121 lines
3.9 KiB
Markdown
121 lines
3.9 KiB
Markdown
|
# LuaTables
|
||
|
|
|
||
|
|
LuaTables has the aim to make accessing of Lua values from C++ as simple as
|
||
|
|
possible and to use Lua scripts instead of .ini, or JSON files as a
|
||
|
|
configuration file format.
|
||
|
|
|
||
|
|
As a side effect LuaTables can also be used as an intuitive bridge to
|
||
|
|
access Lua values from a given Lua virtual machine.
|
||
|
|
|
||
|
|
# Usage
|
||
|
|
|
||
|
|
Navigation to a Lua value is done using std::map-like accessors. E.g. for a
|
||
|
|
Lua file:
|
||
|
|
|
||
|
|
:::lua
|
||
|
|
-- myfile.lua
|
||
|
|
person = {
|
||
|
|
name = "James",
|
||
|
|
height = 1.87,
|
||
|
|
address = {
|
||
|
|
country = "United Kingdom"
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return person
|
||
|
|
|
||
|
|
the contents can be retrieved from C++ using LuaTables using:
|
||
|
|
|
||
|
|
:::c++
|
||
|
|
LuaTable ltable = LuaTable::fromFile("myfile.lua")
|
||
|
|
|
||
|
|
std::string name = ltable["name"].get<std::string> ("Unknown");
|
||
|
|
double height = ltable["id"].get<double> (-1.);
|
||
|
|
std::string country = ltable["address"]["country"].get<std::string> ("Unknown");
|
||
|
|
|
||
|
|
the arguments to the function .get<type>(value) are default values that are
|
||
|
|
returned if the value could not be found.
|
||
|
|
|
||
|
|
# Serializing Custom Data Types
|
||
|
|
|
||
|
|
LuaTables++ can be easily extended to allow reading and writing of custom
|
||
|
|
data types. For this two functions have to be provided:
|
||
|
|
|
||
|
|
* ```LuaTableNode::getDefault<CustomType>(const CustomType &default_value)```
|
||
|
|
to read values from a LuaTable and
|
||
|
|
* ```LuaTableNode::set<CustomType>(const CustomType &value)``` to serialize data into a LuaTable.
|
||
|
|
|
||
|
|
## Example:
|
||
|
|
|
||
|
|
Given the data struct:
|
||
|
|
|
||
|
|
:::c++
|
||
|
|
struct CustomType {
|
||
|
|
string name;
|
||
|
|
double age;
|
||
|
|
bool drunken;
|
||
|
|
double position[3];
|
||
|
|
};
|
||
|
|
|
||
|
|
the two functions can be implemented as:
|
||
|
|
|
||
|
|
:::c++
|
||
|
|
template<> CustomType LuaTableNode::getDefault<CustomType>(const CustomType &default_value) {
|
||
|
|
CustomType result = default_value;
|
||
|
|
|
||
|
|
if (exists()) {
|
||
|
|
LuaTable custom_table = stackQueryTable();
|
||
|
|
|
||
|
|
result.name = custom_table["name"].get<std::string>();
|
||
|
|
result.age = custom_table["age"];
|
||
|
|
result.drunken = custom_table["drunken"];
|
||
|
|
result.position[0] = custom_table["position"][1];
|
||
|
|
result.position[1] = custom_table["position"][2];
|
||
|
|
result.position[2] = custom_table["position"][3];
|
||
|
|
}
|
||
|
|
|
||
|
|
stackRestore();
|
||
|
|
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
|
||
|
|
template<> void LuaTableNode::set<CustomType>(const CustomType &value) {
|
||
|
|
LuaTable custom_table = stackCreateLuaTable();
|
||
|
|
|
||
|
|
// set the fields of the custom type
|
||
|
|
custom_table["name"] = value.name;
|
||
|
|
custom_table["age"] = value.age;
|
||
|
|
custom_table["drunken"] = value.drunken;
|
||
|
|
custom_table["position"][1] = value.position[0];
|
||
|
|
custom_table["position"][2] = value.position[1];
|
||
|
|
custom_table["position"][3] = value.position[2];
|
||
|
|
}
|
||
|
|
|
||
|
|
# Licensing
|
||
|
|
|
||
|
|
The library is published under the zlib free software license. Here is the
|
||
|
|
full license text:
|
||
|
|
|
||
|
|
LuaTables++
|
||
|
|
Copyright (c) 2013-2014 Martin Felis <martin@fyxs.org>.
|
||
|
|
All rights reserved.
|
||
|
|
|
||
|
|
Permission is hereby granted, free of charge, to any person obtaining
|
||
|
|
a copy of this software and associated documentation files (the
|
||
|
|
"Software"), to deal in the Software without restriction, including
|
||
|
|
without limitation the rights to use, copy, modify, merge, publish,
|
||
|
|
distribute, sublicense, and/or sell copies of the Software, and to
|
||
|
|
permit persons to whom the Software is furnished to do so, subject to
|
||
|
|
the following conditions:
|
||
|
|
|
||
|
|
The above copyright notice and this permission notice shall be
|
||
|
|
included in all copies or substantial portions of the Software.
|
||
|
|
|
||
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
||
|
|
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
||
|
|
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
|
||
|
|
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
|
||
|
|
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
|
||
|
|
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
|
||
|
|
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|