chervil/lib/chervil/ast/application.rb

module Chervil::AST
  class Application
    attr_reader :expr
    attr_reader :arguments

    def initialize(expr, arguments)
      @expr = expr
      @arguments = arguments
    end

    def ==(other)
      @expr == other.expr && @arguments == other.arguments
    end

    def evaluate(env)
      if @expr.class == Identifier
        function = env.get(@expr.name)

        if function.nil?
          ::Chervil::Error.new("Unbound variable #{@expr.name}")
        else
          function.call(@arguments.map { |arg| arg.evaluate(env) }, env)
        end
      end
    end
  end
end