---input---
? 7 * 52;
=> 364
? define variable *your-variable* = $foo;
? begin
   let yours = "apple";
   let mine = yours;
   mine == yours;
 end;
=> #t

---tokens---
'?'           Generic.Prompt
' '           Text
'7'           Literal.Number.Integer
' '           Text
'*'           Operator
' '           Text
'52'          Literal.Number.Integer
';'           Punctuation
'\n'          Text

'=> 364\n'    Generic.Output

'?'           Generic.Prompt
' '           Text
'define'      Keyword
' '           Text
'variable'    Name.Builtin
' '           Text
'*your-variable*' Name.Variable.Global
' '           Text
'='           Operator
' '           Text
'$foo'        Name.Constant
';'           Punctuation
'\n'          Text

'?'           Generic.Prompt
' '           Text
'begin'       Keyword
'\n'          Text

' '           Generic.Prompt
'  '          Text
'let'         Keyword
' '           Text
'yours'       Name
' '           Text
'='           Operator
' '           Text
'"'           Literal.String
'apple'       Literal.String
'"'           Literal.String
';'           Punctuation
'\n'          Text

' '           Generic.Prompt
'  '          Text
'let'         Keyword
' '           Text
'mine'        Name
' '           Text
'='           Operator
' '           Text
'yours'       Name
';'           Punctuation
'\n'          Text

' '           Generic.Prompt
'  '          Text
'mine'        Name
' '           Text
'=='          Operator
' '           Text
'yours'       Name
';'           Punctuation
'\n'          Text

' '           Generic.Prompt
'end'         Keyword
';'           Punctuation
'\n'          Text

'=> #t\n'     Generic.Output