From ba72e6123d3b396e27c7079aaaa35f29160f44d0 Mon Sep 17 00:00:00 2001
From: ike709 <ike709@github.com>
Date: Tue, 26 Nov 2024 20:05:36 -0600
Subject: [PATCH] Support `@(XYZ)` raw strings

---
 .../Expression/String/raw2.dm                 |  0
 .../DMPreprocessor/DMPreprocessorLexer.cs     | 70 ++++++++++++++++++-
 2 files changed, 67 insertions(+), 3 deletions(-)
 rename Content.Tests/DMProject/{Broken Tests => Tests}/Expression/String/raw2.dm (100%)

diff --git a/Content.Tests/DMProject/Broken Tests/Expression/String/raw2.dm b/Content.Tests/DMProject/Tests/Expression/String/raw2.dm
similarity index 100%
rename from Content.Tests/DMProject/Broken Tests/Expression/String/raw2.dm
rename to Content.Tests/DMProject/Tests/Expression/String/raw2.dm
diff --git a/DMCompiler/Compiler/DMPreprocessor/DMPreprocessorLexer.cs b/DMCompiler/Compiler/DMPreprocessor/DMPreprocessorLexer.cs
index 83a3a3a403..154b9cb3b1 100644
--- a/DMCompiler/Compiler/DMPreprocessor/DMPreprocessorLexer.cs
+++ b/DMCompiler/Compiler/DMPreprocessor/DMPreprocessorLexer.cs
@@ -301,12 +301,31 @@ public Token NextToken(bool ignoreWhitespace = false) {
             }
             case '@': { //Raw string
                 char delimiter = Advance();
+                var startLoc = CurrentLocation();
+
+                // @(XYZ) where XYZ is the delimiter
+                string complexDelimiter = string.Empty;
+                if (delimiter == '(') {
+                    Advance();
+                    while (GetCurrent() != ')') {
+                        if (AtEndOfSource()) {
+                            _compiler.Emit(WarningCode.BadExpression, startLoc,
+                                "Unterminated string delimiter");
+                            break;
+                        }
+
+                        complexDelimiter += GetCurrent();
+                        Advance();
+                    }
+                }
 
                 TokenTextBuilder.Clear();
                 TokenTextBuilder.Append('@');
                 TokenTextBuilder.Append(delimiter);
 
+                bool isComplex = complexDelimiter != string.Empty;
                 bool isLong = false;
+
                 c = Advance();
                 if (delimiter == '{') {
                     TokenTextBuilder.Append(c);
@@ -314,7 +333,33 @@ public Token NextToken(bool ignoreWhitespace = false) {
                     if (c == '"') isLong = true;
                 }
 
-                if (isLong) {
+                if (isComplex) {
+                    TokenTextBuilder.Append(complexDelimiter);
+                    TokenTextBuilder.Append(')');
+
+                    // Ignore a newline immediately after @(complexDelimiter)
+                    if (c == '\r') c = Advance();
+                    if (c == '\n') c = Advance();
+
+                    var delimIdx = 0;
+                    do {
+                        TokenTextBuilder.Append(c);
+                        if (GetCurrent() == complexDelimiter[delimIdx]) delimIdx++;
+                        if (delimIdx + 1 == complexDelimiter.Length) {
+                            TokenTextBuilder.Remove(TokenTextBuilder.Length - delimIdx, complexDelimiter.Length - 1);
+                            break;
+                        }
+
+                        c = Advance();
+                    } while (!AtEndOfSource());
+
+                    if (AtEndOfSource()) {
+                        _compiler.Emit(WarningCode.BadExpression, startLoc,
+                            "Unterminated string delimiter");
+                    }
+
+                    TokenTextBuilder.Append(complexDelimiter);
+                } else if (isLong) {
                     bool nextCharCanTerm = false;
 
                     Advance();
@@ -335,6 +380,11 @@ public Token NextToken(bool ignoreWhitespace = false) {
                         if (c == '"')
                             nextCharCanTerm = true;
                     } while (!AtEndOfSource());
+
+                    if (AtEndOfSource()) {
+                        _compiler.Emit(WarningCode.BadExpression, startLoc,
+                            "Unterminated string delimiter");
+                    }
                 } else {
                     while (c != delimiter && !AtLineEnd() && !AtEndOfSource()) {
                         TokenTextBuilder.Append(c);
@@ -342,14 +392,24 @@ public Token NextToken(bool ignoreWhitespace = false) {
                     }
                 }
 
-                TokenTextBuilder.Append(c);
+                if (isComplex) Advance();
+                else TokenTextBuilder.Append(c);
+
                 if (!HandleLineEnd())
                     Advance();
 
                 string text = TokenTextBuilder.ToString();
                 string value;
 
-                if (isLong) {
+                if (isComplex) {
+                    // Complex strings need to strip @(complexDelimiter) and a potential final newline. Newline after @(complexDelimiter) is already handled
+                    var trimEnd = complexDelimiter.Length;
+                    if (TokenTextBuilder[^(complexDelimiter.Length + 1)] == '\n') trimEnd += 1;
+                    if (TokenTextBuilder[^(complexDelimiter.Length + 2)] == '\r') trimEnd += 1;
+                    var trimStart = 3 + complexDelimiter.Length;
+                    value = TokenTextBuilder.ToString(trimStart, TokenTextBuilder.Length - (trimStart + trimEnd));
+                }
+                else if (isLong) {
                     // Long strings ignore a newline immediately after the @{" and before the "}
                     if (TokenTextBuilder[3] == '\n')
                         TokenTextBuilder.Remove(3, 1);
@@ -639,6 +699,10 @@ private char GetCurrent() {
         return _current;
     }
 
+    private Location CurrentLocation() {
+        return new Location(File, _previousLine, _previousColumn, _isDMStandard);
+    }
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private char Advance() {
         int value = _source.Read();