fix: Markdown lexer

lexilla/lexers/LexMarkdown.cxx

@@ -1,4 +1,4 @@
-/******************************************************************
+ /******************************************************************
  *  LexMarkdown.cxx
  *
  *  A simple Markdown lexer for scintilla.
@@ -119,7 +119,21 @@ bool HasPrevLineContent(StyleContext &sc) {
 }
 
 bool AtTermStart(const StyleContext &sc) noexcept {
-    return sc.currentPos == 0 || sc.chPrev == 0 || isspacechar(sc.chPrev);
+    if (sc.currentPos == 0 || sc.chPrev == 0 || isspacechar(sc.chPrev))
+        return true;
+    // NP3 patch: also accept common opening punctuation so inline spans
+    // (code, strong, emphasis, strikeout) can open directly after them,
+    // e.g. (`x`), [`x`], {`x`}, <`x`>, "`x`", '`x`'. CommonMark and VS
+    // Code accept these — code spans have no left-flank restriction at
+    // all, and emphasis after opening punctuation is a valid
+    // left-flanking delimiter run.
+    switch (sc.chPrev) {
+    case '(': case '[': case '{': case '<':
+    case '"': case '\'':
+        return true;
+    default:
+        return false;
+    }
 }
 
 bool IsCompleteStyleRegion(StyleContext &sc, const char *token) {

lexilla/np3_patches/README.md

@@ -8,6 +8,7 @@ This directory contains documentation of all modifications made to the upstream
 |----|------------|-------------|-------------|----------|
 | 001 | `001_StyleContext_MatchNext.patch` | `lexlib/StyleContext.h` | Adds `MatchNext()` and `Match(char,char,char)` overloads | ✅ Yes |
 | 002 | `002_Lexilla_CustomCatalogue.patch` | `src/Lexilla.cxx` | Custom lexer catalogue (NP3 subset only) | ✅ Yes |
+| 003 | `003_LexMarkdown_AtTermStart.patch` | `lexers/LexMarkdown.cxx` | `AtTermStart` accepts opening punctuation `( [ { < " '` so `` (`x`) `` highlights as code | ✅ Yes |
 
 ---
 
@@ -36,6 +37,22 @@ bool MatchNext(char ch0, char ch1, char ch2) const noexcept;
 
 ---
 
+### 003: LexMarkdown `AtTermStart` accepts opening punctuation
+
+**File:** `lexers/LexMarkdown.cxx`
+**Status:** Local fix; candidate for upstream submission. See
+`003_LexMarkdown_AtTermStart.md` for the full write-up.
+
+Stock Lexilla only opens inline spans (code, strong, emphasis,
+strikeout) when the preceding character is whitespace, so
+`` (`Hello`) `` is rendered as plain text. The patch extends
+`AtTermStart` to additionally accept `(`, `[`, `{`, `<`, `"`, `'`.
+
+Visual smoke-test: open
+`test/test_files/StyleLexers/styleLexMARKDOWN/README.md` after build.
+
+---
+
 ### 002: Custom Lexer Catalogue
 
 **File:** `src/Lexilla.cxx`  
@@ -69,7 +86,9 @@ When upgrading Lexilla to a new version:
 lexilla/np3_patches/
 ├── README.md                           # This file
 ├── 001_StyleContext_MatchNext.patch    # StyleContext extensions
-└── 002_Lexilla_CustomCatalogue.patch   # Custom lexer catalogue diff
+├── 002_Lexilla_CustomCatalogue.patch   # Custom lexer catalogue diff
+├── 003_LexMarkdown_AtTermStart.patch   # Markdown: open inline spans after ( [ { < " '
+└── 003_LexMarkdown_AtTermStart.md      # Patch 003 write-up
 ```
 
 ---

test/test_files/StyleLexers/styleLexMARKDOWN/README.md

@@ -87,4 +87,41 @@ During development time the strings in the code are presented to the user. If th
   break existing clients using TypeScript 1.8.x.
 
 ## LICENSE
-[MIT](LICENSE)
+[MIT](LICENSE)
+
+## NP3 Patch 003 — inline spans adjacent to opening punctuation
+
+These lines exercise `AtTermStart` accepting `( [ { < " '`. Every
+backtick/asterisk/underscore/tilde region below MUST render in its
+inline-span style (code / strong / em / strikeout), not as plain text.
+
+Inline code immediately after openers:
+
+- parenthesis: (`Hello`) and (`x` + `y`)
+- square brackets: [`Hello`]
+- curly braces: {`Hello`}
+- angle brackets: <`Hello`>
+- double quote: "`Hello`"
+- single quote: '`Hello`'
+
+Multi-backtick code spans (uses `AtTermStart` directly):
+
+- (``a `b` c``) and [``a `b` c``]
+
+Strong, emphasis, strikeout after the same openers:
+
+- (**bold**) [**bold**] {**bold**} <**bold**> "**bold**" '**bold**'
+- (__bold__) [__bold__] {__bold__}
+- (*em*) [*em*] {*em*} <*em*> "*em*" '*em*'
+- (_em_) [_em_] {_em_}
+- (~~struck~~) [~~struck~~] {~~struck~~}
+
+Regression checks — these should still NOT be styled as inline spans
+(word-adjacent delimiters are intentionally rejected):
+
+- foo`bar`baz  (no code span — `chPrev='o'`)
+- foo*bar*baz  (no emphasis — `chPrev='o'`)
+
+Whitespace-adjacent baseline (must still work):
+
+- a `code` span, a **strong** span, an *em* span, a ~~struck~~ span.