chervil/lib/chervil/ast/function.rb

module Chervil::AST
  class Function
    attr_reader :name
    attr_reader :params
    attr_reader :body

    def initialize(name, params, body)
      @name = name
      @params = params
      @body = body
    end

    def ==(other)
      @name == other.name && @params == other.params && @body == other.body
    end

    def evaluate(env)
      self
    end

    def call(args)
      unless @params.size == args.size
        raise "Expected #{params.size} arguments but received #{args.size}"
      end

      env = ::Chervil::Env.new
      @params.zip(args).each do |key, value|
        env.set(key.name, value)
      end

      current_expr = nil
      @body.each do |expr|
        current_expr = expr.evaluate(env)
      end

      current_expr
    end

    def to_s
      "<function: #{@name.name}(#{@params.map(&:name).join(' ')})>"
    end
  end
end