From 5d164d216c06de2ae0f79ded44476b00b2de95b8 Mon Sep 17 00:00:00 2001
From: vmishenev <vad-mishenev@yandex.ru>
Date: Mon, 11 Apr 2022 04:43:41 +0300
Subject: [PATCH] Support code fence of tildes

---
 .../base/src/main/kotlin/parsers/Parser.kt    | 62 ++++++++++++++-----
 1 file changed, 46 insertions(+), 16 deletions(-)

diff --git a/plugins/base/src/main/kotlin/parsers/Parser.kt b/plugins/base/src/main/kotlin/parsers/Parser.kt
index ec55c321af..50857685ee 100644
--- a/plugins/base/src/main/kotlin/parsers/Parser.kt
+++ b/plugins/base/src/main/kotlin/parsers/Parser.kt
@@ -11,7 +11,7 @@ abstract class Parser {
     abstract fun preparse(text: String): String
 
     open fun parse(text: String): DocumentationNode =
-        DocumentationNode(jkdocToListOfPairs(preparse(text)).map { (tag, content) -> parseTagWithBody(tag, content) })
+        DocumentationNode(extractTagsToListOfPairs(preparse(text)).map { (tag, content) -> parseTagWithBody(tag, content) })
 
     open fun parseTagWithBody(tagName: String, content: String): TagWrapper =
         when (tagName) {
@@ -49,18 +49,29 @@ abstract class Parser {
             else -> CustomTagWrapper(parseStringToDocNode(content), tagName)
         }
 
-    private fun jkdocToListOfPairs(javadoc: String): List<Pair<String, String>> =
-        "description $javadoc"
-            .splitIgnoredInsideBackticks("\n@")
+    /**
+     * KDoc parser from Kotlin compiler relies on a comment asterisk
+     * So there is a mini parser here
+     * TODO: at least to adapt [org.jetbrains.kotlin.kdoc.lexer.KDocLexer] to parse KDoc without the asterisks and use it here
+     */
+    private fun extractTagsToListOfPairs(text: String): List<Pair<String, String>> =
+        "description $text"
+            .extractKDocSections()
             .map { content ->
                 val contentWithEscapedAts = content.replace("\\@", "@")
                 val (tag, body) = contentWithEscapedAts.split(" ", limit = 2)
                 tag to body
             }
 
-    private fun CharSequence.splitIgnoredInsideBackticks(delimiter: String): List<String> {
+    /**
+     * Ignore a doc tag inside code spans and blocks
+     * @see org.jetbrains.kotlin.kdoc.psi.impl.KDocSection
+     */
+    private fun CharSequence.extractKDocSections(delimiter: String = "\n@"): List<String> {
         var countOfBackticks = 0
+        var countOfTildes = 0
         var countOfBackticksInOpeningFence = 0
+        var countOfTildesInOpeningFence = 0
 
         var isInCode = false
         val result = mutableListOf<String>()
@@ -69,19 +80,38 @@ abstract class Parser {
         var currentOffset = 0
         while (currentOffset < length) {
 
-            if (get(currentOffset) == '`') {
-                countOfBackticks++
-            } else {
-                if (isInCode) {
-                    // The closing code fence must be at least as long as the opening fence
-                    isInCode = countOfBackticks < countOfBackticksInOpeningFence
-                } else {
-                    if (countOfBackticks > 0) {
-                        isInCode = true
-                        countOfBackticksInOpeningFence = countOfBackticks
+            when (get(currentOffset)) {
+                '`' -> {
+                    countOfBackticks++
+                    countOfTildes = 0
+                }
+                '~' -> {
+                    countOfTildes++
+                    countOfBackticks = 0
+                }
+                else -> {
+                    if (isInCode) {
+                        // The closing code fence must be at least as long as the opening fence
+                        if(countOfBackticks >= countOfBackticksInOpeningFence
+                                || countOfTildes >= countOfTildesInOpeningFence)
+                            isInCode = false
+                    } else {
+                        // as per CommonMark spec, there can be any number of backticks for a code span, not only one or three
+                        if (countOfBackticks > 0) {
+                            isInCode = true
+                            countOfBackticksInOpeningFence = countOfBackticks
+                            countOfTildesInOpeningFence = Int.MAX_VALUE
+                        }
+                        // tildes are only for a code block, not code span
+                        if (countOfTildes >= 3) {
+                            isInCode = true
+                            countOfTildesInOpeningFence = countOfTildes
+                            countOfBackticksInOpeningFence = Int.MAX_VALUE
+                        }
                     }
+                    countOfTildes = 0
+                    countOfBackticks = 0
                 }
-                countOfBackticks = 0
             }
             if (!isInCode && startsWith(delimiter, currentOffset)) {
                 result.add(substring(rangeStart, rangeEnd))