mathjs/lib/function/expression/compile.js

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser and offers an integrated solution to work with numbers, big numbers, complex numbers, units, and matrices.

module.exports = function (math, config) {
  var util = require('../../util/index'),
      _parse = require('../../expression/parse'),

      collection = require('../../type/collection'),

      isString = util.string.isString,
      isCollection = collection.isCollection;

  /**
   * Parse and compile an expression.
   * Returns a an object with a function `eval([scope])` to evaluate the
   * compiled expression.
   *
   * Syntax:
   *
   *     var code = math.compile(expr)
   *     var codes = math.compile([expr1, expr2, expr3, ...])
   *
   * Example:
   *
   *     var code = math.compile('sqrt(3^2 + 4^2)');
   *     code.eval(); // 5
   *
   *     var scope = {a: 3, b: 4}
   *     var code = math.compile('a * b'); // 12
   *     code.eval(scope); // 12
   *     scope.a = 5;
   *     code.eval(scope); // 20
   *
   *     var nodes = math.compile(['a = 3', 'b = 4', 'a * b']);
   *     nodes[2].eval(); // 12
   *
   * @param {String | String[] | Matrix} expr
   * @return {Object | Object[]} code
   * @throws {Error}
   */
  math.compile = function compile (expr) {
    if (arguments.length != 1) {
      throw new math.error.ArgumentsError('compile', arguments.length, 1);
    }

    if (isString(expr)) {
      // evaluate a single expression
      return _parse(expr).compile(math);
    }
    else if (isCollection(expr)) {
      // evaluate an array or matrix with expressions
      return collection.deepMap(expr, function (elem) {
        return _parse(elem).compile(math);
      });
    }
    else {
      // oops
      throw new TypeError('String, array, or matrix expected');
    }
  }
};