From cf0c081da0e1327f2fc2d28c764672da5133c8cd Mon Sep 17 00:00:00 2001
From: Robert Konrad <git2016@robdangero.us>
Date: Thu, 15 Aug 2024 20:31:09 +0200
Subject: [PATCH] Support limitless while loops

---
 Sources/backends/cstyle.c |  4 ++++
 Sources/compiler.c        | 17 +++++++++++++++++
 Sources/compiler.h        |  4 ++++
 Sources/kong.c            |  5 +++++
 Sources/parser.c          | 17 +++++++++++++++++
 Sources/parser.h          |  6 +++++-
 Sources/tokenizer.c       |  9 +++++++++
 Sources/tokenizer.h       |  3 +++
 8 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/Sources/backends/cstyle.c b/Sources/backends/cstyle.c
index bb5df25..9d45cea 100644
--- a/Sources/backends/cstyle.c
+++ b/Sources/backends/cstyle.c
@@ -165,6 +165,10 @@ void cstyle_write_opcode(char *code, size_t *offset, opcode *o, type_string_func
 		*offset += sprintf(&code[*offset], "\telse\n");
 		break;
 	}
+	case OPCODE_WHILE: {
+		*offset += sprintf(&code[*offset], "\twhile (_%" PRIu64 ")\n", o->op_if.condition.index);
+		break;
+	}
 	case OPCODE_BLOCK_START: {
 		*offset += sprintf(&code[*offset], "\t{\n");
 		break;
diff --git a/Sources/compiler.c b/Sources/compiler.c
index 2e235bf..c2cbbd3 100644
--- a/Sources/compiler.c
+++ b/Sources/compiler.c
@@ -549,6 +549,23 @@ void emit_statement(opcodes *code, block *parent, statement *statement) {
 
 		break;
 	}
+	case STATEMENT_WHILE: {
+		{
+			opcode o;
+			o.type = OPCODE_WHILE;
+			o.size = OP_SIZE(o, op_while);
+
+			variable v = emit_expression(code, parent, statement->willy.test);
+
+			o.op_while.condition = v;
+
+			emit_op(code, &o);
+		}
+
+		emit_statement(code, parent, statement->willy.while_block);
+
+		break;
+	}
 	case STATEMENT_BLOCK: {
 		{
 			opcode o;
diff --git a/Sources/compiler.h b/Sources/compiler.h
index 6c41041..df82dc0 100644
--- a/Sources/compiler.h
+++ b/Sources/compiler.h
@@ -42,6 +42,7 @@ typedef struct opcode {
 		OPCODE_OR,
 		OPCODE_IF,
 		OPCODE_ELSE,
+		OPCODE_WHILE,
 		OPCODE_BLOCK_START,
 		OPCODE_BLOCK_END
 	} type;
@@ -95,6 +96,9 @@ typedef struct opcode {
 		struct {
 			variable condition;
 		} op_if;
+		struct {
+			variable condition;
+		} op_while;
 		struct {
 			uint8_t nothing;
 		} op_nothing;
diff --git a/Sources/kong.c b/Sources/kong.c
index b67cec9..d8749e4 100644
--- a/Sources/kong.c
+++ b/Sources/kong.c
@@ -277,6 +277,11 @@ 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);
+			break;
+		}
 		case STATEMENT_BLOCK: {
 			resolve_types_in_block(block, s);
 			break;
diff --git a/Sources/parser.c b/Sources/parser.c
index ff65b57..d2c7a8c 100644
--- a/Sources/parser.c
+++ b/Sources/parser.c
@@ -318,6 +318,23 @@ static statement *parse_statement(state_t *state, block *parent_block) {
 
 		return s;
 	}
+	case TOKEN_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);
+
+		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;
+
+		return s;
+	}
 	case TOKEN_LEFT_CURLY: {
 		return parse_block(state, parent_block);
 	}
diff --git a/Sources/parser.h b/Sources/parser.h
index bf18415..cc9719f 100644
--- a/Sources/parser.h
+++ b/Sources/parser.h
@@ -88,7 +88,7 @@ typedef struct block {
 } block;
 
 typedef struct statement {
-	enum { STATEMENT_EXPRESSION, STATEMENT_RETURN_EXPRESSION, STATEMENT_IF, STATEMENT_BLOCK, STATEMENT_LOCAL_VARIABLE } kind;
+	enum { STATEMENT_EXPRESSION, STATEMENT_RETURN_EXPRESSION, STATEMENT_IF, STATEMENT_WHILE, STATEMENT_BLOCK, STATEMENT_LOCAL_VARIABLE } kind;
 
 	union {
 		expression *expression;
@@ -97,6 +97,10 @@ typedef struct statement {
 			struct statement *if_block;
 			struct statement *else_block;
 		} iffy;
+		struct {
+			expression *test;
+			struct statement *while_block;
+		} willy;
 		block block;
 		struct {
 			local_variable var;
diff --git a/Sources/tokenizer.c b/Sources/tokenizer.c
index 7148ea7..d76127a 100644
--- a/Sources/tokenizer.c
+++ b/Sources/tokenizer.c
@@ -164,6 +164,15 @@ static void tokens_add_identifier(tokenizer_state *state, tokens *tokens, tokeni
 	else if (tokenizer_buffer_equals(buffer, "else")) {
 		token = token_create(TOKEN_ELSE, state);
 	}
+	else if (tokenizer_buffer_equals(buffer, "while")) {
+		token = token_create(TOKEN_WHILE, state);
+	}
+	else if (tokenizer_buffer_equals(buffer, "do")) {
+		token = token_create(TOKEN_DO, state);
+	}
+	else if (tokenizer_buffer_equals(buffer, "for")) {
+		token = token_create(TOKEN_FOR, state);
+	}
 	else if (tokenizer_buffer_equals(buffer, "in")) {
 		token = token_create(TOKEN_IN, state);
 	}
diff --git a/Sources/tokenizer.h b/Sources/tokenizer.h
index 429da93..22f6715 100644
--- a/Sources/tokenizer.h
+++ b/Sources/tokenizer.h
@@ -45,6 +45,9 @@ typedef struct token {
 		TOKEN_RIGHT_SQUARE,
 		TOKEN_IF,
 		TOKEN_ELSE,
+		TOKEN_WHILE,
+		TOKEN_DO,
+		TOKEN_FOR,
 		TOKEN_SEMICOLON,
 		TOKEN_COLON,
 		TOKEN_DOT,