Pointers for sweet.js

1README.md

Pointers for sweet.js

Usage

ptr test = 5;

console.log(acc test);

function process(testPtr) {
  acc testPtr = acc testPtr + 2;
}

process(test);

console.log(acc test);

var realTest = acc test;

console.log(realTest);

pointers.sjs

syntax ptr = function(ctx) {
  let ident = ctx.next().value;
  ctx.next(); // eat `=`
  let init = ctx.expand('expr').value;

  let varName = "";
  let possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

  for(let i=0; i < 20; i++)
    varName += possible.charAt(Math.floor(Math.random() * possible.length));

  let dummy = #`dummy`.get(0);

  return #`
    let ${dummy.fromIdentifier(varName)} = ${init}

    let ${ident} = function(val) {
      if (arguments.length > 0) {${dummy.fromIdentifier(varName)} = val; return;}
      return ${dummy.fromIdentifier(varName)};
    }`
}

syntax acc = function(ctx) {
  let pointer = ctx.next().value;
  let equals = ctx.next().value;
  let value = ctx.expand('expr').value;
  let dummy = #`dummy`.get(0);

  if (equals === null || value === null || (equals.val() === ";" && value === null)) {
    return #`${dummy.fromIdentifier(pointer.val())}()`;
  } else if (equals.val() === '+' || equals.val() === '*' || equals.val() === '-' || equals.val() === '/' || equals.val() === '%' || (equals.val() === ";" && value !== null)) {
    return #`${dummy.fromIdentifier(pointer.val())}() ${equals} ${value}`;
  } else if (equals.val() !== "=") {
    throw new TypeError("Operators other than '=' unsupported! Line: " + pointer.lineNumber() + " Operator: " + equals.val());
    return #``;
  } else if (pointer === null || !pointer.isIdentifier()) {
    throw new TypeError("Must specify pointer! Line: " + pointer.lineNumber());
    return #``;
  } else {
    return #`${dummy.fromIdentifier(pointer.val())}(${value})`;
  }
}