Feature request: more flexible layer mapping

[klayoutmatthias]

GDS and other readers allow mapping or selecting the layers to be read. This specification includes intervals, so this layer selection is allowed:

1-10/0

which will select layers 1 to 10, datatype 0.

However, if such a specification is used, all shapes are mapped to "1/0". To maintain the original layer, the mapping has to be split. This is hardly possible for arbitrary inputs such as "all datatypes of layer 1".

To allow such a request, it is suggested to extend the "target" feature allowing wildcards. In this case

1-10/0 : */*
# or
1-10/0 : */0

which is supposed to preserve the original layer numbers.

Some more suggestions

# read all data types of layer 1:
1/* : */*
# map layer 1 and 2 to 1 and bump the datatypes of layer 2
1/* : 1/*
2/* : 1/*+1000