Universal-transpiler

Universal-transpiler is a source-to-source compiler that translates a subset of most programming languages into several others.

The original version of this translator was written in JavaScript, but [a better version has been written in Prolog](universal-transpiler.pl).

This is some JavaScript code:

function add(a,b){
        var g = [3,4,5];
        return a+b+(g[0])+(g.length);
}

function divide(a,b){
        return a/b;
}

and this is the Java code that it generates:

public static int add(int a,int b){
        int[] g={3,4,5};
        return a+b+(g[0])+(g.length);
}

public static int divide(int a,int b){
        return a/b;
}

#How to use this translator

Install the package by typing pack-install(transpiler) in the SWI-Prolog console. Now, you can use the translator to convert JavaScript source code into Lua:

:- use_module(library(transpiler)).
:- set_prolog_flag(double_quotes,chars).
:- initialization(main).

main :- translate('function add(a,b){return a + b;}',lua,X),writeln(X).

#How to extend the translator

A limited number of translation rules are provided here, but you can easily add your own rules to universal-transpiler.pl. This is a simplified version of one of its translation rules, implementing the sine function:

%The type of this expression is double.
parentheses_expr(Data,double,sin(Var1_)) -->
{
                %The parameter of the sine function can be an integer or double.
                Var1 = expr(Data,double,Var1_)
        },
langs_to_output(Data,sin,[
['java','javascript']:
        ("Math",ws,".",ws,"sin",ws,"(",ws,Var1,ws,")"),
['lua','python']:
        ("math",python_ws,".",python_ws,"sin",python_ws,"(",python_ws,Var1,python_ws,")"),
]).