };
-	   if f() as int > 3 {
-	   	  "x_coordinate"
-	   } else {
-	   	 "y_coordinate"
-	   }
-	 });
-	 x
+sum34 @= fn() int {
+	 p: Point;
+	 x := &p.x;
+	 *x = 3;
+	 p.y = 4;
+	 p.x + p.y
 };
 
 main @= fn() {
-	 p: Point;
-	 X @= somefn();
-	 puti(X);
-	 puti(somefn());
-	 puti(p.x_coordinate);
+X @= sum34();
+puti(sum34());
 };
diff --git a/toc.c b/toc.c
index 62ffc0b..243baaa 100644
--- a/toc.c
+++ b/toc.c
@@ -22,6 +22,14 @@
 #include "tokenizer.c"
 #include "parse.c"
 #include "scope.c"
+
+
+static Type *type_inner(Type *t) {
+	while (t->kind == TYPE_USER)
+		t = ident_typeval(t->user.name);
+	return t;
+}
+
 #include "eval.c"
 #include "types.c"
 static bool cgen_decls_file(CGenerator *g, ParsedFile *f);
diff --git a/types.c b/types.c
index 8769907..0726550 100644
--- a/types.c
+++ b/types.c
@@ -171,17 +171,18 @@ static bool expr_must_lval(Expression *e) {
 	case EXPR_BINARY_OP:
 		switch (e->binary.op) {
 		case BINARY_AT_INDEX: return true;
+		case BINARY_DOT: return true;
 		default: break;
 		}
-		break;
-	case EXPR_TUPLE: {
+		err_print(e->where, "Cannot use operator %s as l-value", binary_op_to_str(e->binary.op));
+	    return false;
+	case EXPR_TUPLE:
 		/* x, y is an lval, but 3, "hello" is not. */
 		arr_foreach(e->tuple, Expression, x) {
 			if (!expr_must_lval(x)) 
 				return false;
 		}
 		return true;
-	} break;
 	case EXPR_CAST:
 	case EXPR_NEW:
 	case EXPR_FN:
@@ -1352,4 +1353,3 @@ static bool types_file(Typer *tr, ParsedFile *f) {
 static void typer_free(Typer *tr) {
 	allocr_free_all(&tr->allocr);
 }
-
-- 
cgit v1.2.3