refactor using map-let, reformat

grid.el

@@ -45,12 +45,13 @@
 ;;; Code:
 
 (require 'subr-x)
+(require 'map)
 
 (defvar grid-margin 1)
 
-(defun grid-content-empty-p (box)
+(defun grid-content-not-empty-p (box)
   "Non-nil if content of BOX is empty."
-  (string-empty-p (plist-get box :content)))
+  (not (string-empty-p (plist-get box :content))))
 
 (defvar grid-overline '(:overline t) "Overline face.")
 
@@ -71,7 +72,7 @@
   (if (stringp width)
       (floor
        (* (window-width)
-	  (/ (string-to-number width) 100.0)))
+          (/ (string-to-number width) 100.0)))
     width))
 
 (defun grid--reformat-content (content width align)
@@ -87,71 +88,82 @@
 
 (defun grid--longest-line-length (string)
   "Get the length of the longest line in STRING."
-  (let ((lines (split-string string "\n")))
-    (thread-last lines
-		 (seq-map #'length)
-		 (seq-max))))
+  (thread-last (split-string string "\n")
+    (seq-map #'length)
+    (seq-max)))
+
+(defalias #'grid--merge-plists
+  (apply-partially #'map-merge-with 'plist (lambda (_ x) x))
+  "Merge plists, the last one takes precedence.")
+
+(defun grid--fill-box (box)
+  "Calculate and fill in the missing fields in BOX."
+  ;; `map-let' doesn't provide access to keywords directly
+  (map-let ((:content content)
+            (:align align)
+            (:padding padding)
+            (:width width))
+      box
+    (let* ((padding (* (or padding 0) 2))
+           (width-raw (or width (grid--longest-line-length content)))
+           (width (- (grid--normalize-width width-raw) padding))
+           (content (grid--reformat-content content width align))
+           (box-extra (list :width width
+                            :content content
+                            :length (length content))))
+      (when (< width 0)
+        (user-error "Horizonal padding %s must be less than width %s"
+                    padding width-raw))
+      (grid--merge-plists box box-extra))))
 
 (defun grid--normalize-box (box)
-  "Return a normalized copy of BOX."
-  (let* ((box (pcase box
-		((pred plistp) (copy-tree box))
-		((pred stringp) (list :content box))))
-	 (content (plist-get box :content))
-	 (align (plist-get box :align))
-	 (padding (* (or (plist-get box :padding) 0) 2))
-	 (width-raw
-	  (or
-	   (plist-get box :width)
-	   (let ((width (grid--longest-line-length content)))
-	     (setq box (plist-put box :width width))
-	     width)))
-	 (width (- (grid--normalize-width width-raw) padding)))
-    (when (< width 0)
-      (user-error "Horizonal padding must be less than width"))
-    (setq box (plist-put box :width width))
-    (setq box (plist-put box :content (grid--reformat-content content width align)))
-    (setq box (plist-put box :length (length (plist-get box :content))))
-    box))
+  "Normalize BOX to plist."
+  (cond
+   ((plistp box) (copy-tree box))
+   ((stringp box) (list :content box))))
+
+(defun grid--format-box (box)
+  "Insert BOX in the current buffer."
+  (map-let ((:content content)
+            (:padding padding)
+            (:width width)
+            (:border border)
+            (:length length))
+      box
+    (let* ((content-len (length content))
+           (line-len (min width content-len))
+           (padding (make-string (or padding 0) ? ))
+           (fmt (format "%s%% -%ds%s" padding width padding))
+           (line (format fmt (substring content 0 line-len)))
+           (new-content (substring content
+                                   (min content-len (1+ width))))
+           (border-face (cond
+                         ;; first line?
+                         ((= length content-len) grid-overline)
+                         ;; in body?
+	                     ((/= content-len 0) grid-vertical-borders)
+	                     ;; last line?
+	                     ((and (zerop content-len)
+                               (string-empty-p new-content)) grid-underline))))
+      (when (and border border-face)
+        (grid--apply-face line border-face))
+      (setq box (plist-put box :content new-content))
+      line)))
 
 (defun grid--insert-row (row)
   "Insert ROW in the current buffer."
-  (while (not (seq-every-p #'grid-content-empty-p row))
-    (mapc #'grid--insert-box row)
-    (delete-char (* grid-margin -1))
-    (insert ?\n))
+  (let ((normalized-row (seq-map (lambda (box)
+                                   (grid--fill-box (grid--normalize-box box)))
+                                 row)))
+    (while (seq-some #'grid-content-not-empty-p normalized-row)
+      (mapc (lambda (box)
+              (insert (grid--format-box box))
+              (insert-char ?  grid-margin))
+            normalized-row)
+      (delete-char (* grid-margin -1))
+      (insert ?\n)))
   (insert ?\n))
 
-(defun grid--insert-box (box)
-  "Insert BOX in the current buffer."
-  (let* ((content (plist-get box :content))
-	 (content-len (length content))
-	 (padding-len (or (plist-get box :padding) 0))
-	 (padding (make-string padding-len ? ))
-	 (width (plist-get box :width))
-	 (line-len (min width content-len))
-	 (line
-	  (concat
-	   padding
-	   (format (format "%% -%ds" width)
-		   (substring content 0 line-len))
-	   padding))
-	 (donep (string-empty-p content))
-	 (new-content (substring content
-				 (min content-len (1+ width)))))
-    (when (plist-get box :border)
-      (grid--apply-face line
-	(append
-	 ;; first line?
-	 (and (= (plist-get box :length) content-len) grid-overline)
-	 ;; in body?
-	 (and (/= content-len 0) grid-vertical-borders)
-	 ;; last line?
-	 (and (not donep) (string-empty-p new-content) grid-underline))))
-    (insert line)
-    (insert-char ?  grid-margin)
-    (setq box (plist-put box :content new-content))))
-
 (defsubst grid--trim-line ()
   (beginning-of-line)
   (delete-horizontal-space)
@@ -178,21 +190,22 @@ ALIGN values: `left' (default), `right', `center', `full'."
   (interactive "P")
   (let (space)
     (while (not (eobp))
-      (if align (grid--trim-line)
-	(end-of-line))
+      (if align
+          (grid--trim-line)
+	    (end-of-line))
       (setq space (- fill-column (current-column)))
       (if (>= space 0)
-	  (grid--align-line align space)
-	(let ((beg (line-beginning-position)))
-	  (fill-region beg (line-end-position) align)
-	  (goto-char beg)
-	  (grid--trim-line)
-	  (setq space (- fill-column (current-column)))
-	  (when (< space 0)
-	    (forward-char space)
-	    (insert ?\n)
-	    (setq space (+ fill-column space)))
-	  (grid--align-line align space)))
+	      (grid--align-line align space)
+	    (let ((beg (line-beginning-position)))
+	      (fill-region beg (line-end-position) align)
+	      (goto-char beg)
+	      (grid--trim-line)
+	      (setq space (- fill-column (current-column)))
+	      (when (< space 0)
+	        (forward-char space)
+	        (insert ?\n)
+	        (setq space (+ fill-column space)))
+	      (grid--align-line align space)))
       (forward-line 1))))
 
 ;;; API
@@ -207,7 +220,7 @@ ALIGN values: `left' (default), `right', `center', `full'."
 
 (defun grid-insert-row (row)
   "Insert ROW in the current buffer."
-  (grid--insert-row (mapcar #'grid--normalize-box row)))
+  (grid--insert-row row))
 
 (defun grid-insert-column (column)
   "Insert COLUMN in the current buffer."