def make_chunk(x):
if hasattr(x, 'match_and_replace'): # ideally: if isinstance(x, Chunk):
return x
elif is_listlike(x):
return Chunk(old=x, new=[[x]])
else:
return Chunk(old=[x], new=[[x]])
def make_substitution(elem, env):
# Encloses its answer in a list, no matter what. This enables a .subst()
# method to transform a single item into multiple items.
if hasattr(elem, 'subst'):
return elem.subst(env)
elif is_listlike(elem):
return [flatten(make_substitution(e, env) for e in elem)]
else:
return [elem]
