From 913ca874b31eaf87ed5996b2856a45e7512f028f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?D=C3=A1niel=20Stein?= <daniel@stein.hu>
Date: Sat, 13 May 2017 23:47:19 +0200
Subject: [PATCH] Include only a portion of a file (issue #8)

---
 IncludeFilter.hs | 18 ++++++++++++++++++
 test/input.md    |  5 +++++
 2 files changed, 23 insertions(+)

diff --git a/IncludeFilter.hs b/IncludeFilter.hs
index 7599b03..00d209b 100644
--- a/IncludeFilter.hs
+++ b/IncludeFilter.hs
@@ -104,9 +104,27 @@ includeCodeBlock (CodeBlock (_, classes, _) list) = do
   let blocks = fmap (B.codeBlockWith ("", newclasses, [])) content
   fmap B.toList blocks
 
+cropContent :: [String] -> (String, String) -> [String]
+cropContent lines (skip, count) =
+  if not $ null skip then
+    if not $ null count then
+      take (read count) (drop (read skip) lines)
+    else
+      drop (read skip) lines
+  else
+    lines
+
+includeCropped :: Block -> IO [Block]
+includeCropped (CodeBlock (_, classes, _) list) = do
+  let [filePath, skip, count] = lines list
+  let content = fileContentAsString filePath
+  let croppedContent = unlines <$> ((cropContent . lines <$> content) <*> pure (skip, count))
+  fmap (stripPandoc . readMarkdown def) croppedContent
+
 doInclude :: Block -> IO [Block]
 doInclude cb@(CodeBlock (_, classes, _) list)
   | "code" `elem` classes = includeCodeBlock cb
+  | "cropped" `elem` classes = includeCropped cb
   | "include" `elem` classes = simpleInclude list classes
 doInclude x = return [x]
 
diff --git a/test/input.md b/test/input.md
index 000f668..544bcb3 100644
--- a/test/input.md
+++ b/test/input.md
@@ -10,5 +10,10 @@ gamma.md
 ```include
 beta.md
 ```
+```cropped
+alpha.md
+2
+1
+```
 
 text