branch: externals/trie
commit bc12ecbbefddaf2b56f7efd8beada5f33f251878
Author: Toby S. Cubitt <[email protected]>
Commit: Toby S. Cubitt <[email protected]>
Exploit lexical closures to allow byte-compilation of wrapped functions.
A number of functions are wrapped in a thin anonymous function before being
stored in the data structures. The wrappers were constructed as quoted
lambda
forms, so were not byte-compiled. Lexical closures allow the
wrapper-constructing functions to use unquoted lambdas, enabling
byte-compilation of the wrapped functions.
We fall back to old-style function wrapping if lexical binding unsupported.
---
trie.el | 54 ++++++++++++++++++++++++++++++++++++++----------------
1 file changed, 38 insertions(+), 16 deletions(-)
diff --git a/trie.el b/trie.el
index 50fb951..3fe434c 100644
--- a/trie.el
+++ b/trie.el
@@ -225,22 +225,44 @@
transform-for-print transform-from-read print-form)
-(defun trie--wrap-cmpfun (cmpfun)
- ;; wrap CMPFUN for use in a subtree
- `(lambda (a b)
- (setq a (trie--node-split a)
- b (trie--node-split b))
- (cond ((eq a trie--terminator)
- (if (eq b trie--terminator) nil t))
- ((eq b trie--terminator) nil)
- (t (,cmpfun a b)))))
-
-
-(defun trie--construct-equality-function (comparison-function)
- ;; create equality function from trie comparison function
- `(lambda (a b)
- (and (not (,comparison-function a b))
- (not (,comparison-function b a)))))
+(defmacro trie-lexical-binding-p ()
+ "Return non-nil if lexical binding is in effect, nil otherwise."
+ (let ((tempvar (make-symbol "x")))
+ `(let ((,tempvar nil)
+ (f (let ((,tempvar t)) (lambda () ,tempvar))))
+ (funcall f))))
+
+
+;; wrap CMPFUN for use in a subtree
+(if (trie-lexical-binding-p)
+ (defun trie--wrap-cmpfun (cmpfun)
+ (lambda (a b)
+ (setq a (trie--node-split a)
+ b (trie--node-split b))
+ (cond ((eq a trie--terminator)
+ (if (eq b trie--terminator) nil t))
+ ((eq b trie--terminator) nil)
+ (t (funcall cmpfun a b)))))
+ (defun trie--wrap-cmpfun (cmpfun)
+ `(lambda (a b)
+ (setq a (trie--node-split a)
+ b (trie--node-split b))
+ (cond ((eq a trie--terminator)
+ (if (eq b trie--terminator) nil t))
+ ((eq b trie--terminator) nil)
+ (t (,cmpfun a b))))))
+
+
+;; create equality function from trie comparison function
+(if (trie-lexical-binding-p)
+ (defun trie--construct-equality-function (comparison-function)
+ (lambda (a b)
+ (and (not (funcall comparison-function a b))
+ (not (funcall comparison-function b a)))))
+ (defun trie--construct-equality-function (comparison-function)
+ `(lambda (a b)
+ (and (not (,comparison-function a b))
+ (not (,comparison-function b a))))))
