the little scheme

Introduction

scheme, a dialect of lisp.

Notes

  • The law of Car
    The primitive car is defined only for non-empty lists. The cdr of any non-empty list is always another list.
  • The law of Cons
    The primitive takes two arguments. The second argument to must be a list. The result is a list.
  • The law of Null?
    The primitive null? is defined only for lists.
  • The law of eq?
    The primitive eq? takes two arguments.Each must be a nonnumeric atom.
  • The First Commandment
    Always ask null? as the first question in expressing any function.
  • The Second Commandment
    Use cons to build lists.
  • The Third Commandment
    When building a list, describe the first typical element, and then cons it onto the natural recursion.
  • The Fourth Commandment
    Always change at least one argument while recurring. It must be changed to be closer to the termination. The changing argument must be tested in the termination condition: when using cdr, test termination with null?.
  • The Fifth Commandment
    When building a value with +, always use 0 for the value of the terminating line, for adding 0 does not change the value of an addition.
    When building a value with x, always use 1 for the value of the terminating line, for multiplying by 1 does not change the value of multiplication.
    When building a value with cons, always consider () for the value of the terminating line.

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