/usr/share/highlight/langDefs/xpp.lang is in highlight-common 3.41-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | Description="SuperX++"
Keywords={
{ Id=1,
Regex=[[<!?\/?\w+>?|>]],
},
{ Id=2,
Regex=[[([-\w]+)="]],
},
{ Id=3,
Regex=[[\&\#?\w+;]],
},
{ Id=4,
List={"bool", "date", "double", "float", "int", "long", "short", "string", "void"},
},
}
Strings={
Delimiter=[["]],
}
IgnoreCase=false
|