Add list parser

6 files changed, 151 insertions, 7 deletions

diff --git a/src/main/kotlin/moe/nea/blog/md/BlockList.kt b/src/main/kotlin/moe/nea/blog/md/BlockList.kt
new file mode 100644
index 0000000..ce51a58
--- /dev/null
+++ b/src/main/kotlin/moe/nea/blog/md/BlockList.kt
@@ -0,0 +1,12 @@
+package moe.nea.blog.md
+
+import java.io.PrintStream
+
+data class BlockList(val elements: List<MarkdownBlock>) : MarkdownBlock {
+    override fun debugFormat(indent: Int, printStream: PrintStream) {
+        elements.forEach {
+            it.debugFormat(indent, printStream)
+        }
+    }
+
+}
diff --git a/src/main/kotlin/moe/nea/blog/md/LinePreProcessor.kt b/src/main/kotlin/moe/nea/blog/md/LinePreProcessor.kt
new file mode 100644
index 0000000..cb9d81f
--- /dev/null
+++ b/src/main/kotlin/moe/nea/blog/md/LinePreProcessor.kt
@@ -0,0 +1,5 @@
+package moe.nea.blog.md
+
+interface LinePreProcessor {
+    fun preprocess(lineIndex: Int, line: String): String?
+}
diff --git a/src/main/kotlin/moe/nea/blog/md/ListParser.kt b/src/main/kotlin/moe/nea/blog/md/ListParser.kt
new file mode 100644
index 0000000..7d1e63b
--- /dev/null
+++ b/src/main/kotlin/moe/nea/blog/md/ListParser.kt
@@ -0,0 +1,60 @@
+package moe.nea.blog.md
+
+import moe.nea.blog.util.indentSize
+
+object ListParser : BlockParser {
+    override fun detect(line: String): Boolean {
+        return line.matches(" *[*+-] .*".toRegex())
+    }
+
+    override fun parse(parser: MarkdownParser): MarkdownBlock {
+        val line = parser.peekLine()!!
+        val indentSize = line.indentSize()!!
+        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
+                    }
+                }
+                return line
+            }
+        }
+        parser.pushPreProcessor(processor)
+        parser.pushIndent(indentSize + 2)
+
+        val listItems = mutableListOf<MarkdownBlock>()
+
+        while (true) {
+            bypassLineIndex = parser.getLineIndex()
+            val elements = mutableListOf<MarkdownBlock>()
+            while (true) {
+                val child = parser.readChildBlock() ?: break
+                elements.add(child)
+            }
+            parser.popPreProcessor()
+            parser.popIndent()
+            val realLine = parser.peekLine()
+            parser.pushPreProcessor(processor)
+            parser.pushIndent(indentSize + 2)
+            listItems.add(parser.mergeBlocks(elements))
+            if (realLine == null || !realLine.startsWith(prefix)) {
+                break
+            }
+        }
+
+        parser.popIndent()
+        parser.popPreProcessor()
+        return MDList(listItems)
+    }
+
+    override val prio: Int
+        get() = 10
+}
\ No newline at end of file
diff --git a/src/main/kotlin/moe/nea/blog/md/MDList.kt b/src/main/kotlin/moe/nea/blog/md/MDList.kt
new file mode 100644
index 0000000..6fd0f74
--- /dev/null
+++ b/src/main/kotlin/moe/nea/blog/md/MDList.kt
@@ -0,0 +1,24 @@
+package moe.nea.blog.md
+
+import moe.nea.blog.util.indent
+import java.io.PrintStream
+
+data class MDList(
+    val elements: List<MarkdownBlock>
+) : MarkdownBlock {
+    override fun debugFormat(indent: Int, printStream: PrintStream) {
+        printStream.indent(indent)
+        printStream.println("<list>")
+
+        elements.forEach {
+            printStream.indent(indent + 2)
+            printStream.println("<element>")
+            it.debugFormat(indent + 4, printStream)
+            printStream.indent(indent + 2)
+            printStream.println("</element>")
+        }
+
+        printStream.indent(indent)
+        printStream.println("</list>")
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/moe/nea/blog/md/MarkdownParser.kt b/src/main/kotlin/moe/nea/blog/md/MarkdownParser.kt
index ad818dd..aaac6a1 100644
--- a/src/main/kotlin/moe/nea/blog/md/MarkdownParser.kt
+++ b/src/main/kotlin/moe/nea/blog/md/MarkdownParser.kt
@@ -12,6 +12,8 @@ class MarkdownParser(source: String) {
 
     private val blockParsers = mutableListOf<BlockParser>()
     private val inlineParsers = mutableListOf<InlineParser>()
+    private val preprocessors = Stack<LinePreProcessor>()
+    private var peekedLine: String? = null
 
     fun findParserFor(line: String): BlockParser? {
         return blockParsers.filter { it.detect(line) }
@@ -24,30 +26,58 @@ class MarkdownParser(source: String) {
         return blockParser.parse(this)
     }
 
+    fun pushPreProcessor(preProcessor: LinePreProcessor) {
+        peekedLine = null
+        preprocessors.push(preProcessor)
+    }
+
+    fun popPreProcessor() {
+        peekedLine = null
+        preprocessors.pop()
+    }
+
+    fun preProcessLine(string: String): String? {
+        var acc = string
+        for (processor in preprocessors) {
+            acc = processor.preprocess(lineIndex, acc) ?: return null
+        }
+        return acc
+    }
+
     fun pushIndent(newIndent: Int) {
-        require(newIndent > blockIndents)
         indentStack.push(blockIndents)
-        blockIndents = newIndent
+        blockIndents += newIndent
+        peekedLine = null
     }
 
     fun popIndent() {
         blockIndents = indentStack.pop()
+        peekedLine = null
+    }
+
+    fun unpeekLine() {
+        peekedLine = null
     }
 
     fun consumeLine(): String? {
         val line = peekLine()
-        if (line != null)
+        if (line != null) {
+            peekedLine = null
             lineIndex++
+        }
         return line
     }
 
     fun peekLine(): String? {
         if (lineIndex !in lines.indices) return null
-        val line = lines[lineIndex]
+        val line = peekedLine ?: preProcessLine(lines[lineIndex]) ?: return null
+        peekedLine = line
         val indent = line.indentSize()
-        if (indent != null && indent < blockIndents)
+        if (indent != null && indent < blockIndents) {
+            peekedLine = null
             return null
-        return line.substring(blockIndents)
+        }
+        return line.drop(blockIndents)
     }
 
     fun parseInlineTextUntil(
@@ -139,8 +169,21 @@ class MarkdownParser(source: String) {
     fun addDefaultParsers() {
         blockParsers.add(CodeBlockParser)
         blockParsers.add(HeaderParser)
+        blockParsers.add(ListParser)
         inlineParsers.add(ItalicsParser)
         inlineParsers.add(LinkParser)
     }
+
+    fun getLineIndex(): Int {
+        return lineIndex
+    }
+
+    fun mergeBlocks(elements: List<MarkdownBlock>): MarkdownBlock {
+        return elements.singleOrNull() ?: BlockList(elements)
+    }
+
+    fun getIndent(): Int {
+        return blockIndents
+    }
 }
 
diff --git a/src/main/kotlin/moe/nea/blog/md/ParagraphParser.kt b/src/main/kotlin/moe/nea/blog/md/ParagraphParser.kt
index 328c49b..5e51786 100644
--- a/src/main/kotlin/moe/nea/blog/md/ParagraphParser.kt
+++ b/src/main/kotlin/moe/nea/blog/md/ParagraphParser.kt
@@ -17,7 +17,7 @@ object ParagraphParser : BlockParser {
             } else {
                 emptyLineCount = 0
             }
-            if (emptyLineCount == 2) {
+            if (emptyLineCount == 1) {
                 break
             }
             text += " $trimmedLine"