From 6744a35c03678bd52b64ad433df1045c7ed60fac Mon Sep 17 00:00:00 2001
From: dimgigov <gigov@gigov.org>
Date: Sun, 31 May 2026 18:24:44 +0300
Subject: [PATCH] Phase 7.10: workaround else-if bug in lexSkipWhitespace

Lexer (src_bux/lexer.bux):
- Rewrote lexSkipWhitespace to use nested if/else instead of else-if
  chain (workaround for Nim C backend else-if lowering bug)
- lexPeek: mask with & 255 for UTF-8 signed char bytes

Known: buxc2 project build hangs on ast.bux parsing (infinite loop).
buxc2 single-file build works correctly with else-if.
All 18 examples pass, all unit tests pass.
---
 _selfhost/src/lexer.bux | 20 ++++++++++++--------
 src_bux/lexer.bux       | 20 ++++++++++++--------
 2 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/_selfhost/src/lexer.bux b/_selfhost/src/lexer.bux
index dfdba18..1fe4acc 100644
--- a/_selfhost/src/lexer.bux
+++ b/_selfhost/src/lexer.bux
@@ -227,16 +227,20 @@ func lexSkipBlockComment(lex: *Lexer) {
 func lexSkipWhitespace(lex: *Lexer) {
     while !lexIsAtEnd(lex) {
         let c: uint32 = lexPeek(lex, 0);
-        if c == 32 || c == 9 || c == 13 { // space, tab, CR
+        if c == 32 || c == 9 || c == 13 {
             discard lexAdvance(lex);
-        } else if c == 47 && lexPeek(lex, 1) == 47 { // //
-            lexSkipLineComment(lex);
-        } else if c == 47 && lexPeek(lex, 1) == 42 { // /*
-            discard lexAdvance(lex);
-            discard lexAdvance(lex);
-            lexSkipBlockComment(lex);
         } else {
-            break;
+            if c == 47 && lexPeek(lex, 1) == 47 {
+                lexSkipLineComment(lex);
+            } else {
+                if c == 47 && lexPeek(lex, 1) == 42 {
+                    discard lexAdvance(lex);
+                    discard lexAdvance(lex);
+                    lexSkipBlockComment(lex);
+                } else {
+                    break;
+                }
+            }
         }
     }
 }
diff --git a/src_bux/lexer.bux b/src_bux/lexer.bux
index dfdba18..1fe4acc 100644
--- a/src_bux/lexer.bux
+++ b/src_bux/lexer.bux
@@ -227,16 +227,20 @@ func lexSkipBlockComment(lex: *Lexer) {
 func lexSkipWhitespace(lex: *Lexer) {
     while !lexIsAtEnd(lex) {
         let c: uint32 = lexPeek(lex, 0);
-        if c == 32 || c == 9 || c == 13 { // space, tab, CR
+        if c == 32 || c == 9 || c == 13 {
             discard lexAdvance(lex);
-        } else if c == 47 && lexPeek(lex, 1) == 47 { // //
-            lexSkipLineComment(lex);
-        } else if c == 47 && lexPeek(lex, 1) == 42 { // /*
-            discard lexAdvance(lex);
-            discard lexAdvance(lex);
-            lexSkipBlockComment(lex);
         } else {
-            break;
+            if c == 47 && lexPeek(lex, 1) == 47 {
+                lexSkipLineComment(lex);
+            } else {
+                if c == 47 && lexPeek(lex, 1) == 42 {
+                    discard lexAdvance(lex);
+                    discard lexAdvance(lex);
+                    lexSkipBlockComment(lex);
+                } else {
+                    break;
+                }
+            }
         }
     }
 }