Add generic inline parse loop support

2 files changed, 31 insertions, 32 deletions

diff --git a/src/main/kotlin/moe/nea/blog/md/ItalicsParser.kt b/src/main/kotlin/moe/nea/blog/md/ItalicsParser.kt
index d3c9d5d..9f60200 100644
--- a/src/main/kotlin/moe/nea/blog/md/ItalicsParser.kt
+++ b/src/main/kotlin/moe/nea/blog/md/ItalicsParser.kt
@@ -17,19 +17,10 @@ object ItalicsParser : InlineParser {
 
         if (firstStarCount < 1 || firstStarCount > 3) error("Invalid italics/bold sequence")
 
-        val isBold = firstStarCount >= 2
-        val isItalics = (firstStarCount % 2) == 1
-
-        val firstSequence = mutableListOf<MarkdownFormat>()
-        var remainingText = text.substring(firstStarCount)
-        var lastToken: MarkdownFormat = Begin() // TODO: dedicated begin token
-        while (remainingText.isNotEmpty()) {
-            val (element, next) = parser.parseInlineTextOnce(lastToken, remainingText)
-            remainingText = next
-            lastToken = element
-            firstSequence.add(element)
-            if (element !is Whitespace && next.startsWith("*")) break
-        }
+        var (firstSequence, remainingText) = parser.parseInlineTextUntil(
+            text.substring(firstStarCount),
+            Begin()
+        ) { lookback, remaining -> lookback !is Whitespace && remaining.startsWith("*") } // TODO: free standing *
 
         var secondStarCount = 0
         while (secondStarCount in remainingText.indices) {
@@ -51,15 +42,11 @@ object ItalicsParser : InlineParser {
             return Pair(firstElement, remainingText)
         }
 
-        val secondSequence = mutableListOf<MarkdownFormat>()
-        lastToken = Begin()
-        while (remainingText.isNotEmpty()) {
-            val (element, next) = parser.parseInlineTextOnce(lastToken, remainingText)
-            remainingText = next
-            lastToken = element
-            secondSequence.add(element)
-            if (element !is Whitespace && next.startsWith("*")) break
+        // TODO: better begin
+        val (secondSequence, _remainingText) = parser.parseInlineTextUntil(remainingText, Begin()) { lookback, remaining ->
+            lookback !is Whitespace && remaining.startsWith("*")
         }
+        remainingText = _remainingText
 
         var thirdStarCount = 0
         while (thirdStarCount in remainingText.indices) {
@@ -75,7 +62,7 @@ object ItalicsParser : InlineParser {
         if (thirdStarCount != firstStarCount - secondStarCount) {
             error("Invalid italics/bold sequence")
         }
-        var secondElement = parser.collapseInlineFormat(secondSequence, false)
+        val secondElement = parser.collapseInlineFormat(secondSequence, false)
         var combined: MarkdownFormat = FormatSequence(firstElement, secondElement)
         if (thirdStarCount == 1)
             combined = Italics(combined)
diff --git a/src/main/kotlin/moe/nea/blog/md/MarkdownParser.kt b/src/main/kotlin/moe/nea/blog/md/MarkdownParser.kt
index 144eeda..19a4e99 100644
--- a/src/main/kotlin/moe/nea/blog/md/MarkdownParser.kt
+++ b/src/main/kotlin/moe/nea/blog/md/MarkdownParser.kt
@@ -50,6 +50,25 @@ class MarkdownParser(source: String) {
         return line.substring(blockIndents)
     }
 
+    fun parseInlineTextUntil(
+        text: String,
+        initialLookback: MarkdownFormat,
+        breakout: (lookback: MarkdownFormat, remaining: String) -> Boolean
+    ): Pair<List<MarkdownFormat>, String> {
+        val seq = mutableListOf<MarkdownFormat>()
+        var remaining = text
+        var lastToken: MarkdownFormat = initialLookback
+        while (remaining.isNotEmpty()) {
+            val (tok, next) = parseInlineTextOnce(lastToken, remaining)
+            seq.add(tok)
+            lastToken = tok
+            remaining = next
+            if (breakout(tok, next))
+                break
+        }
+        return seq to remaining
+    }
+
     fun parseInlineTextOnce(lookback: MarkdownFormat, text: String): Pair<MarkdownFormat, String> {
         val parser = inlineParsers.find { it.detect(lookback, text) }
         if (parser != null)
@@ -66,16 +85,9 @@ class MarkdownParser(source: String) {
     }
 
     fun parseInlineText(text: String): MarkdownFormat {
-        val seq = mutableListOf<MarkdownFormat>()
-        var remaining = text
-        var lastToken: MarkdownFormat = Begin()
-        while (remaining.isNotEmpty()) {
-            val (tok, next) = parseInlineTextOnce(lastToken, remaining)
-            seq.add(tok)
-            lastToken = tok
-            remaining = next
-        }
-        return collapseInlineFormat(seq, true)
+        val (tokens, rest) = parseInlineTextUntil(text, Begin()) { _, _ -> false }
+        require(rest.isEmpty())
+        return collapseInlineFormat(tokens, true)
     }
 
     private fun expandMarkdownFormats(sequence: List<MarkdownFormat>): List<MarkdownFormat> {