add *Ex variants of pushString and pushBytes

I never care for the return value of this function, so writing _ = gets
tedious. This adds two new versions that return the value, and the
shorter non *Ex functions return void. This makes the common case
easier, but the option to access the return is still available. This
will be applied to other similar functions in the API.

Author: natecraddock

src/tests.zig

@@ -253,9 +253,12 @@ test "type of and getting values" {
     lua.pushNil();
     lua.pushNumber(0.1);
     _ = lua.pushThread();
-    _ = lua.pushString("all your codebase are belong to us");
+    try expectEqualStrings(
+        "all your codebase are belong to us",
+        lua.pushStringEx("all your codebase are belong to us"),
+    );
     lua.pushFunction(ziglua.wrap(add));
-    _ = lua.pushBytes("hello world");
+    try expectEqualStrings("hello world", lua.pushBytesEx("hello world"));
     _ = lua.pushFString("%s %s %d", .{ "hello", "world", @as(i32, 10) });
     lua.pushValue(1);
 
@@ -496,7 +499,7 @@ test "global table" {
     lua.pushGlobalTable();
 
     // find the print function
-    _ = lua.pushString("print");
+    lua.pushString("print");
     try expectEqual(LuaType.function, lua.getTable(-2));
 
     // index the global table in the global table
@@ -585,9 +588,9 @@ test "concat" {
     var lua = try Lua.init(testing.allocator);
     defer lua.deinit();
 
-    _ = lua.pushString("hello ");
+    lua.pushString("hello ");
     lua.pushNumber(10);
-    _ = lua.pushString(" wow!");
+    lua.pushString(" wow!");
     lua.concat(3);
 
     try expectEqualStrings("hello 10.0 wow!", try lua.toBytes(-1));
@@ -635,22 +638,22 @@ test "table access" {
     try expectEqual(LuaType.string, lua.rawGetIndex(1, 1));
     try expectEqualStrings("first", try lua.toBytes(-1));
 
-    _ = lua.pushString("key");
+    lua.pushString("key");
     try expectEqual(LuaType.string, lua.getTable(1));
     try expectEqualStrings("value", try lua.toBytes(-1));
 
-    _ = lua.pushString("other one");
+    lua.pushString("other one");
     try expectEqual(LuaType.number, lua.rawGetTable(1));
     try expectEqual(@as(Integer, 1234), try lua.toInteger(-1));
 
     // a.name = "ziglua"
-    _ = lua.pushString("name");
-    _ = lua.pushString("ziglua");
+    lua.pushString("name");
+    lua.pushString("ziglua");
     lua.setTable(1);
 
     // a.lang = "zig"
-    _ = lua.pushString("lang");
-    _ = lua.pushString("zig");
+    lua.pushString("lang");
+    lua.pushString("zig");
     lua.rawSetTable(1);
 
     try expectError(Error.Fail, lua.getMetatable(1));
@@ -800,7 +803,7 @@ test "userdata and uservalues" {
     lua.pushNumber(1234.56);
     try lua.setIndexUserValue(1, 1);
 
-    _ = lua.pushString("test string");
+    lua.pushString("test string");
     try lua.setIndexUserValue(1, 2);
 
     try expectEqual(LuaType.number, try lua.getIndexUserValue(1, 1));
@@ -881,7 +884,7 @@ test "registry" {
     const key = "mykey";
 
     // store a string in the registry
-    _ = lua.pushString("hello there");
+    lua.pushString("hello there");
     lua.rawSetPtr(ziglua.registry_index, key);
 
     // get key from the registry
@@ -926,7 +929,7 @@ test "raise error" {
 
     const makeError = struct {
         fn inner(l: *Lua) i32 {
-            _ = l.pushString("makeError made an error");
+            l.pushString("makeError made an error");
             l.raiseError();
             return 0;
         }
@@ -941,7 +944,7 @@ fn continuation(l: *Lua, status: ziglua.Status, ctx: isize) i32 {
     _ = status;
 
     if (ctx == 5) {
-        _ = l.pushString("done");
+        l.pushString("done");
         return 1;
     } else {
         // yield the current context value
@@ -1168,7 +1171,7 @@ test "aux check functions" {
     lua.pushFunction(function);
     lua.pushNil();
     lua.pushInteger(3);
-    _ = lua.pushBytes("hello world");
+    lua.pushBytes("hello world");
     lua.protectedCall(3, 0, 0) catch {
         try expectEqualStrings("bad argument #4 to '?' (number expected, got no value)", try lua.toBytes(-1));
         lua.pop(-1);
@@ -1177,7 +1180,7 @@ test "aux check functions" {
     lua.pushFunction(function);
     lua.pushNil();
     lua.pushInteger(3);
-    _ = lua.pushBytes("hello world");
+    lua.pushBytes("hello world");
     lua.pushNumber(4);
     lua.protectedCall(4, 0, 0) catch {
         try expectEqualStrings("bad argument #5 to '?' (string expected, got no value)", try lua.toBytes(-1));
@@ -1187,9 +1190,9 @@ test "aux check functions" {
     lua.pushFunction(function);
     lua.pushNil();
     lua.pushInteger(3);
-    _ = lua.pushBytes("hello world");
+    lua.pushBytes("hello world");
     lua.pushNumber(4);
-    _ = lua.pushString("hello world");
+    lua.pushString("hello world");
     lua.protectedCall(5, 0, 0) catch {
         try expectEqualStrings("bad argument #6 to '?' (boolean expected, got no value)", try lua.toBytes(-1));
         lua.pop(-1);
@@ -1198,9 +1201,9 @@ test "aux check functions" {
     lua.pushFunction(function);
     lua.pushNil();
     lua.pushInteger(3);
-    _ = lua.pushBytes("hello world");
+    lua.pushBytes("hello world");
     lua.pushNumber(4);
-    _ = lua.pushString("hello world");
+    lua.pushString("hello world");
     lua.pushBoolean(true);
     lua.protectedCall(6, 0, 0) catch {
         try expectEqualStrings("bad argument #6 to '?' (boolean expected, got no value)", try lua.toBytes(-1));
@@ -1210,9 +1213,9 @@ test "aux check functions" {
     lua.pushFunction(function);
     lua.pushNil();
     lua.pushInteger(3);
-    _ = lua.pushBytes("hello world");
+    lua.pushBytes("hello world");
     lua.pushNumber(4);
-    _ = lua.pushString("hello world");
+    lua.pushString("hello world");
     lua.pushBoolean(true);
     try lua.protectedCall(6, 0, 0);
 }

src/ziglua.zig

@@ -783,9 +783,14 @@ pub const Lua = struct {
         c.lua_pushlightuserdata(lua.state, ptr);
     }
 
+    /// Pushes a slice of bytes onto the stack
+    pub fn pushBytes(lua: *Lua, bytes: []const u8) void {
+        _ = lua.pushBytesEx(bytes);
+    }
+
     /// Pushes the bytes onto the stack. Returns a slice pointing to Lua's internal copy of the string
-    pub fn pushBytes(lua: *Lua, str: []const u8) []const u8 {
-        return c.lua_pushlstring(lua.state, str.ptr, str.len)[0..str.len];
+    pub fn pushBytesEx(lua: *Lua, bytes: []const u8) []const u8 {
+        return c.lua_pushlstring(lua.state, bytes.ptr, bytes.len)[0..bytes.len];
     }
 
     /// Pushes a nil value onto the stack
@@ -798,11 +803,16 @@ pub const Lua = struct {
         c.lua_pushnumber(lua.state, n);
     }
 
+    /// Pushes a zero-terminated string on to the stack
+    pub fn pushString(lua: *Lua, str: [:0]const u8) void {
+        _ = lua.pushStringEx(str);
+    }
+
     /// Pushes a zero-terminated string onto the stack
     /// Lua makes a copy of the string so `str` may be freed immediately after return
     /// Returns a pointer to the internal Lua string
-    pub fn pushString(lua: *Lua, str: []const u8) []const u8 {
-        return c.lua_pushstring(lua.state, str.ptr).?[0..str.len];
+    pub fn pushStringEx(lua: *Lua, str: [:0]const u8) [:0]const u8 {
+        return c.lua_pushstring(lua.state, str.ptr).?[0..str.len :0];
     }
 
     /// Pushes this thread onto the stack