Add support for escaped whitespace characters

src/drv.pegjs

@@ -26,9 +26,21 @@ string
 	= '"' chars:stringCharacter* '"' { return chars.join(""); }
 
 stringCharacter
-	= !('"' / "\\") char:. { return char; }  // Prefer a non-backslash character...
-	/ stringEscapedQuote { return '"'; }     // ... then an escaped quotation mark...
-	/ !('"') char:. { return char; }         // ... and finally any other character that doesn't terminate the string.
+	= !('"' / "\\") char:. { return char; }        // Prefer a non-backslash character...
+	/ stringEscapedQuote { return '"'; }           // ... then an escaped quotation mark...
+	/ stringEscapedNewline{ return "\n"; }         // ... then various escaped whitespace characters...
+	/ stringEscapedCarriageReturn{ return "\r"; }
+	/ stringEscapedTab{ return "\t"; }
+	/ !('"') char:. { return char; }               // ... and finally any other character that doesn't terminate the string.
 
 stringEscapedQuote
 	= '\\"'
+
+stringEscapedNewline
+	= '\\n'
+
+stringEscapedCarriageReturn
+	= '\\r'
+
+stringEscapedTab
+	= '\\t'