tcl-js/src/math/simplify.js

tcl-js is a tcl intepreter written completely in Typescript. It is meant to replicate the tcl-sh interpreter as closely as possible.

import { Instruction, INUMBER, IOP1, IOP2, IOP3, IVAR, IEXPR, IMEMBER } from './instruction';

export default function simplify(tokens, unaryOps, binaryOps, ternaryOps, values) {
  var nstack = [];
  var newexpression = [];
  var n1, n2, n3;
  var f;
  for (var i = 0; i < tokens.length; i++) {
    var item = tokens[i];
    var type = item.type;
    if (type === INUMBER) {
      nstack.push(item);
    } else if (type === IVAR && values.hasOwnProperty(item.value)) {
      item = new Instruction(INUMBER, values[item.value]);
      nstack.push(item);
    } else if (type === IOP2 && nstack.length > 1) {
      n2 = nstack.pop();
      n1 = nstack.pop();
      f = binaryOps[item.value];
      item = new Instruction(INUMBER, f(n1.value, n2.value));
      nstack.push(item);
    } else if (type === IOP3 && nstack.length > 2) {
      n3 = nstack.pop();
      n2 = nstack.pop();
      n1 = nstack.pop();
      if (item.value === '?') {
        nstack.push(n1.value ? n2.value : n3.value);
      } else {
        f = ternaryOps[item.value];
        item = new Instruction(INUMBER, f(n1.value, n2.value, n3.value));
        nstack.push(item);
      }
    } else if (type === IOP1 && nstack.length > 0) {
      n1 = nstack.pop();
      f = unaryOps[item.value];
      item = new Instruction(INUMBER, f(n1.value));
      nstack.push(item);
    } else if (type === IEXPR) {
      while (nstack.length > 0) {
        newexpression.push(nstack.shift());
      }
      newexpression.push(new Instruction(IEXPR, simplify(item.value, unaryOps, binaryOps, ternaryOps, values)));
    } else if (type === IMEMBER && nstack.length > 0) {
      n1 = nstack.pop();
      nstack.push(new Instruction(INUMBER, n1.value[item.value]));
    } else {
      while (nstack.length > 0) {
        newexpression.push(nstack.shift());
      }
      newexpression.push(item);
    }
  }
  while (nstack.length > 0) {
    newexpression.push(nstack.shift());
  }
  return newexpression;
}