From e209eab673e0f1418e9d1b283311917275dba10f Mon Sep 17 00:00:00 2001
From: Runxi Yu <me@runxiyu.org>
Date: Sat, 15 Mar 2025 22:42:37 +0800
Subject: [PATCH] Add strerror

---
 example/get.ha       | 27 +++++++++++++++++++--------
 example/put.ha       | 25 ++++++++++++++++++-------
 lmdb/error.ha        |  8 ++++++++
 lmdb/ffi/strerror.ha |  3 +++

diff --git a/example/get.ha b/example/get.ha
index e3ba91d6f8c3b42caf74c5215e47a8a9f99a18cd..f1281ac34f5bf7a5fdea7bbbf91f414da1d9187b 100644
--- a/example/get.ha
+++ b/example/get.ha
@@ -9,27 +9,38 @@ use os;
 
 export fn main() void = {
 	if (len(os::args) != 3) {
-		abort("need two arguments (db dir, key)");
+		fmt::fprintln(os::stderr, "need two arguments (db dir, key)")!;
+		return;
 	};
 
+	match (real()) {
+	case void => void;
+	case let e: lmdb::error =>
+		fmt::fprintln(os::stderr, lmdb::strerror(e))!;
+	case let e: io::error =>
+		fmt::fprintln(os::stderr, io::strerror(e))!;
+	};
+};
+
+export fn real() (void | lmdb::error | io::error) = {
 	const key = lmdb::val{
 		mv_size = len(strings::toutf8(os::args[2])),
 		mv_data = c::unterminatedstr(os::args[2]): *opaque,
 	};
 
-	let env = lmdb::env_create()!;
+	let env = lmdb::env_create()?;
 
-	lmdb::env_open(env, os::args[1], 0, 0o644)!;
+	lmdb::env_open(env, os::args[1], 0, 0o644)?;
 
-	let txn = lmdb::txn_begin(env, 0)!;
+	let txn = lmdb::txn_begin(env, 0)?;
 
-	let dbi = lmdb::dbi_open(txn, null, lmdb_ffi::CREATE)!;
+	let dbi = lmdb::dbi_open(txn, null, lmdb_ffi::CREATE)?;
 
-	let val = lmdb::get(dbi, &key)!;
+	let val = lmdb::get(dbi, &key)?;
 
 	let data = lmdb::val_u8s(&val);
 
-	io::write(os::stdout, data)!;
+	io::write(os::stdout, data)?;
 
-	lmdb::txn_abort(txn)!;
+	lmdb::txn_abort(txn)?;
 };
diff --git a/example/put.ha b/example/put.ha
index 6eeef1acd4d4ac17a63b76a64db73c16af788eaa..945eefe058df9557e74dd9f36c3f1a3ee41214a5 100644
--- a/example/put.ha
+++ b/example/put.ha
@@ -9,9 +9,20 @@ use os;
 
 export fn main() void = {
 	if (len(os::args) != 3) {
-		abort("need two arguments (db dir, key)");
+		fmt::fprintln(os::stderr, "need two arguments (db dir, key)")!;
+		return;
+	};
+
+	match (real()) {
+	case void => void;
+	case let e: lmdb::error =>
+		fmt::fprintln(os::stderr, lmdb::strerror(e))!;
+	case let e: io::error =>
+		fmt::fprintln(os::stderr, io::strerror(e))!;
 	};
+};
 
+export fn real() (void | lmdb::error | io::error) = {
 	const key = lmdb::val {
 		mv_size = len(strings::toutf8(os::args[2])),
 		mv_data = c::unterminatedstr(os::args[2]): *opaque,
@@ -22,15 +33,15 @@ 	defer free(v);
 
 	const val = lmdb::u8s_val(v);
 
-	let env = lmdb::env_create()!;
+	let env = lmdb::env_create()?;
 
-	lmdb::env_open(env, os::args[1], 0, 0o644)!;
+	lmdb::env_open(env, os::args[1], 0, 0o644)?;
 
-	let txn = lmdb::txn_begin(env, 0)!;
+	let txn = lmdb::txn_begin(env, 0)?;
 
-	let dbi = lmdb::dbi_open(txn, null, lmdb_ffi::CREATE)!;
+	let dbi = lmdb::dbi_open(txn, null, lmdb_ffi::CREATE)?;
 
-	let val = lmdb::put(dbi, &key, &val, 0)!;
+	let val = lmdb::put(dbi, &key, &val, 0)?;
 
-	lmdb::txn_commit(txn)!;
+	lmdb::txn_commit(txn)?;
 };
diff --git a/lmdb/error.ha b/lmdb/error.ha
index 0709465d138c94fd556c3001c42daa793635c191..dda8f132759af97e803ff42f6e5b574cb168fc2d 100644
--- a/lmdb/error.ha
+++ b/lmdb/error.ha
@@ -1,2 +1,10 @@
+use lmdb::ffi;
+use types::c;
+
 // Any error returned by LMDB.
 export type error = !int;
+
+// Create a human-readable error message from an [[error]].
+export fn strerror(err: error) str = {
+	return c::tostr_unsafe(ffi::strerror(err: int));
+};
diff --git a/lmdb/ffi/strerror.ha b/lmdb/ffi/strerror.ha
new file mode 100644
index 0000000000000000000000000000000000000000..39a187b8e22eb8ba3339acd451b5419417eb1eaf
--- /dev/null
+++ b/lmdb/ffi/strerror.ha
@@ -0,0 +1,3 @@
+use types::c;
+
+export @symbol("mdb_strerror") fn strerror(err: int) *c::char;

-- 
2.48.1