const Env = require('./env')
const Evaluator = require('./evaluator')
const Lexer = require('./lexer')
const OsloError = require('./osloError')
const Parser = require('./parser')

module.exports = function oslo(source, context) {
  const lexer = new Lexer()
  const tokens = lexer.scan(source)

  const parser = new Parser()
  const tree = parser.parse(tokens)

  if (tree.error) {
    return tree.error
  }

  const evaluator = new Evaluator()
  const evaluatedTree = evaluator.eval(tree, new Env())

  if (evaluatedTree.constructor == OsloError) {
    return evaluatedTree
  }

  return ''
}