Add prefix ignoring line processor

2 files changed, 17 insertions, 12 deletions

diff --git a/src/main/kotlin/moe/nea/blog/md/LinePreProcessor.kt b/src/main/kotlin/moe/nea/blog/md/LinePreProcessor.kt
index cb9d81f..7938cbe 100644
--- a/src/main/kotlin/moe/nea/blog/md/LinePreProcessor.kt
+++ b/src/main/kotlin/moe/nea/blog/md/LinePreProcessor.kt
@@ -1,5 +1,13 @@
 package moe.nea.blog.md
 
-interface LinePreProcessor {
+fun interface LinePreProcessor {
     fun preprocess(lineIndex: Int, line: String): String?
+
+    companion object {
+        fun whileIgnoringFirst(indent: Int, wrapped: LinePreProcessor): LinePreProcessor {
+            return LinePreProcessor { lineIndex, line ->
+                line.take(indent) + wrapped.preprocess(lineIndex, line.drop(indent))
+            }
+        }
+    }
 }
diff --git a/src/main/kotlin/moe/nea/blog/md/ListParser.kt b/src/main/kotlin/moe/nea/blog/md/ListParser.kt
index 7d1e63b..8175c1a 100644
--- a/src/main/kotlin/moe/nea/blog/md/ListParser.kt
+++ b/src/main/kotlin/moe/nea/blog/md/ListParser.kt
@@ -13,18 +13,15 @@ object ListParser : BlockParser {
         val prefix = line.substring(0, indentSize + 2)
         var bypassLineIndex = parser.getLineIndex()
         val indentDepth = parser.getIndent()
-        val processor = object : LinePreProcessor {
-            override fun preprocess(lineIndex: Int, line: String): String? {
-                if (line.substring(indentDepth).startsWith(prefix)) {
-                    if (bypassLineIndex == lineIndex) {
-                        return line.substring(0, indentDepth) +
-                                " ".repeat(indentSize + 2) +
-                                line.substring(indentDepth + indentSize + 2)
-                    } else {
-                        return null
-                    }
+        val processor = LinePreProcessor.whileIgnoringFirst(indentDepth) { lineIndex, line ->
+            if (line.startsWith(prefix)) {
+                if (bypassLineIndex == lineIndex) {
+                    " ".repeat(indentSize + 2) + line.substring(indentSize + 2)
+                } else {
+                    null
                 }
-                return line
+            } else {
+                line
             }
         }
         parser.pushPreProcessor(processor)