---input---
@{:ant @{:legs 6} :bee @{:legs 6} :cheetah @{:legs 4}}

---tokens---
'@{'          Punctuation
':ant'        Name.Constant
' '           Text.Whitespace
'@{'          Punctuation
':legs'       Name.Constant
' '           Text.Whitespace
'6'           Literal.Number.Float
'}'           Punctuation
' '           Text.Whitespace
':bee'        Name.Constant
' '           Text.Whitespace
'@{'          Punctuation
':legs'       Name.Constant
' '           Text.Whitespace
'6'           Literal.Number.Float
'}'           Punctuation
' '           Text.Whitespace
':cheetah'    Name.Constant
' '           Text.Whitespace
'@{'          Punctuation
':legs'       Name.Constant
' '           Text.Whitespace
'4'           Literal.Number.Float
'}'           Punctuation
'}'           Punctuation
'\n'          Text.Whitespace