From de7dc36da3542f534f90f069b1fa67f6909ab8e7 Mon Sep 17 00:00:00 2001
From: Hojun-Cho <ghwns6743@gmail.com>
Date: Thu, 4 Jun 2026 05:45:52 +0900
Subject: [PATCH] lib/regex: verbatim cast-expr appends; correct bare-decl zero
 cite (fold-2a review)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The lit/match appends went through a let-temp; the direct Hare
spelling append(insts, (r: inst_lit)) compiles and runs correctly
(probed at the real 48B-payload inst shape), so the temps were an
undocumented reshape. Void variants (skip/any) keep the typed let —
a bare type name is a symbol ref in ww — now documented at-site.
The bare-slice-decl zeroing cite pointed at shlex.ww:215, which
zeroes its header EXPLICITLY and so proves nothing; the real
mechanism is cgen.c:9836's no-rhs multi-word composite zero-fill.
---
 lib/regex/regex.ww | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/lib/regex/regex.ww b/lib/regex/regex.ww
index e3fc8d4c..247e8625 100644
--- a/lib/regex/regex.ww
+++ b/lib/regex/regex.ww
@@ -118,7 +118,8 @@ export fn finish(re: *regex) void = { };
 // runtime (#27) — the port drops every Hare free().
 export fn compile(expr: str) (regex | error | nomem) = {
 	// Hare `let insts: []inst = [];` — a bare ww slice declaration
-	// zeroes the header (cf lib/shlex/shlex.ww:215).
+	// zeroes the header (cgen.c:9836 no-rhs multi-word composite
+	// zero-fill, symmetric in cgenstmt.ww).
 	let insts: []inst;
 	let charsets: []charset;	// stays empty until the '[' fold
 	let iter: strings.iterator = strings.iter(expr);
@@ -131,6 +132,10 @@ export fn compile(expr: str) (regex | error | nomem) = {
 		if (r_idx == 0 && next is rune && (next as rune) != '^') {
 			// Bare append: ww append returns void; Hare's
 			// `append(...)?` nomem propagation is filed #36.
+			// Hare appends the bare type name (`inst_skip`) as
+			// the void-variant value; in ww that resolves as a
+			// symbol ref (cf the alloc(T) rule), so void
+			// variants go through a typed let.
 			let sk: inst_skip;
 			let v: inst = sk;
 			append(insts, v);
@@ -149,17 +154,13 @@ export fn compile(expr: str) (regex | error | nomem) = {
 			let v: inst = av;
 			append(insts, v);
 		};
-		case ']': {		// regex.ha:315-316 — literal outside a bracket
-			let v: inst = (r: inst_lit);
-			append(insts, v);
-		};
+		case ']':		// regex.ha:315-316 — literal outside a bracket
+			append(insts, (r: inst_lit));
 		case '\\', '^', '$', '[', '(', ')', '|', '{', '?', '*', '+':
 			// fold-2a boundary: regex.ha:286-459 arms deferred.
 			return "regex: metacharacter not yet ported": error;
-		case: {			// regex.ha:462-463
-			let v: inst = (r: inst_lit);
-			append(insts, v);
-		};
+		case:			// regex.ha:462-463
+			append(insts, (r: inst_lit));
 		};
 		r_idx += 1;
 	};
@@ -167,8 +168,7 @@ export fn compile(expr: str) (regex | error | nomem) = {
 	// regex.ha:475-477. `$` appends true: inst_match — deferred, so
 	// the guard can only see no-match today; kept verbatim.
 	if (insts.len == 0 || !(insts[insts.len - 1] is inst_match)) {
-		let m: inst = (false: inst_match);
-		append(insts, m);
+		append(insts, (false: inst_match));
 	};
 	// regex.ha:479-484. The alternation fixup (ha:470-473) drops with
 	// jump_idxs.