---input---
delta(cpu_temp_celsius{host="zeus"}[2h])

---tokens---
'delta'       Keyword.Reserved
'('           Operator
'cpu_temp_celsius' Name.Variable
'{'           Punctuation
'host'        Name.Label
'='           Operator
'"'           Punctuation
'zeus'        Literal.String
'"'           Punctuation
'}'           Punctuation
'['           Punctuation
'2h'          Literal.String
']'           Punctuation
')'           Operator
'\n'          Text.Whitespace