org-gfm-footnote-section: Cosmetics

- It is redundant to use `function' around `lambda'.
- It is semantically better to use `and' if the returned value
  matters.  `when' should be used if we only care about the
  side-effects.

ox-gfm.el

@@ -1,4 +1,4 @@
-;;; ox-gfm.el --- Github Flavored Markdown Back-End for Org Export Engine
+;;; ox-gfm.el --- Github Flavored Markdown Back-End for Org Export Engine -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 2014-2017 Lars Tveito
 
@@ -29,6 +29,7 @@
 
 (require 'ox-md)
 (require 'ox-publish)
+
 
 ;;; User-Configurable Variables
 
@@ -56,12 +57,12 @@
   :translate-alist '((inner-template . org-gfm-inner-template)
                      (paragraph . org-gfm-paragraph)
                      (strike-through . org-gfm-strike-through)
+                     (example-block . org-gfm-example-block)
                      (src-block . org-gfm-src-block)
                      (table-cell . org-gfm-table-cell)
                      (table-row . org-gfm-table-row)
                      (table . org-gfm-table)))
 
-
 
 ;;; Transcode Functions
 
@@ -79,12 +80,11 @@ communication channel."
         (replace-regexp-in-string "\\`#" "\\#" contents nil t)
       contents)))
 
-
 ;;;; Src Block
 
-(defun org-gfm-src-block (src-block contents info)
-  "Transcode SRC-BLOCK element into Github Flavored Markdown
-format. CONTENTS is nil.  INFO is a plist used as a communication
+(defun org-gfm-src-block (src-block _contents info)
+  "Transcode SRC-BLOCK element into Github Flavored Markdown format.
+_CONTENTS is nil.  INFO is a plist used as a communication
 channel."
   (let* ((lang (org-element-property :language src-block))
          (code (org-export-format-code-default src-block info))
@@ -92,16 +92,18 @@ channel."
          (suffix "```"))
     (concat prefix code suffix)))
 
+;;;; Example Block
+
+(defalias 'org-gfm-example-block #'org-gfm-src-block)
 
 ;;;; Strike-Through
 
-(defun org-gfm-strike-through (strike-through contents info)
-  "Transcode STRIKE-THROUGH from Org to Markdown (GFM).
-CONTENTS is the text with strike-through markup.  INFO is a plist
+(defun org-gfm-strike-through (_strike-through contents _info)
+  "Transcode _STRIKE-THROUGH from Org to Markdown (GFM).
+CONTENTS is the text with strike-through markup.  _INFO is a plist
 holding contextual information."
   (format "~~%s~~" contents))
 
-
 ;;;; Table-Common
 
 (defvar width-cookies nil)
@@ -112,10 +114,10 @@ holding contextual information."
 (defconst gfm-table-separator " |")
 
 (defun org-gfm-table-col-width (table column info)
-  "Return width of TABLE at given COLUMN. INFO is a plist used as
-communication channel. Width of a column is determined either by
-inquerying `width-cookies' in the column, or by the maximum cell with in
-the column."
+  "Return width of TABLE at given COLUMN.
+INFO is a plist used as communication channel.  Width of a column
+is determined either by inquerying `width-cookies' in the column,
+or by the maximum cell with in the column."
   (let ((cookie (when (hash-table-p width-cookies)
                   (gethash column width-cookies))))
     (if (and (eq table width-cookies-table)
@@ -144,22 +146,21 @@ the column."
             info)
           (puthash column max-width width-cookies))))))
 
-
 (defun org-gfm-make-hline-builder (table info char)
-  "Return a function to build horizontal line in TABLE with given
-CHAR. INFO is a plist used as a communication channel."
-  `(lambda (col)
+  "Return a function to build horizontal line in TABLE with given CHAR.
+INFO is a plist used as a communication channel."
+  (lambda (col)
     (let ((max-width (max 3 (org-gfm-table-col-width table col info))))
       (when (< max-width 1)
         (setq max-width 1))
-       (make-string max-width ,char))))
-
+      (make-string max-width char))))
 
 ;;;; Table-Cell
 
 (defun org-gfm-table-cell (table-cell contents info)
-  "Transcode TABLE-CELL element from Org into GFM. CONTENTS is content
-of the cell. INFO is a plist used as a communication channel."
+  "Transcode TABLE-CELL element from Org into GFM.
+CONTENTS is content of the cell.  INFO is a plist used as a
+communication channel."
   (let* ((table (org-export-get-parent-table table-cell))
          (column (cdr (org-export-table-cell-address table-cell info)))
          (width (org-gfm-table-col-width table column info))
@@ -172,13 +173,12 @@ of the cell. INFO is a plist used as a communication channel."
                                ?\s)))
     (concat left-border contents right-border)))
 
-
 ;;;; Table-Row
 
 (defun org-gfm-table-row (table-row contents info)
-  "Transcode TABLE-ROW element from Org into GFM. CONTENTS is cell
-contents of TABLE-ROW. INFO is a plist used as a communication
-channel."
+  "Transcode TABLE-ROW element from Org into GFM.
+CONTENTS is cell contents of TABLE-ROW.  INFO is a plist used as a
+communication channel."
   (let ((table (org-export-get-parent-table table-row)))
     (when (and (eq 'rule (org-element-property :type table-row))
                ;; In GFM, rule is valid only at second row.
@@ -186,7 +186,6 @@ channel."
                       table-row
                       (org-element-map table 'table-row 'identity info))))
       (let* ((table (org-export-get-parent-table table-row))
-             (header-p (org-export-table-row-starts-header-p table-row info))
              (build-rule (org-gfm-make-hline-builder table info ?-))
              (cols (cdr (org-export-table-dimensions table info))))
         (setq contents
@@ -197,8 +196,6 @@ channel."
                       gfm-table-right-border))))
     contents))
 
-
-
 ;;;; Table
 
 (defun org-gfm-table (table contents info)
@@ -209,7 +206,6 @@ contextual information."
          (no-header (or (<= (length rows) 1)))
          (cols (cdr (org-export-table-dimensions table info)))
          (build-dummy-header
-          (function
           (lambda ()
             (let ((build-empty-cell (org-gfm-make-hline-builder table info ?\s))
                   (build-rule (org-gfm-make-hline-builder table info ?-))
@@ -222,16 +218,14 @@ contextual information."
                       (mapconcat (lambda (col) (funcall build-rule col))
                                  columns
                                  gfm-table-separator)
-                       gfm-table-right-border "\n"))))))
-    (concat (when no-header (funcall build-dummy-header))
+                      gfm-table-right-border "\n")))))
+    (concat (and no-header (funcall build-dummy-header))
             (replace-regexp-in-string "\n\n" "\n" contents))))
 
-
 ;;;; Table of contents
 
-(defun org-gfm-format-toc (headline)
-  "Return an appropriate table of contents entry for HEADLINE. INFO is a
-plist used as a communication channel."
+(defun org-gfm-format-toc (headline info)
+  "Return an appropriate table of contents entry for HEADLINE."
   (let* ((title (org-export-data
                  (org-export-get-alt-title headline info) info))
          (level (1- (org-element-property :level headline)))
@@ -240,38 +234,25 @@ plist used as a communication channel."
                      (org-export-get-reference headline info))))
     (concat indent "- [" title "]" "(#" anchor ")")))
 
-
 ;;;; Footnote section
 
 (defun org-gfm-footnote-section (info)
   "Format the footnote section.
 INFO is a plist used as a communication channel."
-  (let* ((fn-alist (org-export-collect-footnote-definitions info))
-         (fn-alist
-          (cl-loop for (n type raw) in fn-alist collect
-                   (cons n (org-trim (org-export-data raw info))))))
-    (when fn-alist
+  (and-let* ((fn-alist (org-export-collect-footnote-definitions info)))
     (format
-       "## %s\n%s"
-       "Footnotes"
-       (format
-        "\n%s\n"
-        (mapconcat
-         (lambda (fn)
-           (let ((n (car fn)) (def (cdr fn)))
+     "## Footnotes\n\n%s\n"
+     (mapconcat (pcase-lambda (`(,n ,_type ,def))
                   (format
                    "%s %s\n"
-              (format
-               (plist-get info :html-footnote-format)
+                   (format (plist-get info :html-footnote-format)
                            (org-html--anchor
                             (format "fn.%d" n)
                             n
                             (format " class=\"footnum\" href=\"#fnr.%d\"" n)
                             info))
-              def)))
-         fn-alist
-         "\n"))))))
-
+                   (org-trim (org-export-data def info))))
+                fn-alist "\n"))))
 
 ;;;; Template
 
@@ -281,13 +262,13 @@ CONTENTS is the transcoded contents string.  INFO is a plist
 holding export options."
   (let* ((depth (plist-get info :with-toc))
          (headlines (and depth (org-export-collect-headlines info depth)))
-         (toc-string (or (mapconcat 'org-gfm-format-toc headlines "\n") ""))
+         (toc-string (or (mapconcat (lambda (headline)
+                                      (org-gfm-format-toc headline info))
+                                    headlines "\n")
+                         ""))
          (toc-tail (if headlines "\n\n" "")))
     (org-trim (concat toc-string toc-tail contents "\n" (org-gfm-footnote-section info)))))
 
-
-
-
 
 ;;; Interactive function
 
@@ -318,17 +299,16 @@ non-nil."
   (org-export-to-buffer 'gfm "*Org GFM Export*"
     async subtreep visible-only nil nil (lambda () (text-mode))))
 
-
 ;;;###autoload
 (defun org-gfm-convert-region-to-md ()
-  "Assume the current region has org-mode syntax, and convert it
-to Github Flavored Markdown.  This can be used in any buffer.
-For example, you can write an itemized list in org-mode syntax in
-a Markdown buffer and use this command to convert it."
+  "Convert the region to Github Flavored Markdown.
+This can be used in any buffer, this function assume that the
+current region has org-mode syntax.  For example, you can write
+an itemized list in org-mode syntax in a Markdown buffer and use
+this command to convert it."
   (interactive)
   (org-export-replace-region-by 'gfm))
 
-
 ;;;###autoload
 (defun org-gfm-export-to-markdown (&optional async subtreep visible-only)
   "Export current buffer to a Github Flavored Markdown file.