From 4638ff004a15f304271d67859be999e27483f1eb Mon Sep 17 00:00:00 2001
From: doug1234 <doug_ayers@yahoo.com>
Date: Mon, 20 Feb 2023 10:18:06 -0500
Subject: [PATCH 1/2] Added new single and double quote tests for escape
 characters.

---
 test/lua/literals/_doublequote.lua | 3 +++
 test/lua/literals/_singlequote.lua | 3 +++
 test/lua/literals/doublequote.lua  | 3 +++
 test/lua/literals/singlequote.lua  | 3 +++
 4 files changed, 12 insertions(+)

diff --git a/test/lua/literals/_doublequote.lua b/test/lua/literals/_doublequote.lua
index 2290916..f800c84 100644
--- a/test/lua/literals/_doublequote.lua
+++ b/test/lua/literals/_doublequote.lua
@@ -5,3 +5,6 @@ local bar = '"'
 local foobar = '\\\\"'
 local kek = '\\'
 local topkek = 'a\\'
+local nothing = ''
+local dir = 'C:\\\'Some Dir\'\\'
+local escapedQuote = '\''
diff --git a/test/lua/literals/_singlequote.lua b/test/lua/literals/_singlequote.lua
index a101ab6..fbf0027 100644
--- a/test/lua/literals/_singlequote.lua
+++ b/test/lua/literals/_singlequote.lua
@@ -5,3 +5,6 @@ local foo = "'"
 local foobar = "\\\\'"
 local kek = "\\"
 local topkek = "a\\"
+local nothing = ""
+local dir = "C:\\\"Some Dir\"\\"
+local escapedQuote = "\""
diff --git a/test/lua/literals/doublequote.lua b/test/lua/literals/doublequote.lua
index 7644216..497f335 100644
--- a/test/lua/literals/doublequote.lua
+++ b/test/lua/literals/doublequote.lua
@@ -5,3 +5,6 @@ local bar = "\""
 local foobar = "\\\\\""
 local kek = "\\"
 local topkek = "a\\"
+local nothing = ""
+local dir = "C:\\'Some Dir'\\"
+local escapedQuote = "\'"
diff --git a/test/lua/literals/singlequote.lua b/test/lua/literals/singlequote.lua
index 730e90d..71d9589 100644
--- a/test/lua/literals/singlequote.lua
+++ b/test/lua/literals/singlequote.lua
@@ -5,3 +5,6 @@ local foo = '\''
 local foobar = '\\\\\''
 local kek = '\\'
 local topkek = 'a\\'
+local nothing = ''
+local dir = 'C:\\"Some Dir"\\'
+local escapedQuote = '\"'

From d7264fbd4b8abe83cde8e8e9309b0ad513c53637 Mon Sep 17 00:00:00 2001
From: doug1234 <doug_ayers@yahoo.com>
Date: Mon, 20 Feb 2023 11:15:37 -0500
Subject: [PATCH 2/2] Fix incorrect escape character handling for issue #274. 
 Added a couple more tests.

---
 src/visitor/FormatVisitor.cpp      | 45 ++++++++++++++++++++----------
 test/lua/literals/_doublequote.lua |  2 ++
 test/lua/literals/_singlequote.lua |  2 ++
 test/lua/literals/doublequote.lua  |  2 ++
 test/lua/literals/singlequote.lua  |  2 ++
 5 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/src/visitor/FormatVisitor.cpp b/src/visitor/FormatVisitor.cpp
index 044a050..5b8fbf5 100644
--- a/src/visitor/FormatVisitor.cpp
+++ b/src/visitor/FormatVisitor.cpp
@@ -250,23 +250,38 @@ antlrcpp::Any FormatVisitor::visitString(LuaParser::StringContext* ctx) {
             assert(0);
     }
 
-    std::string oldstr = ctx->getText();
-    std::string newstr;
-
-    std::regex re_single("'", std::regex_constants::extended);
-    std::regex re_double("\"", std::regex_constants::extended);
-    std::regex re_escapedsingle("\\\\'", std::regex_constants::extended);
-    std::regex re_escapeddouble("\\\\\"", std::regex_constants::extended);
-
-    if (quote == '\"') {
-        regex_replace(std::back_inserter(newstr), oldstr.begin() + 1, oldstr.end() - 1, re_escapedsingle, "'");
-        newstr = regex_replace(newstr, re_double, "\\\"");
-    } else {
-        regex_replace(std::back_inserter(newstr), oldstr.begin() + 1, oldstr.end() - 1, re_single, "\\'");
-        newstr = regex_replace(newstr, re_escapeddouble, "\"");
+    //Switch the type of quote
+    std::string newstr = ctx->getText();
+    newstr.front() = quote;    
+    newstr.back() = quote;
+    bool escaped = false;  //Is the current character in the sequence escaped
+    const char oldChar = quote == '\'' ? '"' : '\'';  
+    auto itr = ++newstr.begin();
+    auto itrStop = --newstr.end();
+    while (itr != itrStop) {
+        if (*itr == '\\') {
+            escaped = !escaped;  //If the character isn't currently escaped, the next one will be escaped
+        } else {
+            if (*itr == quote) {
+                // Add the escape character before the non escaped old character
+                if (!escaped) {
+                    itr = newstr.insert(itr, '\\');
+                    ++itr;  // Extra incriment to get back to the previous character
+                    itrStop = --newstr.end();
+                }
+            } else if (*itr == oldChar) {
+                // Remove the escape before the previously escaped old character
+                if (escaped) {
+                    itr = newstr.erase(--itr);
+                    itrStop = --newstr.end();
+                }        
+            }
+            escaped = false;
+        }
+        ++itr;
     }
 
-    cur_writer() << quote + newstr + quote;
+    cur_writer() << newstr;
     return nullptr;
 }
 
diff --git a/test/lua/literals/_doublequote.lua b/test/lua/literals/_doublequote.lua
index f800c84..b7bb590 100644
--- a/test/lua/literals/_doublequote.lua
+++ b/test/lua/literals/_doublequote.lua
@@ -8,3 +8,5 @@ local topkek = 'a\\'
 local nothing = ''
 local dir = 'C:\\\'Some Dir\'\\'
 local escapedQuote = '\''
+local manyEscape1 = '\\\\\\\\\''
+local manyEscape2 = '\\\\\\\\\''
diff --git a/test/lua/literals/_singlequote.lua b/test/lua/literals/_singlequote.lua
index fbf0027..69e04fb 100644
--- a/test/lua/literals/_singlequote.lua
+++ b/test/lua/literals/_singlequote.lua
@@ -8,3 +8,5 @@ local topkek = "a\\"
 local nothing = ""
 local dir = "C:\\\"Some Dir\"\\"
 local escapedQuote = "\""
+local manyEscape1 = "\\\\\\\\\""
+local manyEscape2 = "\\\\\\\\\""
diff --git a/test/lua/literals/doublequote.lua b/test/lua/literals/doublequote.lua
index 497f335..3a8dc8c 100644
--- a/test/lua/literals/doublequote.lua
+++ b/test/lua/literals/doublequote.lua
@@ -8,3 +8,5 @@ local topkek = "a\\"
 local nothing = ""
 local dir = "C:\\'Some Dir'\\"
 local escapedQuote = "\'"
+local manyEscape1 = "\\\\\\\\'"
+local manyEscape2 = "\\\\\\\\\'"
diff --git a/test/lua/literals/singlequote.lua b/test/lua/literals/singlequote.lua
index 71d9589..32115d6 100644
--- a/test/lua/literals/singlequote.lua
+++ b/test/lua/literals/singlequote.lua
@@ -8,3 +8,5 @@ local topkek = 'a\\'
 local nothing = ''
 local dir = 'C:\\"Some Dir"\\'
 local escapedQuote = '\"'
+local manyEscape1 = '\\\\\\\\"'
+local manyEscape2 = '\\\\\\\\\"'