cl-case-control

This package supports case-controlling in both "starndard" case-insensitive environment and "extended" case-sensitive environment.

Note that the ANSI Common Lisp is a case-sensitive language about symbol names.

(intern "AbC") ; => |AbC|
(symbol-name '|AbC|) ; => "AbC"

The term "case-insensitive" here is not for those "barrier" symbols but for "non-barrier" symbols on some extended CL implementations s.t. GNU CLISP.

(in-package :cs-common-lisp-user)
(intern "Abc") ; => Abc
(symbol-name 'Abc) ; => "Abc"
(in-package :common-lisp-user)
(symbol-name 'Abc) ; => "ABC"
(symbol-name 'ABC) ; => "ABC"

Those differences between standard "case-insensitive" mode and extended "case-sensitive" modes cause some troubles at coding.

This package is a helper for solving such problems.

APIs:

general-purpose predicates:

• [Function] string-designator-p

  Returns true if given object is a string designator, otherwise, returns false.

• [Function] lowercase-char-p and uppercase-char-p

  Returns true if given character is a lowercase (uppercase), otherwise, returns false.

  If the given object is not a character, these predicates signal an type error.

general-purpose converters:

• [Function] char-invertcase

  Returns case inverted character.

  If the given object is not a character, char-invertcase signals an type error.

• [Function] string-invertcase

  Returns case inverted string.

  If the given object is not a string designator, string-invertcase signals an type error.

  Note: string-invertcase accepts not only string but also string designator, but applying string-invertcase to symbol is depricated because an intuitive result is not necessarily obtained.

  e.g.

    (string-invertcase "aBc") ; => "AbC"
    (string-invertcase #\a) ; => "A"
    (string-invertcase :|aBc|) ; => "AbC"
    (string-invertcase NIL) ; => "nil"
    (string-invertcase Nil) ; => "nil"
    (string-invertcase nil) ; => "nil"
  

  Especially on GNU CLISP environment;

    (in-package :common-lisp-user)
    (symbol-name 'Abc) ; => "ABC"
    (casectl:string-invertcase 'Abc) ; => "abc"
    (in-package :cs-common-lisp-user)
    (symbol-name 'Abc) ; => "Abc"
    (casectl:string-invertcase 'Abc) ; => "Abc"
    (symbol-name :Abc) ; => "abc"
    (casectl:string-invertcase :Abc) ; => "abc"
  

  (casectl:char-invertcase and casectl:string-invertcase are just synonyms of exported functions of EXT package of CLISP, respectively.

  For CLISP's case sensitiveness, see CLISP Implementation Notes 11.5. Package Case-Sensitivity)

predicates for system/package case sensitiveness:

• [Function] case-sensitive-p

  Returns true if the system (compiler and/or interpreter) supports case-sensitiveness, otherwise, returns false.

• [Function] case-sensitive-package-p

  Returns true if the given package supports case-sensitiveness, otherwise, returns false.

  Current *package* is used when an package parameter is ommited.

utilities to unify codes in both case-sensitive environment and case-insensitive environment:

• [Function] adj-case

  Adjust string case. This function is a helper for making intern parameter.

  e.g.

    (in-package :a-case-insensitive-package)
    (setf (symbol-value (intern (adj-case "Foo"))) 1)
    (in-package :a-case-sensitive-package)
    (setf (symbol-value (intern (adj-case "Foo"))) 2)
  
    (in-package :another-package)
    ;; Is the :another-package case-sensitive or not?
    ;; No problem. Everything's fine.
    (list a-case-insensitive-package::Foo
          a-case-sensitive-package::Foo )
    ; => (1 2)
  

  adj-case can also spcify a package explicitly.

    (adj-case "Foo" :a-case-insensitive-package) ; => "FOO"
    (adj-case "Foo" :a-case-sensitive-package) ; => "Foo"
  

  WARNING: on GNU CLISP, specifying package explicitly in both adj-case and intern may cause error because of incomaptibility between cl:intern and cs-cl:intern.

    (in-package :a-case-insensitive-package)
    ;; no problem
    (intern (adj-case "Foo" :another-case-insensitive-package)
            :another-case-insensitive-package )
    ; => ANOTHER-CASE-INSENSITIVE-PACKAGE::FOO
  
    ;; maybe a bug
    (in-package :a-case-sensitive-package)
    (intern (adj-case "Bar" :a-case-insensitive-package)
            :a-case-insensitive-package )
    ; => a-case-insensitive-package::|bar|
  

• [Function] case-selective-intern

  A intern wrapper.

  e.g. (case-selective-intern "Foo")

  And also, you can specify intern-package optionally.

• [Macro] case-selective-defpackage

  A defpackage wrapper.

  e.g.

    (case-selective-defpackage :package-name
      (and (case-sensitive-p)
           (would-you-want-to-make-case-sensitive-package-p) )
      (:nicknames ...)
      ... )
  

History

• removed string-designator definition; use trivial-types package, instead.

License:

Under MIT license.