---input---
"hello world"

"hello ${ { a = "world"; }.a }"

"1 2 ${toString 3}"

"${pkgs.bash}/bin/sh"

true, false, null, 123, 3.141

-1

/etc
./foo.png
~/.config

<nixpkgs>

''
  multi
   line
    string
''

''
  multi
   ${value}
    string
''

---tokens---
'"'           Literal.String.Double
'hello world' Literal.String.Double
'"'           Literal.String.Double
'\n\n'        Text

'"'           Literal.String.Double
'hello '      Literal.String.Double
'${'          Literal.String.Interpol
' '           Text
'{'           Punctuation
' '           Text
'a'           Literal.String.Symbol
' '           Text
'='           Operator
' '           Text
'"'           Literal.String.Double
'world'       Literal.String.Double
'"'           Literal.String.Double
';'           Punctuation
' '           Text
'}'           Punctuation
'.'           Operator
'a'           Text
' '           Text
'}'           Literal.String.Interpol
'"'           Literal.String.Double
'\n\n'        Text

'"'           Literal.String.Double
'1 2 '        Literal.String.Double
'${'          Literal.String.Interpol
'toString'    Name.Builtin
' '           Text
'3'           Literal.Number.Integer
'}'           Literal.String.Interpol
'"'           Literal.String.Double
'\n\n'        Text

'"'           Literal.String.Double
'${'          Literal.String.Interpol
'pkgs'        Text
'.'           Operator
'bash'        Text
'}'           Literal.String.Interpol
'/bin/sh'     Literal.String.Double
'"'           Literal.String.Double
'\n\n'        Text

'true'        Name.Constant
','           Punctuation
' '           Text
'false'       Name.Constant
','           Punctuation
' '           Text
'null'        Name.Constant
','           Punctuation
' '           Text
'123'         Literal.Number.Integer
','           Punctuation
' '           Text
'3.141'       Literal.Number.Float
'\n\n'        Text

'-1'          Literal.Number.Integer
'\n\n'        Text

'/etc'        Literal
'\n'          Text

'./foo.png'   Literal
'\n'          Text

'~/.config'   Literal
'\n\n'        Text

'<nixpkgs>'   Literal
'\n\n'        Text

"''"          Literal.String.Multiline
'\n  multi\n   line\n    string\n' Literal.String.Multiline

"''"          Literal.String.Multiline
'\n\n'        Text

"''"          Literal.String.Multiline
'\n  multi\n   ' Literal.String.Multiline
'${'          Literal.String.Interpol
'value'       Text
'}'           Literal.String.Interpol
'\n    string\n' Literal.String.Multiline

"''"          Literal.String.Multiline
'\n'          Text