---input---
if 1 + 1 == 2 then "yes!" else "no!"

assert 1 + 1 == 2; "yes!"

let x = "foo"; y = "bar"; in x + y

with builtins; head [ 1 2 3 ]

---tokens---
'if'          Keyword
' '           Text
'1'           Literal.Number.Integer
' '           Text
'+'           Operator
' '           Text
'1'           Literal.Number.Integer
' '           Text
'=='          Operator
' '           Text
'2'           Literal.Number.Integer
' '           Text
'then'        Keyword
' '           Text
'"'           Literal.String.Double
'yes!'        Literal.String.Double
'"'           Literal.String.Double
' '           Text
'else'        Keyword
' '           Text
'"'           Literal.String.Double
'no!'         Literal.String.Double
'"'           Literal.String.Double
'\n\n'        Text

'assert'      Keyword
' '           Text
'1'           Literal.Number.Integer
' '           Text
'+'           Operator
' '           Text
'1'           Literal.Number.Integer
' '           Text
'=='          Operator
' '           Text
'2'           Literal.Number.Integer
';'           Punctuation
' '           Text
'"'           Literal.String.Double
'yes!'        Literal.String.Double
'"'           Literal.String.Double
'\n\n'        Text

'let'         Keyword
' '           Text
'x'           Literal.String.Symbol
' '           Text
'='           Operator
' '           Text
'"'           Literal.String.Double
'foo'         Literal.String.Double
'"'           Literal.String.Double
';'           Punctuation
' '           Text
'y'           Literal.String.Symbol
' '           Text
'='           Operator
' '           Text
'"'           Literal.String.Double
'bar'         Literal.String.Double
'"'           Literal.String.Double
';'           Punctuation
' '           Text
'in'          Keyword
' '           Text
'x'           Text
' '           Text
'+'           Operator
' '           Text
'y'           Text
'\n\n'        Text

'with'        Keyword
' '           Text
'builtins'    Name.Builtin
';'           Punctuation
' '           Text
'head'        Text
' '           Text
'['           Punctuation
' '           Text
'1'           Literal.Number.Integer
' '           Text
'2'           Literal.Number.Integer
' '           Text
'3'           Literal.Number.Integer
' '           Text
']'           Punctuation
'\n'          Text