Matches if the object is a map (list, hash-table or array), and
binds values from ARGS to their corresponding elements of the map.
-ARGS can be a list elements of the form (KEY PAT) or elements
-of the form SYMBOL, which stands for ('SYMBOL SYMBOL)."
+ARGS can be a list elements of the form (KEY PAT), in which case
+KEY in an unquoted form.
+
+ARGS can also be a list of symbols, which stands for ('SYMBOL
+SYMBOL)."
`(and (pred map-p)
,@(map--make-pcase-bindings args)))
bound to the looked up value in MAP.
KEYS can also be a list of (KEY VARNAME) pairs, in which case
-KEY is not quoted.
+KEY is an unquoted form.
MAP can be a list, hash-table or array."
(declare (indent 2) (debug t))
`(pcase-let ((,(map--make-pcase-patterns keys) ,map))
,@body))
-(defmacro map--dispatch (spec &rest args)
- "Evaluate one of the forms specified by ARGS based on the type of MAP.
-
-SPEC can be a map or a list of the form (VAR MAP [RESULT]).
-ARGS should have the form [TYPE FORM]...
+(eval-when-compile
+ (defmacro map--dispatch (map-var &rest args)
+ "Evaluate one of the forms specified by ARGS based on the type of MAP.
The following keyword types are meaningful: `:list',
`:hash-table' and `:array'.
An error is thrown if MAP is neither a list, hash-table nor array.
-Return RESULT if non-nil or the result of evaluation of the
-form.
-
-\(fn (VAR MAP [RESULT]) &rest ARGS)"
- (declare (debug t) (indent 1))
- (unless (listp spec)
- (setq spec `(,spec ,spec)))
- (let ((map-var (car spec))
- (result-var (make-symbol "result")))
- `(let ((,map-var ,(cadr spec))
- ,result-var)
- (setq ,result-var
- (cond ((listp ,map-var) ,(plist-get args :list))
- ((hash-table-p ,map-var) ,(plist-get args :hash-table))
- ((arrayp ,map-var) ,(plist-get args :array))
- (t (error "Unsupported map: %s" ,map-var))))
- ,@(when (cddr spec)
- `((setq ,result-var ,@(cddr spec))))
- ,result-var)))
+Return RESULT if non-nil or the result of evaluation of the form."
+ (declare (debug t) (indent 1))
+ `(cond ((listp ,map-var) ,(plist-get args :list))
+ ((hash-table-p ,map-var) ,(plist-get args :hash-table))
+ ((arrayp ,map-var) ,(plist-get args :array))
+ (t (error "Unsupported map: %s" ,map-var)))))
(defun map-elt (map key &optional default)
"Perform a lookup in MAP of KEY and return its associated value.
If KEY is not found, return DEFAULT which defaults to nil.
-If MAP is a list, `equal' is used to lookup KEY.
+If MAP is a list, `eql' is used to lookup KEY.
MAP can be a list, hash-table or array."
+ (declare
+ (gv-expander
+ (lambda (do)
+ (gv-letplace (mgetter msetter) `(gv-delay-error ,map)
+ (macroexp-let2* nil
+ ;; Eval them once and for all in the right order.
+ ((key key) (default default))
+ `(if (listp ,mgetter)
+ ;; Special case the alist case, since it can't be handled by the
+ ;; map--put function.
+ ,(gv-get `(alist-get ,key (gv-synthetic-place
+ ,mgetter ,msetter)
+ ,default)
+ do)
+ ,(funcall do `(map-elt ,mgetter ,key ,default)
+ (lambda (v) `(map--put ,mgetter ,key ,v)))))))))
(map--dispatch map
- :list (map--elt-list map key default)
+ :list (alist-get key map default)
:hash-table (gethash key map default)
- :array (map--elt-array map key default)))
+ :array (if (and (>= key 0) (< key (seq-length map)))
+ (seq-elt map key)
+ default)))
(defmacro map-put (map key value)
"In MAP, associate KEY with VALUE and return MAP.
with VALUE.
MAP can be a list, hash-table or array."
- (declare (debug t))
- (let ((symbol (symbolp map)))
+ (macroexp-let2 nil map map
`(progn
- (map--dispatch (m ,map m)
- :list (if ,symbol
- (setq ,map (cons (cons ,key ,value) m))
- (error "Literal lists are not allowed, %s must be a symbol" ',map))
- :hash-table (puthash ,key ,value m)
- :array (aset m ,key ,value)))))
+ (setf (map-elt ,map ,key) ,value)
+ ,map)))
(defmacro map-delete (map key)
"In MAP, delete the key KEY if present and return MAP.
MAP can be a list, hash-table or array."
(declare (debug t))
- (let ((symbol (symbolp map)))
- `(progn
- (map--dispatch (m ,map m)
- :list (if ,symbol
- (setq ,map (map--delete-alist m ,key))
- (error "Literal lists are not allowed, %s must be a symbol" ',map))
- :hash-table (remhash ,key m)
- :array (map--delete-array m ,key)))))
+ (gv-letplace (mgetter msetter) `(gv-delay-error ,map)
+ (macroexp-let2 nil key key
+ `(if (not (listp ,mgetter))
+ (map--delete ,mgetter ,key)
+ ;; The alist case is special, since it can't be handled by the
+ ;; map--delete function.
+ (setf (alist-get ,key (gv-synthetic-place ,mgetter ,msetter)
+ nil t)
+ nil)
+ ,mgetter))))
(defun map-nested-elt (map keys &optional default)
"Traverse MAP using KEYS and return the looked up value or DEFAULT if nil.
map))
(defun map-filter (pred map)
- "Return an alist of the key/val pairs for which (PRED key val) is non-nil in MAP.
+ "Return an alist of key/val pairs for which (PRED key val) is non-nil in MAP.
MAP can be a list, hash-table or array."
(delq nil (map-apply (lambda (key val)
(let (result)
(while maps
(map-apply (lambda (key value)
- (map-put result key value))
+ (setf (map-elt result key) value))
(pop maps)))
(map-into result type)))
(pcase type
(`list (map-pairs map))
(`hash-table (map--into-hash-table map))
- (t (error "Not a map type name: %S" type))))
+ (_ (error "Not a map type name: %S" type))))
+
+(defun map--put (map key v)
+ (map--dispatch map
+ :list (let ((p (assoc key map)))
+ (if p (setcdr p v)
+ (error "No place to change the mapping for %S" key)))
+ :hash-table (puthash key v map)
+ :array (aset map key v)))
(defun map--apply-alist (function map)
"Private function used to apply FUNCTION over MAP, MAP being an alist."
(cdr pair)))
map))
+(defun map--delete (map key)
+ (map--dispatch map
+ :list (error "No place to remove the mapping for %S" key)
+ :hash-table (remhash key map)
+ :array (and (>= key 0)
+ (<= key (seq-length map))
+ (aset map key nil)))
+ map)
+
(defun map--apply-hash-table (function map)
"Private function used to apply FUNCTION over MAP, MAP being a hash-table."
(let (result)
(setq index (1+ index))))
map)))
-(defun map--elt-list (map key &optional default)
- "Lookup, in the list MAP, the value associated with KEY and return it.
-If KEY is not found, return DEFAULT which defaults to nil."
- (let ((pair (assoc key map)))
- (if pair
- (cdr pair)
- default)))
-
-(defun map--elt-array (map key &optional default)
- "Return the element of the array MAP at the index KEY.
-If KEY is not found, return DEFAULT which defaults to nil."
- (let ((len (seq-length map)))
- (or (and (>= key 0)
- (<= key len)
- (seq-elt map key))
- default)))
-
-(defun map--delete-alist (map key)
- "Return MAP with KEY removed."
- (seq-remove (lambda (pair)
- (equal key (car pair)))
- map))
-
-(defun map--delete-array (map key)
- "Set nil in the array MAP at the index KEY if present and return MAP."
- (let ((len (seq-length map)))
- (and (>= key 0)
- (<= key len)
- (aset map key nil)))
- map)
-
(defun map--into-hash-table (map)
"Convert MAP into a hash-table."
(let ((ht (make-hash-table :size (map-length map)
:test 'equal)))
(map-apply (lambda (key value)
- (map-put ht key value))
+ (setf (map-elt ht key) value))
map)
ht))