[#133] Add initial math support to GFM

JetBrains · Apr 3, 2024 · 9253d03 · 9253d03
1 parent 31f49df
commit 9253d03
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Showing 9 changed files with 167 additions and 46 deletions.
diff --git a/src/commonMain/kotlin/org/intellij/markdown/flavours/gfm/GFMElementTypes.kt b/src/commonMain/kotlin/org/intellij/markdown/flavours/gfm/GFMElementTypes.kt
@@ -19,6 +19,9 @@ object GFMTokenTypes {
 
     @JvmField
     val CELL: IElementType = MarkdownElementType("CELL", true)
+
+    @JvmField
+    val DOLLAR: IElementType = MarkdownElementType("DOLLAR", true)
 }
 
 object  GFMElementTypes {
@@ -33,4 +36,10 @@ object  GFMElementTypes {
 
     @JvmField
     val ROW: IElementType = MarkdownElementType("ROW")
+
+    @JvmField
+    val INLINE_MATH: IElementType = MarkdownElementType("INLINE_MATH")
+
+    @JvmField
+    val BLOCK_MATH: IElementType = MarkdownElementType("BLOCK_MATH")
 }
diff --git a/src/commonMain/kotlin/org/intellij/markdown/flavours/gfm/GFMFlavourDescriptor.kt b/src/commonMain/kotlin/org/intellij/markdown/flavours/gfm/GFMFlavourDescriptor.kt
@@ -43,6 +43,7 @@ open class GFMFlavourDescriptor(
     override val sequentialParserManager = object : SequentialParserManager() {
         override fun getParserSequence(): List<SequentialParser> {
             return listOf(AutolinkParser(listOf(MarkdownTokenTypes.AUTOLINK, GFMTokenTypes.GFM_AUTOLINK)),
+                    MathParser(),
                     BacktickParser(),
                     ImageParser(),
                     InlineLinkParser(),
@@ -105,7 +106,10 @@ open class GFMFlavourDescriptor(
                     }
                 },
 
-                MarkdownElementTypes.LIST_ITEM to CheckedListItemGeneratingProvider()
-        )
+                MarkdownElementTypes.LIST_ITEM to CheckedListItemGeneratingProvider(),
+
+                GFMElementTypes.INLINE_MATH to MathGeneratingProvider(inline = true),
+                GFMElementTypes.BLOCK_MATH to MathGeneratingProvider()
+          )
     }
 }
diff --git a/src/commonMain/kotlin/org/intellij/markdown/flavours/gfm/GFMGeneratingProviders.kt b/src/commonMain/kotlin/org/intellij/markdown/flavours/gfm/GFMGeneratingProviders.kt
@@ -11,7 +11,6 @@ import org.intellij.markdown.html.InlineHolderGeneratingProvider
 import org.intellij.markdown.html.SimpleTagProvider
 import org.intellij.markdown.html.entities.EntityConverter
 import org.intellij.markdown.lexer.Compat.assert
-import kotlin.text.Regex
 
 internal class CheckedListItemGeneratingProvider : SimpleTagProvider("li") {
     override fun openTag(visitor: HtmlGenerator.HtmlGeneratingVisitor, text: String, node: ASTNode) {
@@ -152,6 +151,16 @@ open class TableAwareCodeSpanGeneratingProvider : GeneratingProvider {
     }
 }
 
+internal class MathGeneratingProvider(private val inline: Boolean = false): GeneratingProvider {
+    override fun processNode(visitor: HtmlGenerator.HtmlGeneratingVisitor, text: String, node: ASTNode) {
+        val nodes = node.children.subList(1, node.children.size - 1)
+        val output = nodes.joinToString(separator = "") { HtmlGenerator.leafText(text, it, false) }.trim()
+        visitor.consumeTagOpen(node, "span", "class=\"math\"", "inline = \"$inline\"")
+        visitor.consumeHtml(output)
+        visitor.consumeTagClose("span")
+    }
+}
+
 internal class TablesGeneratingProvider : GeneratingProvider {
     override fun processNode(visitor: HtmlGenerator.HtmlGeneratingVisitor, text: String, node: ASTNode) {
         assert(node.type == GFMElementTypes.TABLE)

diff --git a/src/commonMain/kotlin/org/intellij/markdown/flavours/gfm/lexer/_GFMLexer.kt b/src/commonMain/kotlin/org/intellij/markdown/flavours/gfm/lexer/_GFMLexer.kt
diff --git a/src/commonMain/kotlin/org/intellij/markdown/flavours/gfm/lexer/gfm.flex b/src/commonMain/kotlin/org/intellij/markdown/flavours/gfm/lexer/gfm.flex
@@ -286,6 +286,14 @@ GFM_AUTOLINK = (("http" "s"? | "ftp" | "file")"://" | "www.") {HOST_PART} ("." {
     return parseDelimited.returnType;
   }
 
+  // Math
+  "$"+ {
+    if (canInline()) {
+      return GFMTokenTypes.DOLLAR;
+    }
+    return parseDelimited.returnType;
+  }
+
   // Emphasis
   {WHITE_SPACE}+ ("*" | "_") {WHITE_SPACE}+ {
     return getReturnGeneralized(MarkdownTokenTypes.TEXT);

diff --git a/src/commonMain/kotlin/org/intellij/markdown/parser/sequentialparsers/impl/MathParser.kt b/src/commonMain/kotlin/org/intellij/markdown/parser/sequentialparsers/impl/MathParser.kt
@@ -0,0 +1,50 @@
+package org.intellij.markdown.parser.sequentialparsers.impl
+
+import org.intellij.markdown.flavours.gfm.GFMElementTypes
+import org.intellij.markdown.flavours.gfm.GFMTokenTypes
+import org.intellij.markdown.parser.sequentialparsers.RangesListBuilder
+import org.intellij.markdown.parser.sequentialparsers.SequentialParser
+import org.intellij.markdown.parser.sequentialparsers.TokensCache
+
+class MathParser : SequentialParser {
+    override fun parse(tokens: TokensCache, rangesToGlue: List<IntRange>): SequentialParser.ParsingResult {
+        val result = SequentialParser.ParsingResultBuilder()
+        val delegateIndices = RangesListBuilder()
+        var iterator: TokensCache.Iterator = tokens.RangesListIterator(rangesToGlue)
+
+        while (iterator.type != null) {
+            if (iterator.type == GFMTokenTypes.DOLLAR) {
+
+                val endIterator = findOfSize(iterator.advance(), iterator.length)
+
+                if (endIterator != null) {
+                    if (iterator.length == 1) {
+                        result.withNode(SequentialParser.Node(iterator.index..endIterator.index + 1, GFMElementTypes.INLINE_MATH))
+                    } else {
+                        result.withNode(SequentialParser.Node(iterator.index..endIterator.index + 1, GFMElementTypes.BLOCK_MATH))
+                    }
+                    iterator = endIterator.advance()
+                    continue
+                }
+            }
+            delegateIndices.put(iterator.index)
+            iterator = iterator.advance()
+        }
+
+        return result.withFurtherProcessing(delegateIndices.get())
+    }
+
+    private fun findOfSize(it: TokensCache.Iterator, length: Int): TokensCache.Iterator? {
+        var iterator = it
+        while (iterator.type != null) {
+            if (iterator.type == GFMTokenTypes.DOLLAR) {
+                if (iterator.length == length) {
+                    return iterator
+                }
+            }
+
+            iterator = iterator.advance()
+        }
+        return null
+    }
+}
diff --git a/src/fileBasedTest/kotlin/org/intellij/markdown/MarkdownParsingTest.kt b/src/fileBasedTest/kotlin/org/intellij/markdown/MarkdownParsingTest.kt
@@ -342,6 +342,11 @@ Markdown:MARKDOWN_FILE
         defaultTest(GFMFlavourDescriptor())
     }
 
+    @Test
+    fun testMath() {
+        defaultTest(GFMFlavourDescriptor())
+    }
+
     @Test
     fun testBrokenTable() {
         defaultTest(GFMFlavourDescriptor())

diff --git a/src/fileBasedTest/resources/data/parser/math.md b/src/fileBasedTest/resources/data/parser/math.md
@@ -0,0 +1,3 @@
+This expression uses `\$` to display a dollar sign: $\sqrt{\$4}$
+
+$$\sum_{k=1}^n a_k^2$$
diff --git a/src/fileBasedTest/resources/data/parser/math.txt b/src/fileBasedTest/resources/data/parser/math.txt
@@ -0,0 +1,26 @@
+Markdown:MARKDOWN_FILE
+  Markdown:PARAGRAPH
+    Markdown:TEXT('This expression uses')
+    WHITE_SPACE(' ')
+    Markdown:CODE_SPAN
+      Markdown:BACKTICK('`')
+      Markdown:TEXT('\$')
+      Markdown:BACKTICK('`')
+    WHITE_SPACE(' ')
+    Markdown:TEXT('to display a dollar sign')
+    Markdown::(':')
+    WHITE_SPACE(' ')
+    Markdown:INLINE_MATH
+      Markdown:DOLLAR('$')
+      Markdown:TEXT('\sqrt{\$4}')
+      Markdown:DOLLAR('$')
+  Markdown:EOL('\n')
+  Markdown:EOL('\n')
+  Markdown:PARAGRAPH
+    Markdown:BLOCK_MATH
+      Markdown:DOLLAR('$$')
+      Markdown:TEXT('\sum')
+      Markdown:EMPH('_')
+      Markdown:TEXT('{k=1}^n a_k^2')
+      Markdown:DOLLAR('$$')
+  Markdown:EOL('\n')
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		This expression uses `\$` to display a dollar sign: $\sqrt{\$4}$

		$$\sum_{k=1}^n a_k^2$$