From f8733b1f75de27ee2da04d60aed81c6048afd296 Mon Sep 17 00:00:00 2001
From: Falco Peijnenburg <falco.peijnenburg@channable.com>
Date: Sat, 15 Apr 2023 12:26:24 +0200
Subject: [PATCH] Fix lex error on string like "\z"

---
 src/GLua/Lexer.hs   | 9 ++++++---
 src/GLua/PSLexer.hs | 8 ++++++--
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/GLua/Lexer.hs b/src/GLua/Lexer.hs
index a4b00a1..5063f6c 100644
--- a/src/GLua/Lexer.hs
+++ b/src/GLua/Lexer.hs
@@ -40,10 +40,13 @@ import Text.ParserCombinators.UU.BasicInstances
 -- | String parser that maintains positions.
 type LParser a = P (Str Char String LineColPos) a
 
--- | Whitespace parser.
+-- | Whitespace parser that requires at least one whitespace character
 parseWhitespace :: LParser String
 parseWhitespace = pSome $ pSatisfy (`elem` " \r\n\t") (Insertion "Whitespace" ' ' 5)
-    --MToken <$> pPos <*> (Whitespace <$> pMunch (`elem` " \r\n\t"))
+
+-- | Whitespace parser that requires 0 or more whitespace characters
+parseOptionalWhitespace :: LParser String
+parseOptionalWhitespace = pMany $ pSatisfy (`elem` " \r\n\t") (Insertion "Whitespace" ' ' 5)
 
 -- | Blanco parser. Parses anything. Used in parsing comments.
 parseAnyChar :: LParser Char
@@ -148,7 +151,7 @@ parseLineString c = pSym c *> innerString
                       (:) <$> pNoNewline <*> innerString -- the next character in the string
 
         escapeSequence :: LParser String
-        escapeSequence = (:) <$> pSym 'z' <*> parseWhitespace <<|> (:[]) <$> parseAnyChar
+        escapeSequence = (:) <$> pSym 'z' <*> parseOptionalWhitespace <<|> (:[]) <$> parseAnyChar
 
         pNoNewline :: LParser Char
         pNoNewline = pSatisfy (/= '\n') (Insertion "Anything but a newline" c 5)
diff --git a/src/GLua/PSLexer.hs b/src/GLua/PSLexer.hs
index ddb97d1..413e5b4 100644
--- a/src/GLua/PSLexer.hs
+++ b/src/GLua/PSLexer.hs
@@ -90,16 +90,20 @@ cBetween c left right = c >= left && c <= right
 pUntilEnd :: Parser String
 pUntilEnd = manyTill anyChar (lookAhead (endOfLine <|> const '\n' <$> eof))
 
--- | Whitespace parser.
+-- | Whitespace parser that requires at least one whitespace character
 parseWhitespace :: Parser String
 parseWhitespace = many1 space <?> "whitespace"
 
+-- | Whitespace parser that requires 0 or more whitespace characters
+parseOptionalWhitespace :: Parser String
+parseOptionalWhitespace = many space <?> "whitespace"
+
 -- | An escaped character of a single line string
 -- Takes the delimiter of the string as parameter
 escapedStringChar :: Char -> Parser String
 escapedStringChar delim = (\escaped -> '\\' : escaped) <$ char '\\' <*> escapedChar <|> (:[]) <$> noneOf ['\n', delim]
     where
-        escapedChar = (:) <$> char 'z' <*> parseWhitespace <|> (:[]) <$> anyChar
+        escapedChar = (:) <$> char 'z' <*> parseOptionalWhitespace <|> (:[]) <$> anyChar
 
 -- | The start of a nested string
 -- Returns the amount of =-signs at the start of the nested string