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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.