Info Catalog elisp: Variables with Restricted Values elisp: Variables

elisp: Generalized Variables

 
 11.15 Generalized Variables
 ===========================
 
 A “generalized variable” or “place form” is one of the many places in
 Lisp memory where values can be stored.  The simplest place form is a
 regular Lisp variable.  But the CARs and CDRs of lists, elements of
 arrays, properties of symbols, and many other locations are also places
 where Lisp values are stored.
 
    Generalized variables are analogous to lvalues in the C language,
 where ‘x = a[i]’ gets an element from an array and ‘a[i] = x’ stores an
 element using the same notation.  Just as certain forms like ‘a[i]’ can
 be lvalues in C, there is a set of forms that can be generalized
 variables in Lisp.
 

Menu

 
· Setting Generalized Variables   The ‘setf’ macro.
· Adding Generalized Variables    Defining new ‘setf’ forms.
 

Info Catalog elisp: Variables with Restricted Values elisp: Variables