-(defpsmacro let (bindings &body body)
- (flet ((add-renamed-vars (bindings predicate)
- (mapcar (lambda (x) (append x (list (ps-gensym (car x)))))
- (remove-if predicate bindings :key #'car)))
- (var (x) (first x))
- (val (x) (second x))
- (renamed (x) (third x)))
- (let* ((normalized-bindings (mapcar (lambda (x) (if (symbolp x) `(,x nil) x)) bindings))
- (lexical-bindings (add-renamed-vars normalized-bindings #'ps-special-variable-p))
- (dynamic-bindings (add-renamed-vars normalized-bindings (complement #'ps-special-variable-p)))
- (renamed-body `(symbol-macrolet ,(mapcar (lambda (x) (list (var x) (renamed x)))
- lexical-bindings)
- ,@body)))
- `(progn
- ,@(mapcar (lambda (x) `(var ,(renamed x) ,(val x))) lexical-bindings)
- ,(if dynamic-bindings
- `(progn ,@(mapcar (lambda (x) `(var ,(renamed x))) dynamic-bindings)
- (try (progn (setf ,@(loop for x in dynamic-bindings append
- `(,(renamed x) ,(var x)
- ,(var x) ,(val x))))
- ,renamed-body)
- (:finally
- (setf ,@(mapcan (lambda (x) `(,(var x) ,(renamed x))) dynamic-bindings)))))
- renamed-body)))))
+(define-ps-special-form let (bindings &body body)
+ (let* (lexical-bindings-introduced-here
+ (normalized-bindings (mapcar (lambda (x) (if (symbolp x) `(,x nil) x)) bindings))
+ (free-variables-in-binding-value-expressions (mapcan (lambda (x) (flatten (cadr x)))
+ normalized-bindings)))
+ (flet ((maybe-rename-lexical-var (x)
+ (if (or (member x *vars-bound-in-enclosing-lexical-scopes*)
+ (member x free-variables-in-binding-value-expressions))
+ (ps-gensym x)
+ (progn (push x lexical-bindings-introduced-here) nil)))
+ (rename (x) (first x))
+ (var (x) (second x))
+ (val (x) (third x)))
+ (let* ((lexical-bindings (loop for x in normalized-bindings
+ unless (ps-special-variable-p (car x))
+ collect (cons (maybe-rename-lexical-var (car x)) x)))
+ (dynamic-bindings (loop for x in normalized-bindings
+ when (ps-special-variable-p (car x))
+ collect (cons (ps-gensym (format nil "~A_~A" (car x) 'tmp-stack)) x)))
+ (renamed-body `(symbol-macrolet ,(loop for x in lexical-bindings
+ when (rename x) collect
+ `(,(var x) ,(rename x)))
+ ,@body))
+ (*vars-bound-in-enclosing-lexical-scopes* (append lexical-bindings-introduced-here
+ *vars-bound-in-enclosing-lexical-scopes*)))
+ (compile-parenscript-form
+ `(progn
+ ,@(mapcar (lambda (x) `(var ,(or (rename x) (var x)) ,(val x))) lexical-bindings)
+ ,(if dynamic-bindings
+ `(progn ,@(mapcar (lambda (x) `(var ,(rename x))) dynamic-bindings)
+ (try (progn (setf ,@(loop for x in dynamic-bindings append
+ `(,(rename x) ,(var x)
+ ,(var x) ,(val x))))
+ ,renamed-body)
+ (:finally
+ (setf ,@(mapcan (lambda (x) `(,(var x) ,(rename x))) dynamic-bindings)))))
+ renamed-body))
+ :expecting expecting)))))