character-sheet/src/operations/Calculate.js

CharacterSheet library for assembling relationships between stats and modifiers.

import RegisterWith from './util/RegisterWith';
import Operation from '../Operation';

class Calculate extends Operation {
  static type = 'calculate';

  _selectors = [];
  _fn = null;

  constructor({ selectors = [], fn }) {
    super(...arguments);

    this._selectors = selectors;
    this._fn = fn;
  }

  static from(addOperation) {
    let o = new Calculate(addOperation.fn);
    return o;
  }

  import(addOperation) {
    this._fn = Function(addOperation.fn);
    this._selectors = addOperation.selectors;
  }

  export() {
    return {
      type: Calculate.type,
      selectors: this._selectors,
      fn: this._fn.toString()
    };
  }

  transform(value, resolver) {
    return this._fn(value, ...this._selectors.map(resolver));
  }
}

export default RegisterWith(Operation)(Calculate);