---input---
string woof = "woof";
string escaped = "a \"woof\" and \'woof\',a \\, and a \tand not a \b...\n";
let s = "

---tokens---
'string'      Keyword.Type
' '           Text.Whitespace
'woof'        Name
' '           Text.Whitespace
'='           Punctuation
' '           Text.Whitespace
'"'           Literal.String
'woof'        Literal.String
'"'           Literal.String
';'           Punctuation
'\n'          Text.Whitespace

'string'      Keyword.Type
' '           Text.Whitespace
'escaped'     Name
' '           Text.Whitespace
'='           Punctuation
' '           Text.Whitespace
'"'           Literal.String
'a '          Literal.String
'\\"'         Literal.String.Escape
'woof'        Literal.String
'\\"'         Literal.String.Escape
' and '       Literal.String
"\\'"         Literal.String.Escape
'woof'        Literal.String
"\\'"         Literal.String.Escape
',a '         Literal.String
'\\\\'        Literal.String.Escape
', and a '    Literal.String
'\\t'         Literal.String.Escape
'and not a '  Literal.String
'\\'          Error
'b...'        Literal.String
'\\n'         Literal.String.Escape
'"'           Literal.String
';'           Punctuation
'\n'          Text.Whitespace

'let'         Keyword
' '           Text.Whitespace
's'           Name
' '           Text.Whitespace
'='           Punctuation
' '           Text.Whitespace
'"'           Literal.String
'\n'          Literal.String
