Predicates on Characters

The function characterp can be used to determine if an object is a Character object, See Specific Data Type Predicates. In the rest of these predicates the given character argument must be a Character object; if it is not, an error is signaled.

standardCharP character

Function

standardCharP returns t if character is a standard character and nil otherwise. See the Common Lisp specification for the definition of standard characters. For example

     standardCharP(L('a')) => t
     standardCharP(L(' ')) => t
     standardCharP(L('\n')) => t
     standardCharP(L('?')) => t
     standardCharP(codeChar(2)) => nil
     

alphaCharP character

Function

digitCharP character

Function

alphanumericp character

Function

alphaCharP returns t if character is an alphabet letter of either case and nil otherwise. digitCharP returns t if character is a 0-9 digit and nil otherwise. alphanumericp returns t if character is either a letter or digit and nil otherwise.

upperCaseP character

Function

lowerCaseP character

Function

upperCaseP returns t if character is an upper case letter and nil otherwise. lowerCaseP returns t if character is a lower case letter and nil otherwise.