From 639f9cb02183d1bdf17f13a4045320f007c35020 Mon Sep 17 00:00:00 2001
From: laniakea64 <laniakea64@users.noreply.github.com>
Date: Mon, 30 Sep 2024 20:03:17 -0400
Subject: [PATCH] Initial support for `\u{...}` escape sequences

---
 syntax/just.vim              | 33 +++++++++++++++++++--------------
 tests/cases/expressions.html | 10 ++++++++++
 tests/cases/expressions.just | 10 ++++++++++
 3 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/syntax/just.vim b/syntax/just.vim
index c0d5f04..08eb187 100644
--- a/syntax/just.vim
+++ b/syntax/just.vim
@@ -32,8 +32,8 @@ syn region justBacktick start=/`/ end=/`/
 syn region justBacktick start=/```/ end=/```/
 syn region justRawString start=/'/ end=/'/
 syn region justRawString start=/'''/ end=/'''/
-syn region justString start=/"/ skip=/\\\\\|\\"/ end=/"/ contains=justStringEscapeSequence
-syn region justString start=/"""/ skip=/\\\\\|\\"/ end=/"""/ contains=justStringEscapeSequence
+syn region justString start=/"/ skip=/\\\\\|\\"/ end=/"/ contains=justStringEscapeSequence,justStringUEscapeSequence
+syn region justString start=/"""/ skip=/\\\\\|\\"/ end=/"""/ contains=justStringEscapeSequence,justStringUEscapeSequence
 
 syn region justShellExpandRawString start=/\v\k@1<!x'/ end=/'/
    \ contains=justShellExpandVarRaw,justDollarEscape
@@ -41,10 +41,10 @@ syn region justShellExpandRawString start=/\v\k@1<!x'''/ end=/'''/
    \ contains=justShellExpandVarRaw,justDollarEscape
 syn region justShellExpandString
    \ start=/\v\k@1<!x"/ skip=/\\\\\|\\"/ end=/"/
-   \ contains=justStringEscapeSequence,justShellExpandVar,justDollarEscape
+   \ contains=justStringEscapeSequence,justStringUEscapeSequence,justShellExpandVar,justDollarEscape
 syn region justShellExpandString
    \ start=/\v\k@1<!x"""/ skip=/\\\\\|\\"/ end=/"""/
-   \ contains=justStringEscapeSequence,justShellExpandVar,justDollarEscape
+   \ contains=justStringEscapeSequence,justStringUEscapeSequence,justShellExpandVar,justDollarEscape
 
 syn cluster justStringLiterals
    \ contains=justRawString,justString,justShellExpandRawString,justShellExpandString
@@ -59,8 +59,8 @@ syn match justRegexReplacement
 
 syn region justRawStrRegexRepl start=/\v'/ end=/'/ contained contains=justRegexCapture,justDollarEscape
 syn region justRawStrRegexRepl start=/\v'''/ end=/'''/ contained contains=justRegexCapture,justDollarEscape
-syn region justStringRegexRepl start=/\v"/ skip=/\\\\\|\\"/ end=/"/ contained contains=justStringEscapeSequence,justRegexCapture,justDollarEscape
-syn region justStringRegexRepl start=/\v"""/ skip=/\\\\\|\\"/ end=/"""/ contained contains=justStringEscapeSequence,justRegexCapture,justDollarEscape
+syn region justStringRegexRepl start=/\v"/ skip=/\\\\\|\\"/ end=/"/ contained contains=justStringEscapeSequence,justStringUEscapeSequence,justRegexCapture,justDollarEscape
+syn region justStringRegexRepl start=/\v"""/ skip=/\\\\\|\\"/ end=/"""/ contained contains=justStringEscapeSequence,justStringUEscapeSequence,justRegexCapture,justDollarEscape
 syn match justRegexCapture '\v\$%(\w+|\{\w+\})' contained
 syn cluster justStringsWithRegexCapture contains=justRawStrRegexRepl,justStringRegexRepl
 
@@ -72,6 +72,7 @@ syn region justStringInShebangBody start=/\v\\@1<!'/ end=/'/ contained contains=
 syn region justStringInShebangBody start=/\v\\@1<!"/ skip=/\v\\@1<!\\"/ end=/"/ contained contains=justInterpolation,@justOtherCurlyBraces,justShebangIndentError
 
 syn match justStringEscapeSequence '\v\\[tnr"\\]' contained
+syn match justStringUEscapeSequence '\v\\u\{[0-9A-Fa-f]{1,6}\}' contained
 
 syn match justAssignmentOperator "\V:=" contained
 
@@ -276,12 +277,15 @@ syn match justOperator "\V/"
 syn keyword justConstant
    \ HEX HEXLOWER HEXUPPER
 
-syn match justShellExpandVarRaw '\v\$%(\{\_[^}]*\}|\w+)' contained contains=justShellExpandRawDefault
-syn match justShellExpandRawDefault '\V:-' contained nextgroup=justShellExpandRawDefaultValue
+syn match justShellExpandVarRaw '\v\$%(\{\_[^}]*\}|\w+)' contained contains=justShellExpandRawDefaultDelimiter
+syn match justShellExpandRawDefaultDelimiter '\V:-' contained nextgroup=justShellExpandRawDefaultValue
 syn match justShellExpandRawDefaultValue '\v\_[^}]*' contained
-syn match justShellExpandVar '\v\$%(\{\_[^}]*\}|%(\w|\\\n\s*)+)' contained contains=justShellExpandDefault,justStringEscapeSequence
-syn match justShellExpandDefault '\V:-' contained nextgroup=justShellExpandDefaultValue
-syn match justShellExpandDefaultValue '\v\_[^}]*' contained contains=justStringEscapeSequence
+syn match justShellExpandVar '\v\$%(\w|\\\n\s*)+' contained
+syn region justShellExpandVar start='\V${' end='}' contains=justShellExpandDefault,justStringEscapeSequence,justStringUEscapeSequence
+syn region justShellExpandDefault
+   \ matchgroup=justShellExpandDefaultDelimiter start='\V:-' end='\v\}@='
+   \ contained
+   \ contains=justStringEscapeSequence,justStringUEscapeSequence
 
 syn match justDollarEscape '\V$$' contained
 
@@ -365,9 +369,9 @@ hi def link justSetKeywords                      Keyword
 hi def link justShebang                          SpecialComment
 hi def link justShebangBody                      Number
 hi def link justShebangIndentError               Error
-hi def link justShellExpandDefault               Operator
-hi def link justShellExpandDefaultValue          Character
-hi def link justShellExpandRawDefault            Operator
+hi def link justShellExpandDefault               Character
+hi def link justShellExpandDefaultDelimiter      Operator
+hi def link justShellExpandRawDefaultDelimiter   Operator
 hi def link justShellExpandRawDefaultValue       Character
 hi def link justShellExpandRawString             String
 hi def link justShellExpandString                String
@@ -379,6 +383,7 @@ hi def link justStringEscapeSequence             Special
 hi def link justStringInShebangBody              String
 hi def link justStringInsideBody                 String
 hi def link justStringRegexRepl                  String
+hi def link justStringUEscapeSequence            Special
 hi def link justUnexport                         Statement
 hi def link justUserDefinedError                 Exception
 hi def link justVariadicPrefix                   Statement
diff --git a/tests/cases/expressions.html b/tests/cases/expressions.html
index 34cd0fc..5aa898b 100644
--- a/tests/cases/expressions.html
+++ b/tests/cases/expressions.html
@@ -54,3 +54,13 @@
 <span class="Type">[private]</span>
 hidden <span class="Operator">:=</span> <span class="String">'foo'</span>
 not_hidden <span class="Operator">:=</span> <span class="String">'-'</span> <span class="Operator">+</span> hidden
+
+u_escape <span class="Operator">:=</span> <span class="String">"test </span><span class="Special">\u{1F916}</span><span class="String"> test"</span>
+u_escape_triple_quoted <span class="Operator">:=</span> <span class="String">"""</span>
+<span class="String">  test</span>
+<span class="String">  </span><span class="Special">\u{1f9Ea}</span>
+<span class="String">  test</span>
+<span class="String">"""</span>
+u_escape_shell_expanded <span class="Operator">:=</span> <span class="String">x"shell </span><span class="PreProc">${FOO</span><span class="Operator">:-</span><span class="Character">(</span><span class="Special">\u{1f41a}</span><span class="Character">)</span><span class="PreProc">}</span><span class="String"> shell"</span>
+u_escape_in_replace_regex <span class="Operator">:=</span> <span class="Function">replace_regex</span>(<span class="String">'foo'</span>, <span class="String">'^.'</span>, <span class="String">"</span><span class="Special">\u{46}</span><span class="String">"</span>)
+not_u_escape <span class="Operator">:=</span> <span class="String">'\u{1F916}'</span>
diff --git a/tests/cases/expressions.just b/tests/cases/expressions.just
index 5ba95b5..9129452 100644
--- a/tests/cases/expressions.just
+++ b/tests/cases/expressions.just
@@ -54,3 +54,13 @@ now_utc := datetime_utc('%Y-%m-%d %H:%M:%S %Z')
 [private]
 hidden := 'foo'
 not_hidden := '-' + hidden
+
+u_escape := "test \u{1F916} test"
+u_escape_triple_quoted := """
+  test
+  \u{1f9Ea}
+  test
+"""
+u_escape_shell_expanded := x"shell ${FOO:-(\u{1f41a})} shell"
+u_escape_in_replace_regex := replace_regex('foo', '^.', "\u{46}")
+not_u_escape := '\u{1F916}'