intern

(intern string [package])

Returns the symbol named by string (no case folding) in package -- the current package by default (Common Lisp's *package* semantics): an accessible symbol keeps its home spelling, and an unknown name becomes a symbol of the package and is recorded in its member table, so a later find-symbol answers it and do-symbols enumerates it. rontolisp symbols compare by name, so the result is eq to any symbol with the same spelling, including quoted literals -- which is what lets a macro-time (intern (concatenate ...)) under (in-package p) name the same function as a literal defun in that file. A string that already carries a package qualifier ("LIB:WIDGET") names that symbol rather than a fresh symbol of the whole string, so a canonical spelling produced at run time — the type name type-of reads off a class, say — round-trips. (intern name :keyword) builds a keyword, and the package argument accepts any package designator — a keyword, a string, or a package value held in a variable; a package that does not exist signals a package-error whose package-error-package is the designator, and creates nothing. Like find-symbol, a second value reports the accessibility status the name had before the intern (nil for a fresh name, as in Common Lisp); the function object #'intern takes the same optional package and answers the same two values. The names "T" and "NIL" answer t and nil themselves on every backend -- those two are singletons, not symbols of that spelling.

Deviation from Common Lisp: on the compiled backends a package-qualified intern into a read/compile-time package (a built-in, or a defpackage of the compiled program) yields the single-colon external spelling, so an unexported symbol interned this way is not eq to its double-colon literal (calling it as a function still works). A name the package already reaches answers that symbol instead, as find-symbol does: an import, a re-export, a symbol inherited through :use (a standard name through cl included), or a member its defpackage records (:shadow, :intern). A package the program creates with make-package keeps its member table on every backend, and an intern into it records the member exactly as the interpreter does.