fix(gen-zig): for-range emits its start expression, not the loop variable

NOW.md

@@ -2,6 +2,12 @@
 
 Last updated: 2026-08-08
 
+## gen-zig: for-range start expression, not the loop variable (Closes #1942)
+
+- `for i in 0..10` emitted `for (i..10) |i|` -- gen_for_range_stmt wrote the loop VARIABLE where the range start belongs; now emits children[0]
+- Surfaced by the tri-net testbench transcription (first real for-range uses in the zig corpus)
+- FROZEN_HASH resealed
+
 ## parser: silent statement drop is DEAD -- malformed input hard-errors (Closes #1940)
 
 - Statement-level and module-level "recovery" silently DROPPED malformed statements/declarations (fn bodies became unimplemented stubs, whole fns vanished); every drop site now returns a hard parse error with fn name + line

bootstrap/src/compiler.rs

@@ -4176,11 +4176,16 @@ impl Codegen {
 
     fn gen_for_range_stmt(&mut self, node: &Node) {
         self.write_indent();
-        self.write(&format!("for ({}..", node.name));
+        // children[0] is the range START expression; the old emitter wrote
+        // the LOOP VARIABLE there (`for (i..10) |i|`) -- an undeclared
+        // identifier in Zig for any range not starting at the variable name.
+        self.write("for (");
         if node.children.len() >= 2 {
+            self.gen_expr(&node.children[0]);
+            self.write("..");
             self.gen_expr(&node.children[1]);
             self.write(") |");
-            self.write(&node.name);
+            self.write(&Self::zig_ident(&node.name));
             self.write("|");
         }
         self.write_line(" {");

bootstrap/stage0/FROZEN_HASH

@@ -1 +1 @@
-4d10feb127277a49d610a3f22fd8350466dd7460a6ee4a831b872b6f60e5da25
+d61af1df5f2b75cc5fb3ff91e4e0289c093b4c1fd1b46f7483c082c7393760b2

docs/NOW.md

@@ -2,6 +2,12 @@
 
 Last updated: 2026-08-08
 
+## gen-zig: for-range start expression, not the loop variable (Closes #1942)
+
+- `for i in 0..10` emitted `for (i..10) |i|` -- gen_for_range_stmt wrote the loop VARIABLE where the range start belongs; now emits children[0]
+- Surfaced by the tri-net testbench transcription (first real for-range uses in the zig corpus)
+- FROZEN_HASH resealed
+
 ## parser: silent statement drop is DEAD -- malformed input hard-errors (Closes #1940)
 
 - Statement-level and module-level "recovery" silently DROPPED malformed statements/declarations (fn bodies became unimplemented stubs, whole fns vanished); every drop site now returns a hard parse error with fn name + line