chickadee » srfi-51 » <args-number-limit>

<args-number-limit>parameter

<args-number-limit> should be an integer, +, -, or a boolean.

  • 1. When the <args-number-limit> is + or a positive integer, each <default> should be a list that contains default value(s), or a pair whose car is a default value and cdr is a predicate procedure.
  • 2. When the <args-number-limit> is - or a negative integer, each <default> is any scheme expression.
  • 3. When the <args-number-limit> is a boolean, each <default> is the same as 1.
  • 1. (first mode of operation)

REST-VALUES checks whether each element of the <rest-list> is a member of the corresponding <default> list, or satisfies the predicate procedure of the corresponding <default> pair, and then returns the checked element(s). If the element doesn't pass, REST-VALUES signals an error. When there are no more elements in the <rest-list>, then REST-VALUES additionally returns the car values of the remaining <default>s. On the other hand, when the number of elements of the <rest-list> are more than the number of the <default>s, the supernumerary elements are additionally returned if the <args-number-limit> is +, or its value is not less than the number of elements of the <rest-list>.

  • 2. (second mode of operation)

This is the same as the first except that REST-VALUES does not check each element of the <rest-list>, and it uses - instead of +, and an absolute value instead of a simple value as the value of <args-number-limit>.

3. (third mode of operation)

REST-VALUES checks whether any element of the <default> list is a member of the <rest-list>, or any element of the <rest-list> satisfies the predicate procedure of the <default> pair, and then returns the checked element. If the <default> doesn't pass, REST-VALUES returns the car value of the <default>. When any elements of the <rest-list> are remained after the above processing, REST-VALUES either signals an error if the <args-number-limit> is #t, or returns the remaining elements of the <rest-list> if the <args-number-limit> is #f.