Info Catalog eintr: Prevent confusion eintr: let eintr: Sample let Expression

eintr: Parts of let Expression

 
 3.6.1 The Parts of a ‘let’ Expression
 -------------------------------------
 
 A ‘let’ expression is a list of three parts.  The first part is the
 symbol ‘let’.  The second part is a list, called a “varlist”, each
 element of which is either a symbol by itself or a two-element list, the
 first element of which is a symbol.  The third part of the ‘let’
 expression is the body of the ‘let’.  The body usually consists of one
 or more lists.
 
    A template for a ‘let’ expression looks like this:
 
      (let VARLIST BODY...)
 
 The symbols in the varlist are the variables that are given initial
 values by the ‘let’ special form.  Symbols by themselves are given the
 initial value of ‘nil’; and each symbol that is the first element of a
 two-element list is bound to the value that is returned when the Lisp
 interpreter evaluates the second element.
 
    Thus, a varlist might look like this: ‘(thread (needles 3))’.  In
 this case, in a ‘let’ expression, Emacs binds the symbol ‘thread’ to an
 initial value of ‘nil’, and binds the symbol ‘needles’ to an initial
 value of 3.
 
    When you write a ‘let’ expression, what you do is put the appropriate
 expressions in the slots of the ‘let’ expression template.
 
    If the varlist is composed of two-element lists, as is often the
 case, the template for the ‘let’ expression looks like this:
 
      (let ((VARIABLE VALUE)
            (VARIABLE VALUE)
            ...)
        BODY...)
 

Info Catalog eintr: Prevent confusion eintr: let eintr: Sample let Expression