From 9de1d1752970ba09f9d0b77a8ae6c0d4b8910bc7 Mon Sep 17 00:00:00 2001
From: Hannes Bredberg <hannesbredberg@gmail.com>
Date: Thu, 5 Oct 2023 01:36:00 +0200
Subject: [PATCH] Parse while expressions

---
 selfhost/parser.n    | 13 +++++++++++++
 selfhost/tokenizer.n | 10 ++++++++++
 2 files changed, 23 insertions(+)

diff --git a/selfhost/parser.n b/selfhost/parser.n
index ff02894..ea54c8d 100644
--- a/selfhost/parser.n
+++ b/selfhost/parser.n
@@ -38,6 +38,10 @@ const NodeType = enum(u8) {
     // payload: loop body
     @"loop",
 
+    // idx - 1: condition
+    // payload: while body
+    @"while",
+
     // token is the keyword
     // payload is optional value
     return_expr,
@@ -297,6 +301,15 @@ fn parse_primary_expression(context: *ParserContext, require: bool, precedence:
         node_payload.get(result).* = parse_block(context);
         return result;
     }
+    else if(p == .while_keyword) {
+        const token = context.advance();
+        context.expect("Expected '(' after 'while'".&, .@"(");
+        parse_expression(context);
+        const result = add_with_token(token, .@"while");
+        context.expect("Expected ')' after while condition".&, .@")");
+        node_payload.get(result).* = parse_expression_with_precedence(context, true, precedence);
+        return result;
+    }
     else if(p == .@"{") {
         const result = add_with_token(context.current_token, .block);
         node_payload.get(result).* = parse_block(context);
diff --git a/selfhost/tokenizer.n b/selfhost/tokenizer.n
index 491cf73..209a8da 100644
--- a/selfhost/tokenizer.n
+++ b/selfhost/tokenizer.n
@@ -37,6 +37,7 @@ const TokenType = enum(u8) {
     unreachable_keyword,
     var_keyword,
     //volatile_keyword,
+    while_keyword,
     __keyword,
 
     //bool_keyword,
@@ -312,6 +313,15 @@ fn init() void {
         }
     }.&;
 
+    token_handlers['w'] = fn(context: *TokenizationContext) void {
+        if(context.matches("while".&)) {
+            context.add_token_advance(.while_keyword, 5);
+        }
+        else {
+            ident_handler(context);
+        }
+    }.&;
+
     {
         var ch: u32 = 0;
         loop(ch <= 0xFF) {