feat: update toUserdata interface

natecraddock · natecraddock · commit edf63862ac9b · 2023-02-15T21:03:42.000-07:00
Now the function accepts a type so the return value is a typed pointer
rather than an *anyopaque. This makes the function easier to use because
the call site would always be a cast anyway.
diff --git a/src/ziglua-5.1/lib.zig b/src/ziglua-5.1/lib.zig
@@ -874,11 +874,10 @@ pub const Lua = struct {
         return error.Fail;
     }
 
-    /// If the value at the given `index` is a full userdata, returns its memory-block address
-    /// If the value is a light userdata, returns its value (a pointer)
-    /// Otherwise returns an error
-    pub fn toUserdata(lua: *Lua, index: i32) !*anyopaque {
-        if (c.lua_touserdata(lua.state, index)) |ptr| return ptr;
+    /// Returns a pointer of the given type to the userdata at the given index.
+    /// Works for both full and light userdata. Otherwise returns an error.
+    pub fn toUserdata(lua: *Lua, comptime T: type, index: i32) !*T {
+        if (c.lua_touserdata(lua.state, index)) |ptr| return opaqueCast(T, ptr);
         return error.Fail;
     }
 
diff --git a/src/ziglua-5.1/tests.zig b/src/ziglua-5.1/tests.zig
@@ -553,7 +553,7 @@ test "userdata and uservalues" {
     data.val = 1;
     std.mem.copy(u8, &data.code, "abcd");
 
-    try expectEqual(data, ziglua.opaqueCast(Data, try lua.toUserdata(1)));
+    try expectEqual(data, try lua.toUserdata(Data, 1));
     try expectEqual(@ptrCast(*const anyopaque, data), @alignCast(@alignOf(Data), try lua.toPointer(1)));
 }
 
diff --git a/src/ziglua-5.2/lib.zig b/src/ziglua-5.2/lib.zig
@@ -1054,11 +1054,10 @@ pub const Lua = struct {
         return result;
     }
 
-    /// If the value at the given `index` is a full userdata, returns its memory-block address
-    /// If the value is a light userdata, returns its value (a pointer)
-    /// Otherwise returns an error
-    pub fn toUserdata(lua: *Lua, index: i32) !*anyopaque {
-        if (c.lua_touserdata(lua.state, index)) |ptr| return ptr;
+    /// Returns a pointer of the given type to the userdata at the given index.
+    /// Works for both full and light userdata. Otherwise returns an error.
+    pub fn toUserdata(lua: *Lua, comptime T: type, index: i32) !*T {
+        if (c.lua_touserdata(lua.state, index)) |ptr| return opaqueCast(T, ptr);
         return error.Fail;
     }
 
diff --git a/src/ziglua-5.2/tests.zig b/src/ziglua-5.2/tests.zig
@@ -731,7 +731,7 @@ test "userdata and uservalues" {
     lua.getUserValue(1);
     try expectEqual(LuaType.nil, lua.typeOf(-1));
 
-    try expectEqual(data, ziglua.opaqueCast(Data, try lua.toUserdata(1)));
+    try expectEqual(data, try lua.toUserdata(Data, 1));
     try expectEqual(@ptrCast(*const anyopaque, data), @alignCast(@alignOf(Data), try lua.toPointer(1)));
 }
 
diff --git a/src/ziglua-5.3/lib.zig b/src/ziglua-5.3/lib.zig
@@ -1115,11 +1115,10 @@ pub const Lua = struct {
         return error.Fail;
     }
 
-    /// If the value at the given `index` is a full userdata, returns its memory-block address
-    /// If the value is a light userdata, returns its value (a pointer)
-    /// Otherwise returns an error
-    pub fn toUserdata(lua: *Lua, index: i32) !*anyopaque {
-        if (c.lua_touserdata(lua.state, index)) |ptr| return ptr;
+    /// Returns a pointer of the given type to the userdata at the given index.
+    /// Works for both full and light userdata. Otherwise returns an error.
+    pub fn toUserdata(lua: *Lua, comptime T: type, index: i32) !*T {
+        if (c.lua_touserdata(lua.state, index)) |ptr| return opaqueCast(T, ptr);
         return error.Fail;
     }
 
diff --git a/src/ziglua-5.3/tests.zig b/src/ziglua-5.3/tests.zig
@@ -774,7 +774,7 @@ test "userdata and uservalues" {
     try expectEqual(LuaType.number, lua.getUserValue(1));
     try expectEqual(@as(Number, 1234.56), try lua.toNumber(-1));
 
-    try expectEqual(data, ziglua.opaqueCast(Data, try lua.toUserdata(1)));
+    try expectEqual(data, try lua.toUserdata(Data, 1));
     try expectEqual(@ptrCast(*const anyopaque, data), @alignCast(@alignOf(Data), try lua.toPointer(1)));
 }
 
diff --git a/src/ziglua-5.4/lib.zig b/src/ziglua-5.4/lib.zig
@@ -1143,11 +1143,10 @@ pub const Lua = struct {
         return error.Fail;
     }
 
-    /// If the value at the given `index` is a full userdata, returns its memory-block address
-    /// If the value is a light userdata, returns its value (a pointer)
-    /// Otherwise returns an error
-    pub fn toUserdata(lua: *Lua, index: i32) !*anyopaque {
-        if (c.lua_touserdata(lua.state, index)) |ptr| return ptr;
+    /// Returns a pointer of the given type to the userdata at the given index.
+    /// Works for both full and light userdata. Otherwise returns an error.
+    pub fn toUserdata(lua: *Lua, comptime T: type, index: i32) !*T {
+        if (c.lua_touserdata(lua.state, index)) |ptr| return opaqueCast(T, ptr);
         return error.Fail;
     }
 
diff --git a/src/ziglua-5.4/tests.zig b/src/ziglua-5.4/tests.zig
@@ -819,7 +819,7 @@ test "userdata and uservalues" {
     try expectError(error.Fail, lua.setIndexUserValue(1, 3));
     try expectError(error.Fail, lua.getIndexUserValue(1, 3));
 
-    try expectEqual(data, ziglua.opaqueCast(Data, try lua.toUserdata(1)));
+    try expectEqual(data, try lua.toUserdata(Data, 1));
     try expectEqual(@ptrCast(*const anyopaque, data), @alignCast(@alignOf(Data), try lua.toPointer(1)));
 }
 

Original file line number	Diff line number	Diff line change
`@@ -874,11 +874,10 @@ pub const Lua = struct {`
`874`	`874`	`return error.Fail;`
`875`	`875`	`}`
`876`	`876`
`877`		- /// If the value at the given `index` is a full userdata, returns its memory-block address
`878`		`- /// If the value is a light userdata, returns its value (a pointer)`
`879`		`- /// Otherwise returns an error`
`880`		`- pub fn toUserdata(lua: Lua, index: i32) !anyopaque {`
`881`		`- if (c.lua_touserdata(lua.state, index)) \|ptr\| return ptr;`
	`877`	`+ /// Returns a pointer of the given type to the userdata at the given index.`
	`878`	`+ /// Works for both full and light userdata. Otherwise returns an error.`
	`879`	`+ pub fn toUserdata(lua: Lua, comptime T: type, index: i32) !T {`
	`880`	`+ if (c.lua_touserdata(lua.state, index)) \|ptr\| return opaqueCast(T, ptr);`
`882`	`881`	`return error.Fail;`
`883`	`882`	`}`
`884`	`883`
Original file line number	Diff line number	Diff line change
`@@ -553,7 +553,7 @@ test "userdata and uservalues" {`
`553`	`553`	`data.val = 1;`
`554`	`554`	`std.mem.copy(u8, &data.code, "abcd");`
`555`	`555`
`556`		`- try expectEqual(data, ziglua.opaqueCast(Data, try lua.toUserdata(1)));`
	`556`	`+ try expectEqual(data, try lua.toUserdata(Data, 1));`
`557`	`557`	`try expectEqual(@ptrCast(*const anyopaque, data), @alignCast(@alignOf(Data), try lua.toPointer(1)));`
`558`	`558`	`}`
`559`	`559`
Original file line number	Diff line number	Diff line change
`@@ -1054,11 +1054,10 @@ pub const Lua = struct {`
`1054`	`1054`	`return result;`
`1055`	`1055`	`}`
`1056`	`1056`
`1057`		- /// If the value at the given `index` is a full userdata, returns its memory-block address
`1058`		`- /// If the value is a light userdata, returns its value (a pointer)`
`1059`		`- /// Otherwise returns an error`
`1060`		`- pub fn toUserdata(lua: Lua, index: i32) !anyopaque {`
`1061`		`- if (c.lua_touserdata(lua.state, index)) \|ptr\| return ptr;`
	`1057`	`+ /// Returns a pointer of the given type to the userdata at the given index.`
	`1058`	`+ /// Works for both full and light userdata. Otherwise returns an error.`
	`1059`	`+ pub fn toUserdata(lua: Lua, comptime T: type, index: i32) !T {`
	`1060`	`+ if (c.lua_touserdata(lua.state, index)) \|ptr\| return opaqueCast(T, ptr);`
`1062`	`1061`	`return error.Fail;`
`1063`	`1062`	`}`
`1064`	`1063`
Original file line number	Diff line number	Diff line change
`@@ -731,7 +731,7 @@ test "userdata and uservalues" {`
`731`	`731`	`lua.getUserValue(1);`
`732`	`732`	`try expectEqual(LuaType.nil, lua.typeOf(-1));`
`733`	`733`
`734`		`- try expectEqual(data, ziglua.opaqueCast(Data, try lua.toUserdata(1)));`
	`734`	`+ try expectEqual(data, try lua.toUserdata(Data, 1));`
`735`	`735`	`try expectEqual(@ptrCast(*const anyopaque, data), @alignCast(@alignOf(Data), try lua.toPointer(1)));`
`736`	`736`	`}`
`737`	`737`
Original file line number	Diff line number	Diff line change
`@@ -1115,11 +1115,10 @@ pub const Lua = struct {`
`1115`	`1115`	`return error.Fail;`
`1116`	`1116`	`}`
`1117`	`1117`
`1118`		- /// If the value at the given `index` is a full userdata, returns its memory-block address
`1119`		`- /// If the value is a light userdata, returns its value (a pointer)`
`1120`		`- /// Otherwise returns an error`
`1121`		`- pub fn toUserdata(lua: Lua, index: i32) !anyopaque {`
`1122`		`- if (c.lua_touserdata(lua.state, index)) \|ptr\| return ptr;`
	`1118`	`+ /// Returns a pointer of the given type to the userdata at the given index.`
	`1119`	`+ /// Works for both full and light userdata. Otherwise returns an error.`
	`1120`	`+ pub fn toUserdata(lua: Lua, comptime T: type, index: i32) !T {`
	`1121`	`+ if (c.lua_touserdata(lua.state, index)) \|ptr\| return opaqueCast(T, ptr);`
`1123`	`1122`	`return error.Fail;`
`1124`	`1123`	`}`
`1125`	`1124`
Original file line number	Diff line number	Diff line change
`@@ -774,7 +774,7 @@ test "userdata and uservalues" {`
`774`	`774`	`try expectEqual(LuaType.number, lua.getUserValue(1));`
`775`	`775`	`try expectEqual(@as(Number, 1234.56), try lua.toNumber(-1));`
`776`	`776`
`777`		`- try expectEqual(data, ziglua.opaqueCast(Data, try lua.toUserdata(1)));`
	`777`	`+ try expectEqual(data, try lua.toUserdata(Data, 1));`
`778`	`778`	`try expectEqual(@ptrCast(*const anyopaque, data), @alignCast(@alignOf(Data), try lua.toPointer(1)));`
`779`	`779`	`}`
`780`	`780`
Original file line number	Diff line number	Diff line change
`@@ -1143,11 +1143,10 @@ pub const Lua = struct {`
`1143`	`1143`	`return error.Fail;`
`1144`	`1144`	`}`
`1145`	`1145`
`1146`		- /// If the value at the given `index` is a full userdata, returns its memory-block address
`1147`		`- /// If the value is a light userdata, returns its value (a pointer)`
`1148`		`- /// Otherwise returns an error`
`1149`		`- pub fn toUserdata(lua: Lua, index: i32) !anyopaque {`
`1150`		`- if (c.lua_touserdata(lua.state, index)) \|ptr\| return ptr;`
	`1146`	`+ /// Returns a pointer of the given type to the userdata at the given index.`
	`1147`	`+ /// Works for both full and light userdata. Otherwise returns an error.`
	`1148`	`+ pub fn toUserdata(lua: Lua, comptime T: type, index: i32) !T {`
	`1149`	`+ if (c.lua_touserdata(lua.state, index)) \|ptr\| return opaqueCast(T, ptr);`
`1151`	`1150`	`return error.Fail;`
`1152`	`1151`	`}`
`1153`	`1152`
Original file line number	Diff line number	Diff line change
`@@ -819,7 +819,7 @@ test "userdata and uservalues" {`
`819`	`819`	`try expectError(error.Fail, lua.setIndexUserValue(1, 3));`
`820`	`820`	`try expectError(error.Fail, lua.getIndexUserValue(1, 3));`
`821`	`821`
`822`		`- try expectEqual(data, ziglua.opaqueCast(Data, try lua.toUserdata(1)));`
	`822`	`+ try expectEqual(data, try lua.toUserdata(Data, 1));`
`823`	`823`	`try expectEqual(@ptrCast(*const anyopaque, data), @alignCast(@alignOf(Data), try lua.toPointer(1)));`
`824`	`824`	`}`
`825`	`825`