opensourcegames/code/utils/osg_parse.py

140 lines
3.7 KiB
Python

"""
"""
from functools import partial
import lark
from utils import utils, constants as c
class ListingTransformer(lark.Transformer):
"""
Transforms content parsed by grammar_listing.lark further.
Used for the developer and inspirations list.
"""
def unquoted_value(self, x):
return x[0].value
def quoted_value(self, x):
return x[0].value[1:-1] # remove quotation marks
def property(self, x):
"""
The key of a property will be converted to lower case and the value part is the second part
:param x:
:return:
"""
return x[0], x[1:]
def name(self, x):
"""
The name part is treated as a property with key "Name"
:param x:
:return:
"""
return 'Name', x[0].value
def entry(self, x):
"""
All (key, value) tuples are inserted into a dictionary.
:param x:
:return:
"""
d = {}
for key, value in x:
if key in d:
raise RuntimeError('Key in entry appears twice')
d[key] = value
return d
def start(self, x):
return x
# transformer
class EntryTransformer(lark.Transformer):
def unquoted_value(self, x):
return x[0].value
def quoted_value(self, x):
return x[0].value[1:-1] # remove quotation marks
def property(self, x):
"""
The key of a property will be converted to lower case and the value part is the second part
:param x:
:return:
"""
return x[0], x[1:]
def title(self, x):
return 'Title', x[0].value
def note(self, x):
"""
Optional
:param x:
:return:
"""
if not x:
raise lark.Discard
return 'Note', ''.join((x.value for x in x))
def building(self, x):
d = {}
for key, value in x:
if key in d:
raise RuntimeError('Key in entry appears twice')
d[key] = value
return 'Building', d
def start(self, x):
# we do the essential fields and valid fields checks right here
fields = [x[0] for x in x]
# check for essential fields
for field in c.essential_fields:
if field not in fields:
raise RuntimeError('Essential field "{}" is missing'.format(field))
# check for valid fields (in that order)
index = 0
for field in fields:
while index < len(c.valid_fields) and field != c.valid_fields[index]:
index += 1
if index == len(c.valid_fields):
raise RuntimeError('Field "{}" either not valid or in wrong order'.format(field))
d = {}
for key, value in x:
if key in d:
raise RuntimeError('Key in entry appears twice')
d[key] = value
return d
def parse(parser, transformer, content):
tree = parser.parse(content)
value = transformer.transform(tree)
return value
def create(grammar, Transformer):
parser = lark.Lark(grammar, debug=False, parser='lalr')
transformer = Transformer()
return partial(parse, parser, transformer)
def read_and_parse(content_file: str, grammar_file: str, Transformer: lark.Transformer):
"""
Reads a content file and a grammar file and parses the content with the grammar following by
transforming the parsed output and returning the transformed result.
:param content_file:
:param grammar_file:
:param transformer:
:return:
"""
grammar = utils.read_text(grammar_file)
parse = create(grammar, Transformer)
content = utils.read_text(content_file)
return parse(content)