Symbols

Purpose

Symbols are one of the most primitive types of expression Scheme can understand. A symbol is a series of one or more characters and numbers, though it must contain at least one character. (If it only contained numbers, it is a number, not a symbol.) A symbol can not contain any spaces.

Usage

When a symbol is evaluated, it returns that symbol.

A symbol can be created one of two ways. The user can use the function "quote", or the user can use an apostrophe, as will be shown below.

Examples

Symbols evaluate to themselves.

  ox --> 'sam
  sam
  ox --> (quote a)
  a
  ox --> 'a
  a

Return to Scheme Introduction

mrl