module Chervil
  RSpec.describe Interpreter do
    def interpret(source, env)
      lexer = Lexer.new(source)
      tree = Parser.new(lexer).parse
      Interpreter.new(tree, env).interpret
    end

    it 'interprets a definition and variable usage' do
      env = Env.new
      interpret('(define x 5)', env)
      expect(env.get("x")).to eq(AST::Number.new(5.0))
      expect(interpret('x', env).first).to eq(5.0)
    end
  end
end