post: Add convenience procedures for post author, tags, and title.

Author, tags and title metadata are commonly used,

* haunt/post.scm (post-author, post-tags, post-title): New procedures.
* tests/post.scm ("post-author, author metadata", "post-tags, tags
metadata", "post-title, title metadata", "post-author, no metadata",
"post-tags, no metadata", "post-title, no metadata"): New tests.
* doc/haunt.texi (Posts): Docs for new procedures.

1 files changed, 26 insertions, 0 deletions

diff --git a/tests/post.scm b/tests/post.scm
index db1a82c..d01ed84 100644
--- a/tests/post.scm
+++ b/tests/post.scm
@@ -53,6 +53,32 @@
       (list newest middle oldest)
       (posts/reverse-chronological (list oldest newest middle))))
 
+  (let ((example-post (make-post "foo.skr"
+                        '((author . "Eva Luator")
+                          (tags "foo" "bar" "baz")
+                          (title . "Hello, world!"))
+                        '())))
+    (test-equal "post-author, author metadata"
+      "Eva Luator"
+      (post-author example-post))
+    (test-equal "post-tags, tags metadata"
+      '("foo" "bar" "baz")
+      (post-tags example-post))
+    (test-equal "post-title, title metadata"
+      "Hello, world!"
+      (post-title example-post)))
+
+  (let ((no-metadata-post (make-post "foo.skr" '() '())))
+    (test-equal "post-author, no metadata"
+      #f
+      (post-author no-metadata-post))
+    (test-equal "post-tags, no metadata"
+      '()
+      (post-tags no-metadata-post))
+    (test-equal "post-title, no metadata"
+      #f
+      (post-title no-metadata-post)))
+
   (let ((foo-post (make-post "foo.skr" '((tags "foo")) '()))
         (another-foo-post (make-post "another-foo.skr" '((tags "foo")) '()))
         (bar-post (make-post "bar.skr" '((tags "bar")) '())))