templater: add inheritance support to style maps
We can now specify a base map file:
__base__ = path/to/map/file
That map file will be read and used to populate unset elements of the
current map. Unlike using %include, elements in the inherited class
will be read relative to that path.
This makes it much easier to make custom local tweaks to a style.
from __future__ import absolute_import, print_function
import sys
globalvars = {}
lines = sys.stdin.readlines()
while lines:
l = lines.pop(0)
if l.startswith('SALT'):
print(l[:-1])
elif l.startswith('>>> '):
snippet = l[4:]
while lines and lines[0].startswith('... '):
l = lines.pop(0)
snippet += l[4:]
c = compile(snippet, '<heredoc>', 'single')
try:
exec(c, globalvars)
except Exception as inst:
print(repr(inst))