diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 20 |
1 files changed, 19 insertions, 1 deletions
@@ -54483,7 +54483,7 @@ uses to form the name of the new symbol. .coNP Function @ make-package .synb -.mets (make-package << name ) +.mets (make-package < name <> [ weak ]) .syne .desc The @@ -54499,6 +54499,24 @@ should be performed with the macro rather than by direct use of .codn make-package . +If the +.meta weak +parameter is given an argument which is a Boolean true, then the resulting +package holds symbols weakly, from a garbage collection point of view. If the +only reference to a symbol is that which occurs inside the weak package, then +that symbol may be removed from the package and reclaimed by the garbage +collector. + +Note: weak packages address the following problem. The application creates a +package for the purpose of reading Lisp data. Symbols occurring in that data +therefore are interned into the package. Subsequently, the application retains +references to some of the symbols, discarding the others. If the package isn't +weak, then because the application is retaining some of the symbols, and those +symbols hold a reference to the package, and the package holds a reference to +all symbols that were interned in it, all of the symbols are retained. If a +weak package is used, then the uninterested symbols are eligible for garbage +collection. + .coNP Function @ delete-package .synb .mets (delete-package << package ) |