From d95d1874aea9aef168bcf5cf516331fec0a2a1a8 Mon Sep 17 00:00:00 2001
From: Eric Rykwalder <e.rykwalder@gmail.com>
Date: Fri, 11 Mar 2022 17:50:41 -0500
Subject: [PATCH] add ==mark== parsing

---
 __tests__/extensions.ts | 50 +++++++++++++++++++++++++++++++++++------
 src/extensions.ts       | 34 ++++++++++++++++++++--------
 src/index.ts            |  1 +
 3 files changed, 69 insertions(+), 16 deletions(-)

diff --git a/__tests__/extensions.ts b/__tests__/extensions.ts
index cf24a28..5154e39 100644
--- a/__tests__/extensions.ts
+++ b/__tests__/extensions.ts
@@ -15,6 +15,10 @@ const specParser = new SpecParser(parser, {
   cm: "CommentMarker",
   EM: "Embed",
   eM: "EmbedMark",
+  FN: "Footnote",
+  fM: "FootnoteMark",
+  fL: "FootnoteLabel",
+  FR: "FootnoteReference",
   H: "Hashtag",
   hm: "HashtagMark",
   hl: "HashtagLabel",
@@ -23,16 +27,14 @@ const specParser = new SpecParser(parser, {
   iP: "InternalPath",
   iS: "InternalSubpath",
   iD: "InternalDisplay",
-  FN: "Footnote",
-  fM: "FootnoteMark",
-  fL: "FootnoteLabel",
-  FR: "FootnoteReference",
-  YF: "YAMLFrontMatter",
-  ym: "YAMLMarker",
-  yc: "YAMLContent",
+  M: "Mark",
+  mm: "MarkMarker",
   XB: "TexBlock",
   XI: "TexInline",
   xm: "TexMarker",
+  YF: "YAMLFrontMatter",
+  ym: "YAMLMarker",
+  yc: "YAMLContent",
 });
 
 /*
@@ -192,6 +194,40 @@ Line 5}
   Copyright (C) 2020 by Marijn Haverbeke <marijnh@gmail.com> and others
   https://github.com/lezer-parser/markdown/blob/f49eb8c8c82cfe45aa213ca1fe2cebc95305b88b/LICENSE
 */
+  test(
+    "Mark",
+    `
+{P:{M:{mm:==}Hi{mm:==}} Hello, world!}`
+  );
+
+  test(
+    "Mark 2",
+    `
+{P:This ==has a}
+
+{P:new paragraph==.}`
+  );
+
+  test(
+    "Mark (nested)",
+    `
+{P:Nesting {St:{e:**}with {M:{mm:==}emphasis{mm:==}}{e:**}}.}`
+  );
+
+  test(
+    "Mark (overlapping)",
+    `
+{P:One {St:{e:**}two ==three{e:**}} four==}
+
+{P:One {M:{mm:==}two **three{mm:==}} four**}`
+  );
+
+  test(
+    "Mark (escaped)",
+    `
+{P:A {Esc:\\=}=b c==}`
+  );
+
   test(
     "Task list (in unordered list)",
     `
diff --git a/src/extensions.ts b/src/extensions.ts
index 37d78a5..789e072 100644
--- a/src/extensions.ts
+++ b/src/extensions.ts
@@ -13,7 +13,7 @@ import {
 } from "@lezer/markdown";
 
 declare module "@lezer/markdown" {
-  class BlockContext {
+  interface BlockContext {
     readonly input: Input;
     checkedYaml: boolean | null;
   }
@@ -24,7 +24,7 @@ export const Comment: MarkdownConfig = {
   parseBlock: [
     {
       name: "CommentBlock",
-      endLeaf: (cx, line: Line) => {
+      endLeaf: (_, line: Line) => {
         return line.text.slice(line.pos, line.pos + 2) == "%%";
       },
       parse(cx: BlockContext, line: Line) {
@@ -129,7 +129,7 @@ export const Footnote: MarkdownConfig = {
   parseInline: [
     {
       name: "Footnote",
-      parse(cx: InlineContext, _: number, pos: number) {
+      parse(cx: InlineContext, _, pos: number) {
         // typically [^1], but inside can match any characters but
         // square brackets and spaces.
         const match = /^\[\^[^\s[\]]+\]/.exec(cx.text.slice(pos - cx.offset));
@@ -151,7 +151,7 @@ export const Footnote: MarkdownConfig = {
   parseBlock: [
     {
       name: "FootnoteReference",
-      leaf(cx: BlockContext, leaf: LeafBlock): LeafBlockParser | null {
+      leaf(_, leaf: LeafBlock): LeafBlockParser | null {
         const ref = isFootnoteRef(leaf.content);
         if (ref != -1) {
           return new FootnoteReferenceParser(leaf.start + ref);
@@ -176,7 +176,7 @@ export const Hashtag: MarkdownConfig = {
   parseInline: [
     {
       name: "Hashtag",
-      parse(cx, next, pos) {
+      parse(cx: InlineContext, next: number, pos: number) {
         if (next != 35 /* # */) {
           return -1;
         }
@@ -211,7 +211,7 @@ export const InternalLink: MarkdownConfig = {
   parseInline: [
     {
       name: "InternalLink",
-      parse(cx: InlineContext, _: number, pos: number) {
+      parse(cx: InlineContext, _, pos: number) {
         const el = parseInternalLink(cx, pos);
         if (el) {
           return cx.addElement(el);
@@ -339,6 +339,21 @@ function parseDisplay(cx: InlineContext, start: number): Element | null {
   return null;
 }
 
+const MarkDelim = { resolve: "Mark", mark: "MarkMarker" };
+
+export const Mark: MarkdownConfig = {
+  defineNodes: ["Mark", "MarkMarker"],
+  parseInline: [
+    {
+      name: "Mark",
+      parse(cx: InlineContext, next: number, pos: number) {
+        if (next != 61 /* '=' */ || cx.char(pos + 1) != 61) return -1;
+        return cx.addDelimiter(MarkDelim, pos, pos + 2, true, true);
+      },
+    },
+  ],
+};
+
 /*
   Copyright (C) 2020 by Marijn Haverbeke <marijnh@gmail.com> and others
   https://github.com/lezer-parser/markdown/blob/f49eb8c8c82cfe45aa213ca1fe2cebc95305b88b/LICENSE
@@ -370,7 +385,7 @@ export const TaskList: MarkdownConfig = {
   parseBlock: [
     {
       name: "TaskList",
-      leaf(cx, leaf) {
+      leaf(cx: BlockContext, leaf: LeafBlock) {
         return /^\[.\]/.test(leaf.content) && cx.parentType().name == "ListItem"
           ? new TaskParser()
           : null;
@@ -428,7 +443,7 @@ export const Tex: MarkdownConfig = {
   parseInline: [
     {
       name: "TexInline",
-      parse(cx: InlineContext, next: number, pos: number) {
+      parse(cx: InlineContext, _, pos: number) {
         let match = /^\$(?:[^$\t ][^$]*)?[^$\t \\]\$(\D|$)/.exec(
           cx.text.slice(pos - cx.offset)
         );
@@ -453,7 +468,7 @@ export const YAMLFrontMatter: MarkdownConfig = {
   parseBlock: [
     {
       name: "YAMLFrontMatter",
-      parse(cx, line) {
+      parse(cx: BlockContext, line: Line) {
         if (cx.checkedYaml) {
           return false;
         }
@@ -486,6 +501,7 @@ export const ObsidianMDExtensions = [
   Footnote,
   Hashtag,
   InternalLink,
+  Mark,
   Strikethrough,
   Table,
   TaskList,
diff --git a/src/index.ts b/src/index.ts
index 0c3c665..33cee51 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -3,6 +3,7 @@ export {
   Footnote,
   Hashtag,
   InternalLink,
+  Mark,
   ObsidianMDExtensions,
   parser,
   TaskList,