Add new function map-do

[gnu-emacs] / lisp / emacs-lisp / map.el

diff --git a/lisp/emacs-lisp/map.el b/lisp/emacs-lisp/map.el
index 85f6bcaa73cfb2211da33772a2ceca04e0ebac51..7c4afb91304135056d6f4c38235e66a862e1b010 100644 (file)
--- a/lisp/emacs-lisp/map.el
+++ b/lisp/emacs-lisp/map.el
@@ -1,10 +1,10 @@
 ;;; map.el --- Map manipulation functions  -*- lexical-binding: t; -*-
 
 ;;; map.el --- Map manipulation functions  -*- lexical-binding: t; -*-
 

-;; Copyright (C) 2015 Free Software Foundation, Inc.
+;; Copyright (C) 2015-2016 Free Software Foundation, Inc.

 
 ;; Author: Nicolas Petton <nicolas@petton.fr>
 ;; Keywords: convenience, map, hash-table, alist, array
 
 ;; Author: Nicolas Petton <nicolas@petton.fr>
 ;; Keywords: convenience, map, hash-table, alist, array

-;; Version: 1.0
+;; Version: 1.1

 ;; Package: map
 
 ;; Maintainer: emacs-devel@gnu.org
 ;; Package: map
 
 ;; Maintainer: emacs-devel@gnu.org


@@ -43,15 +43,24 @@
 ;;; Code:
 
 (require 'seq)
 ;;; Code:
 
 (require 'seq)

+(eval-when-compile (require 'cl-lib))

 
 (pcase-defmacro map (&rest args)
 
 (pcase-defmacro map (&rest args)

-  "pcase pattern matching map elements.
-Matches if the object is a map (list, hash-table or array), and
-binds values from ARGS to their corresponding elements of the map.
+  "Build a `pcase' pattern matching map elements.

 
 

-ARGS can be a list elements of the form (KEY PAT) or elements
-of the form SYMBOL, which stands for ('SYMBOL SYMBOL)."
-  `(and (pred map-p)
+ARGS is a list of elements to be matched in the map.
+
+Each element of ARGS can be of the form (KEY PAT), in which case KEY is
+evaluated and searched for in the map.  The match fails if for any KEY
+found in the map, the corresponding PAT doesn't match the value
+associated to the KEY.
+
+Each element can also be a SYMBOL, which is an abbreviation of a (KEY
+PAT) tuple of the form (\\='SYMBOL SYMBOL).
+
+Keys in ARGS not found in the map are ignored, and the match doesn't
+fail."
+  `(and (pred mapp)

         ,@(map--make-pcase-bindings args)))
 
 (defmacro map-let (keys map &rest body)
         ,@(map--make-pcase-bindings args)))
 
 (defmacro map-let (keys map &rest body)


@@ -61,93 +70,87 @@ KEYS can be a list of symbols, in which case each element will be
 bound to the looked up value in MAP.
 
 KEYS can also be a list of (KEY VARNAME) pairs, in which case
 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))
 
 
 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.
 
 
 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)
 
 (defun map-elt (map key &optional default)

-  "Perform a lookup in MAP of KEY and return its associated value.
+  "Lookup KEY in MAP and return its associated value.

 If KEY is not found, return DEFAULT which defaults to nil.
 
 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."
 
 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
   (map--dispatch map

-    :list (map--elt-list map key default)
+    :list (alist-get key map default)

     :hash-table (gethash 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)
 
 (defmacro map-put (map key value)

-  "In MAP, associate KEY with VALUE and return MAP.
+  "Associate KEY with VALUE in MAP and return VALUE.

 If KEY is already present in MAP, replace the associated value
 with VALUE.
 
 MAP can be a list, hash-table or array."
 If KEY is already present in MAP, replace the associated value
 with VALUE.
 
 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 (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)))))
-
-(defmacro map-delete (map key)
-  "In MAP, delete the key KEY if present and return MAP.
-If MAP is an array, store nil at the index KEY.
+  `(setf (map-elt ,map ,key) ,value))
+
+(defun map-delete (map key)
+  "Delete KEY from MAP and return MAP.
+No error is signaled if KEY is not a key of MAP.  If MAP is an
+array, store nil at the index KEY.

 
 MAP can be a list, hash-table or array."
 
 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)))))
+  (map--dispatch map
+    :list (setf (alist-get key map nil t) nil)
+    :hash-table (remhash key map)
+    :array (and (>= key 0)
+                (<= key (seq-length map))
+                (aset map key nil)))
+  map)

 
 (defun map-nested-elt (map keys &optional default)
   "Traverse MAP using KEYS and return the looked up value or DEFAULT if nil.
 
 Map can be a nested map composed of alists, hash-tables and arrays."
   (or (seq-reduce (lambda (acc key)
 
 (defun map-nested-elt (map keys &optional default)
   "Traverse MAP using KEYS and return the looked up value or DEFAULT if nil.
 
 Map can be a nested map composed of alists, hash-tables and arrays."
   (or (seq-reduce (lambda (acc key)

-                    (when (map-p acc)
+                    (when (mapp acc)

                       (map-elt acc key)))
                   keys
                   map)
                       (map-elt acc key)))
                   keys
                   map)


@@ -198,6 +201,16 @@ MAP can be a list, hash-table or array."
            function
            map))
 
            function
            map))
 

+(defun map-do (function map)
+  "Apply FUNCTION to each element of MAP and return nil.
+FUNCTION.is called with two arguments, the key and the value."
+  (funcall (map--dispatch map
+             :list #'map--do-alist
+             :hash-table #'maphash
+             :array #'map--do-array)
+           function
+           map))
+

 (defun map-keys-apply (function map)
   "Return the result of applying FUNCTION to each key of MAP.
 
 (defun map-keys-apply (function map)
   "Return the result of applying FUNCTION to each key of MAP.
 


@@ -215,7 +228,7 @@ MAP can be a list, hash-table or array."
              map))
 
 (defun map-filter (pred map)
              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)
 
 MAP can be a list, hash-table or array."
   (delq nil (map-apply (lambda (key val)


@@ -231,14 +244,14 @@ MAP can be a list, hash-table or array."
   (map-filter (lambda (key val) (not (funcall pred key val)))
               map))
 
   (map-filter (lambda (key val) (not (funcall pred key val)))
               map))
 

-(defun map-p (map)
+(defun mapp (map)

   "Return non-nil if MAP is a map (list, hash-table or array)."
   (or (listp map)
       (hash-table-p map)
       (arrayp map)))
 
 (defun map-empty-p (map)
   "Return non-nil if MAP is a map (list, hash-table or array)."
   (or (listp map)
       (hash-table-p map)
       (arrayp map)))
 
 (defun map-empty-p (map)

-  "Return non-nil is MAP is empty.
+  "Return non-nil if MAP is empty.

 
 MAP can be a list, hash-table or array."
   (map--dispatch map
 
 MAP can be a list, hash-table or array."
   (map--dispatch map


@@ -246,21 +259,22 @@ MAP can be a list, hash-table or array."
     :array (seq-empty-p map)
     :hash-table (zerop (hash-table-count map))))
 
     :array (seq-empty-p map)
     :hash-table (zerop (hash-table-count map))))
 

-(defun map-contains-key-p (map key &optional testfn)
-  "Return non-nil if MAP contain the key KEY, nil otherwise.
+(defun map-contains-key (map key &optional testfn)
+  "Return non-nil if MAP contain KEY, nil otherwise.

 Equality is defined by TESTFN if non-nil or by `equal' if nil.
 
 MAP can be a list, hash-table or array."
 Equality is defined by TESTFN if non-nil or by `equal' if nil.
 
 MAP can be a list, hash-table or array."

-  (seq-contains-p (map-keys map) key testfn))
+  (seq-contains (map-keys map) key testfn))

 
 

-(defun map-some-p (pred map)
-  "Return a key/value pair for which (PRED key val) is non-nil in MAP.
+(defun map-some (pred map)
+  "Return a non-nil if (PRED key val) is non-nil for any key/value pair in MAP.

 
 MAP can be a list, hash-table or array."
   (catch 'map--break
     (map-apply (lambda (key value)
 
 MAP can be a list, hash-table or array."
   (catch 'map--break
     (map-apply (lambda (key value)

-                 (when (funcall pred key value)
-                   (throw 'map--break (cons key value))))
+                 (let ((result (funcall pred key value)))
+                   (when result
+                     (throw 'map--break result))))

                map)
     nil))
 
                map)
     nil))
 


@@ -270,21 +284,42 @@ MAP can be a list, hash-table or array."
 MAP can be a list, hash-table or array."
   (catch 'map--break
     (map-apply (lambda (key value)
 MAP can be a list, hash-table or array."
   (catch 'map--break
     (map-apply (lambda (key value)

-                 (or (funcall pred key value)
-                     (throw 'map--break nil)))
-               map)
+              (or (funcall pred key value)
+                  (throw 'map--break nil)))
+            map)

     t))
 
 (defun map-merge (type &rest maps)
     t))
 
 (defun map-merge (type &rest maps)

-  "Merge into a map of type TYPE all the key/value pairs in the maps MAPS.
+  "Merge into a map of type TYPE all the key/value pairs in MAPS.

 
 MAP can be a list, hash-table or array."
 
 MAP can be a list, hash-table or array."

-  (let (result)
+  (let ((result (map-into (pop maps) type)))

     (while maps
     (while maps

+      ;; FIXME: When `type' is `list', we get an O(N^2) behavior.
+      ;; For small tables, this is fine, but for large tables, we
+      ;; should probably use a hash-table internally which we convert
+      ;; to an alist in the end.

       (map-apply (lambda (key value)
       (map-apply (lambda (key value)

-                   (map-put result key value))
+                   (setf (map-elt result key) value))

                  (pop maps)))
                  (pop maps)))

-    (map-into result type)))
+    result))
+
+(defun map-merge-with (type function &rest maps)
+  "Merge into a map of type TYPE all the key/value pairs in MAPS.
+When two maps contain the same key, call FUNCTION on the two
+values and use the value returned by it.
+MAP can be a list, hash-table or array."
+  (let ((result (map-into (pop maps) type))
+        (not-found (cons nil nil)))
+    (while maps
+      (map-apply (lambda (key value)
+                   (cl-callf (lambda (old)
+                               (if (eq old not-found)
+                                   value
+                                 (funcall function old value)))
+                       (map-elt result key not-found)))
+                 (pop maps)))
+    result))

 
 (defun map-into (map type)
   "Convert the map MAP into a map of type TYPE.
 
 (defun map-into (map type)
   "Convert the map MAP into a map of type TYPE.


@@ -294,7 +329,15 @@ MAP can be a list, hash-table or array."
   (pcase type
     (`list (map-pairs map))
     (`hash-table (map--into-hash-table map))
   (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."
 
 (defun map--apply-alist (function map)
   "Private function used to apply FUNCTION over MAP, MAP being an alist."


@@ -321,43 +364,26 @@ MAP can be a list, hash-table or array."
                  (setq index (1+ index))))
              map)))
 
                  (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--do-alist (function alist)
+  "Private function used to iterate over ALIST using FUNCTION."
+  (seq-do (lambda (pair)
+            (funcall function
+                     (car pair)
+                     (cdr pair)))
+          alist))

 
 

-(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--do-array (function array)
+  "Private function usde to iterate over ARRAY using FUNCTION."
+  (seq-do-indexed (lambda (elt index)
+                     (funcall function index elt))
+                   array))

 
 (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)
 
 (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))
 
                map)
     ht))