From 9429d1ea0d14effbf50b6ecf292ef4d6a5a98abc Mon Sep 17 00:00:00 2001
From: Robert Konrad <git2016@robdangero.us>
Date: Fri, 16 Aug 2024 17:46:22 +0200
Subject: [PATCH] Support do while loops

---
 Sources/compiler.c | 35 +++++++++++++++++++++++++++++++++--
 Sources/kong.c     |  7 ++++---
 Sources/parser.c   | 28 ++++++++++++++++++++++++++--
 Sources/parser.h   | 12 ++++++++++--
 4 files changed, 73 insertions(+), 9 deletions(-)

diff --git a/Sources/compiler.c b/Sources/compiler.c
index bdf4c1b..b394001 100644
--- a/Sources/compiler.c
+++ b/Sources/compiler.c
@@ -562,14 +562,45 @@ void emit_statement(opcodes *code, block *parent, statement *statement) {
 			o.type = OPCODE_WHILE_CONDITION;
 			o.size = OP_SIZE(o, op_while);
 
-			variable v = emit_expression(code, parent, statement->willy.test);
+			variable v = emit_expression(code, parent, statement->whiley.test);
 
 			o.op_while.condition = v;
 
 			emit_op(code, &o);
 		}
 
-		emit_statement(code, parent, statement->willy.while_block);
+		emit_statement(code, parent, statement->whiley.while_block);
+
+		{
+			opcode o;
+			o.type = OPCODE_WHILE_END;
+			o.size = OP_SIZE(o, op_nothing);
+			emit_op(code, &o);
+		}
+
+		break;
+	}
+	case STATEMENT_DO_WHILE: {
+		{
+			opcode o;
+			o.type = OPCODE_WHILE_START;
+			o.size = OP_SIZE(o, op_nothing);
+			emit_op(code, &o);
+		}
+
+		emit_statement(code, parent, statement->whiley.while_block);
+
+		{
+			opcode o;
+			o.type = OPCODE_WHILE_CONDITION;
+			o.size = OP_SIZE(o, op_while);
+
+			variable v = emit_expression(code, parent, statement->whiley.test);
+
+			o.op_while.condition = v;
+
+			emit_op(code, &o);
+		}
 
 		{
 			opcode o;
diff --git a/Sources/kong.c b/Sources/kong.c
index d8749e4..ebbc76e 100644
--- a/Sources/kong.c
+++ b/Sources/kong.c
@@ -277,9 +277,10 @@ void resolve_types_in_block(statement *parent, statement *block) {
 			}
 			break;
 		}
-		case STATEMENT_WHILE: {
-			resolve_types_in_expression(block, s->willy.test);
-			resolve_types_in_block(block, s->willy.while_block);
+		case STATEMENT_WHILE:
+		case STATEMENT_DO_WHILE: {
+			resolve_types_in_expression(block, s->whiley.test);
+			resolve_types_in_block(block, s->whiley.while_block);
 			break;
 		}
 		case STATEMENT_BLOCK: {
diff --git a/Sources/parser.c b/Sources/parser.c
index d2c7a8c..2a2f91e 100644
--- a/Sources/parser.c
+++ b/Sources/parser.c
@@ -330,8 +330,32 @@ static statement *parse_statement(state_t *state, block *parent_block) {
 		statement *while_block = parse_statement(state, parent_block);
 		statement *s = statement_allocate();
 		s->kind = STATEMENT_WHILE;
-		s->willy.test = test;
-		s->willy.while_block = while_block;
+		s->whiley.test = test;
+		s->whiley.while_block = while_block;
+
+		return s;
+	}
+	case TOKEN_DO: {
+		advance_state(state);
+		
+		statement *do_block = parse_statement(state, parent_block);
+		statement *s = statement_allocate();
+		s->kind = STATEMENT_DO_WHILE;
+		s->whiley.while_block = do_block;
+
+		match_token(state, TOKEN_WHILE, "Expected \"while\"");
+		advance_state(state);
+		match_token(state, TOKEN_LEFT_PAREN, "Expected an opening bracket");
+		advance_state(state);
+
+		expression *test = parse_expression(state);
+		match_token(state, TOKEN_RIGHT_PAREN, "Expected a closing bracket");
+		advance_state(state);
+
+		s->whiley.test = test;
+
+		match_token(state, TOKEN_SEMICOLON, "Expected a semicolon");
+		advance_state(state);
 
 		return s;
 	}
diff --git a/Sources/parser.h b/Sources/parser.h
index cc9719f..6e1fc2e 100644
--- a/Sources/parser.h
+++ b/Sources/parser.h
@@ -88,7 +88,15 @@ typedef struct block {
 } block;
 
 typedef struct statement {
-	enum { STATEMENT_EXPRESSION, STATEMENT_RETURN_EXPRESSION, STATEMENT_IF, STATEMENT_WHILE, STATEMENT_BLOCK, STATEMENT_LOCAL_VARIABLE } kind;
+	enum {
+		STATEMENT_EXPRESSION,
+		STATEMENT_RETURN_EXPRESSION,
+		STATEMENT_IF,
+		STATEMENT_WHILE,
+		STATEMENT_DO_WHILE,
+		STATEMENT_BLOCK,
+		STATEMENT_LOCAL_VARIABLE
+	} kind;
 
 	union {
 		expression *expression;
@@ -100,7 +108,7 @@ typedef struct statement {
 		struct {
 			expression *test;
 			struct statement *while_block;
-		} willy;
+		} whiley;
 		block block;
 		struct {
 			local_variable var;