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Diffstat (limited to 'third_party/lisp/alexandria/symbols.lisp')
-rw-r--r-- | third_party/lisp/alexandria/symbols.lisp | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/third_party/lisp/alexandria/symbols.lisp b/third_party/lisp/alexandria/symbols.lisp new file mode 100644 index 000000000000..5733d3e1cc50 --- /dev/null +++ b/third_party/lisp/alexandria/symbols.lisp @@ -0,0 +1,65 @@ +(in-package :alexandria) + +(declaim (inline ensure-symbol)) +(defun ensure-symbol (name &optional (package *package*)) + "Returns a symbol with name designated by NAME, accessible in package +designated by PACKAGE. If symbol is not already accessible in PACKAGE, it is +interned there. Returns a secondary value reflecting the status of the symbol +in the package, which matches the secondary return value of INTERN. + +Example: + + (ensure-symbol :cons :cl) => cl:cons, :external +" + (intern (string name) package)) + +(defun maybe-intern (name package) + (values + (if package + (intern name (if (eq t package) *package* package)) + (make-symbol name)))) + +(declaim (inline format-symbol)) +(defun format-symbol (package control &rest arguments) + "Constructs a string by applying ARGUMENTS to string designator CONTROL as +if by FORMAT within WITH-STANDARD-IO-SYNTAX, and then creates a symbol named +by that string. + +If PACKAGE is NIL, returns an uninterned symbol, if package is T, returns a +symbol interned in the current package, and otherwise returns a symbol +interned in the package designated by PACKAGE." + (maybe-intern (with-standard-io-syntax + (apply #'format nil (string control) arguments)) + package)) + +(defun make-keyword (name) + "Interns the string designated by NAME in the KEYWORD package." + (intern (string name) :keyword)) + +(defun make-gensym (name) + "If NAME is a non-negative integer, calls GENSYM using it. Otherwise NAME +must be a string designator, in which case calls GENSYM using the designated +string as the argument." + (gensym (if (typep name '(integer 0)) + name + (string name)))) + +(defun make-gensym-list (length &optional (x "G")) + "Returns a list of LENGTH gensyms, each generated as if with a call to MAKE-GENSYM, +using the second (optional, defaulting to \"G\") argument." + (let ((g (if (typep x '(integer 0)) x (string x)))) + (loop repeat length + collect (gensym g)))) + +(defun symbolicate (&rest things) + "Concatenate together the names of some strings and symbols, +producing a symbol in the current package." + (let* ((length (reduce #'+ things + :key (lambda (x) (length (string x))))) + (name (make-array length :element-type 'character))) + (let ((index 0)) + (dolist (thing things (values (intern name))) + (let* ((x (string thing)) + (len (length x))) + (replace name x :start1 index) + (incf index len)))))) |