From 74029a48cbc1e62f84bb82d7f00ece954389ec65 Mon Sep 17 00:00:00 2001
From: Mart Lubbers <mart@martlubbers.net>
Date: Mon, 8 Feb 2021 08:39:42 +0100
Subject: [PATCH] add tuples

---
 ast.c    | 24 +++++++++++++++++++++++-
 ast.h    |  7 ++++++-
 parse.y  |  1 +
 todo.txt |  1 -
 4 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/ast.c b/ast.c
index 97bd1ad..95ef8fd 100644
--- a/ast.c
+++ b/ast.c
@@ -12,7 +12,8 @@ static const char *ast_type_str[] = {
 	[an_fundecl] = "fundecl", [an_ident] = "ident", [an_if] = "if",
 	[an_int] = "int", [an_nil] = "nil", [an_list] = "list",
 	[an_return] = "return", [an_stmt_expr] = "stmt_expr",
-	[an_unop] = "unop", [an_vardecl] = "vardecl", [an_while] = "while",
+	[an_tuple] = "tuple", [an_unop] = "unop", [an_vardecl] = "vardecl",
+	[an_while] = "while",
 };
 #endif
 static const char *binop_str[] = {
@@ -276,6 +277,16 @@ struct ast *ast_stmt_expr(struct ast *expr)
 	return res;
 }
 
+struct ast *ast_tuple(struct ast *left, struct ast *right)
+{
+	struct ast *res = ast_alloc();
+	res->type = an_tuple;
+	res->data.an_tuple.left = left;
+	res->data.an_tuple.right = right;
+	return res;
+}
+
+
 struct ast *ast_unop(enum unop op, struct ast *l)
 {
 	struct ast *res = ast_alloc();
@@ -437,6 +448,13 @@ void ast_print(struct ast *ast, int indent, FILE *out)
 		ast_print(ast->data.an_stmt_expr, indent, out);
 		safe_fprintf(out, ";\n");
 		break;
+	case an_tuple:
+		safe_fprintf(out, "(");
+		ast_print(ast->data.an_tuple.left, indent, out);
+		safe_fprintf(out, ", ");
+		ast_print(ast->data.an_tuple.right, indent, out);
+		safe_fprintf(out, ")");
+		break;
 	case an_unop:
 		safe_fprintf(out, "(%s", unop_str[ast->data.an_unop.op]);
 		ast_print(ast->data.an_unop.l, indent, out);
@@ -531,6 +549,10 @@ void ast_free(struct ast *ast)
 	case an_stmt_expr:
 		ast_free(ast->data.an_stmt_expr);
 		break;
+	case an_tuple:
+		ast_free(ast->data.an_tuple.left);
+		ast_free(ast->data.an_tuple.right);
+		break;
 	case an_unop:
 		ast_free(ast->data.an_unop.l);
 		break;
diff --git a/ast.h b/ast.h
index 13d3c58..12263a7 100644
--- a/ast.h
+++ b/ast.h
@@ -14,7 +14,7 @@ enum unop {negate,inverse};
 enum ast_type {
 	an_assign, an_binop, an_bool, an_char, an_cons, an_funcall, an_fundecl,
 	an_ident, an_if, an_int, an_list, an_nil, an_return, an_stmt_expr,
-	an_unop, an_vardecl, an_while
+	an_tuple, an_unop, an_vardecl, an_while
 };
 struct ast {
 	enum ast_type type;
@@ -66,6 +66,10 @@ struct ast {
 		//struct { } an_nil;
 		struct ast *an_return;
 		struct ast *an_stmt_expr;
+		struct {
+			struct ast *left;
+			struct ast *right;
+		} an_tuple;
 		struct {
 			enum unop op;
 			struct ast *l;
@@ -97,6 +101,7 @@ struct ast *ast_list(struct ast *llist);
 struct ast *ast_nil();
 struct ast *ast_return(struct ast *rtrn);
 struct ast *ast_stmt_expr(struct ast *expr);
+struct ast *ast_tuple(struct ast *left, struct ast *right);
 struct ast *ast_unop(enum unop op, struct ast *l);
 struct ast *ast_vardecl(struct ast *ident, struct ast *l);
 struct ast *ast_while(struct ast *pred, struct ast *body);
diff --git a/parse.y b/parse.y
index c79a1ec..4311833 100644
--- a/parse.y
+++ b/parse.y
@@ -114,6 +114,7 @@ expr
 	| expr POWER expr { $$ = ast_binop($1, power, $3); }
 	| MINUS expr { $$ = ast_unop(negate, $2); }
 	| INVERSE expr %prec TIMES { $$ = ast_unop(inverse, $2); }
+	| BOPEN expr COMMA expr BCLOSE { $$ = ast_tuple($2, $4); }
 	| BOPEN expr BCLOSE { $$ = $2; }
 	| IDENT BOPEN fargs BCLOSE { $$ = ast_funcall($1, ast_list($3)); }
 	| INTEGER
diff --git a/todo.txt b/todo.txt
index e4b1181..edf9d6f 100644
--- a/todo.txt
+++ b/todo.txt
@@ -1,3 +1,2 @@
 parser:
-- tuples
 - types
-- 
2.20.1