From 38f708452bc1032ee1e42cf0e345ca8851316e4a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hugo=20H=C3=B6rnquist?= <hugo@lysator.liu.se>
Date: Mon, 1 Jun 2020 16:02:54 +0200
Subject: Break text procedures into modules.

---
 module/text/markup.scm | 117 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 module/text/markup.scm

(limited to 'module/text/markup.scm')

diff --git a/module/text/markup.scm b/module/text/markup.scm
new file mode 100644
index 00000000..62b6ebe4
--- /dev/null
+++ b/module/text/markup.scm
@@ -0,0 +1,117 @@
+(define-module (text markup)
+  :use-module (util)
+  :use-module (srfi srfi-1)
+  :use-module (ice-9 match)
+  :use-module (ice-9 pretty-print)
+  :use-module (text util)
+  :use-module (text flow)
+  :use-module (texinfo string-utils))
+
+
+(define (esc . effect)
+  (format #f "\x1b[~am"
+          (if (null? effect)
+              ""
+              (case (car effect)
+                [(bold) 1]
+                [(italic) 3]
+                [(invert) 7]
+                [else 4]))))
+
+
+(define (add-attributes args)
+  (match-lambda
+    [(name ('@ tagargs ...) body ...)
+     `(,name (@ ,@(assq-limit (assq-merge tagargs args)))
+             ,@body)]
+    [(name body ...)
+     `(,name (@ ,@args) ,@body)]
+    [nonlist nonlist]))
+
+
+(define (get-attr args key default)
+  (aif (assoc-ref args key)
+       (car it) default))
+
+;; NOTE width is hard coded to 70 chars
+(define* (ontree tag body optional: (args '()))
+  (case tag
+    [(*TOP* group block) (string-concatenate
+                          (map (compose sxml->ansi-text (add-attributes args))
+                               body))]
+    [(header) (sxml->ansi-text `(group (center (@ ,@args) (b ,@body)) (br)))]
+    [(center) (center-string (string-concatenate (map sxml->ansi-text body))
+                             (get-attr args 'width 70))]
+    [(p) (string-append (string-join (flow-text (string-concatenate (map sxml->ansi-text body))
+                                                width: (get-attr args 'width 70))
+                                     "\n")
+                        (if (assoc-ref args 'inline) "" "\n\n")
+                        )]
+    [(b) (string-append (esc 'bold) (string-concatenate (map sxml->ansi-text body)) (esc))]
+    [(i em) (string-append (esc 'italic) (string-concatenate (map sxml->ansi-text body)) (esc))]
+    ;; NOOP, but for future use.
+    [(code) (string-concatenate (map sxml->ansi-text body))]
+    [(blockquote) (string-concatenate
+                   (map (lambda (line) (sxml->ansi-text `(group (ws (@ (minwidth 4))) ,line (br))))
+                        (flow-text
+                         (string-concatenate (map sxml->ansi-text body))
+                         width: 66)))]
+    [(ws) (make-string  (aif (assoc-ref args 'minwidth)
+                             (car it) 1)
+                        #\space)]
+    [(br) "\n"]
+    [(hr) (string-append "     " (make-string 60 #\_) "     \n")]
+    [(dl)
+     (let* ((dts dds (partition (lambda (x) (eq? 'dt (car x))) body)))
+       (let* ((dts* (map sxml->ansi-text dts))
+              (m (if (null? dts*) 0 (apply max (map true-string-length dts*)))))
+         (string-concatenate
+          (map (lambda (dt dd)
+                 (let ((dds (string-split dd #\newline)))
+                   (string-concatenate
+                    (map (lambda (left right)
+                           (string-append (true-string-pad left m) " │ " right "\n"))
+                         (cons dt (map (const "") (iota (1- (length dds)))))
+                         dds))))
+               dts*
+               (map (compose sxml->ansi-text (add-attributes `((width ,(- 70 m 5)))))
+                    dds)))))]
+    [(dt) (string-concatenate (map (compose sxml->ansi-text (add-attributes args))
+                                   body))]
+    [(dd)
+     (string-concatenate
+      (map (compose sxml->ansi-text (add-attributes args))
+           body))]
+
+    [(scheme)
+     (string-concatenate
+      (map (lambda (form)
+             (with-output-to-string
+               (lambda () (pretty-print form width: (aif (assoc-ref args 'width) (car it) 70)))))
+           body))]
+
+    [else (string-append (esc 'bold) "??"
+                         "`"
+                         (esc 'invert)
+                         (string-concatenate (map sxml->ansi-text body))
+                         (esc) "'")]
+    )
+  )
+
+(define (onleaf leaf)
+  (format #f "~a" leaf))
+
+(define (parse-tree tree-callback leaf-callback)
+  (match-lambda
+    [(tag ('@ args ...) body ...)
+     (tree-callback tag body args)]
+    [(tag body ...)
+     (tree-callback tag body)
+     ]
+    [() ""]
+    [(any ...) (map leaf-callback any)]
+    [any (leaf-callback any)]))
+
+
+(define-public (sxml->ansi-text tree)
+  ((parse-tree ontree onleaf) tree))
-- 
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