forked from syndicate-lang/preserves
First steps to schema support for python
This commit is contained in:
parent
5c8bacd759
commit
abe60b3506
|
|
@ -35,7 +35,10 @@ class Float(object):
|
|||
|
||||
class Symbol(object):
|
||||
def __init__(self, name):
|
||||
self.name = name
|
||||
if isinstance(name, Symbol):
|
||||
self.name = name.name
|
||||
else:
|
||||
self.name = name
|
||||
|
||||
def __eq__(self, other):
|
||||
return isinstance(other, Symbol) and self.name == other.name
|
||||
|
|
|
|||
|
|
@ -0,0 +1,355 @@
|
|||
from .preserves import *
|
||||
import pathlib
|
||||
|
||||
AND = Symbol('and')
|
||||
ANY = Symbol('any')
|
||||
ATOM = Symbol('atom')
|
||||
BOOLEAN = Symbol('Boolean')
|
||||
BUNDLE = Symbol('bundle')
|
||||
BYTE_STRING = Symbol('ByteString')
|
||||
DEFINITIONS = Symbol('definitions')
|
||||
DICT = Symbol('dict')
|
||||
DICTOF = Symbol('dictof')
|
||||
DOUBLE = Symbol('Double')
|
||||
EMBEDDED = Symbol('embedded')
|
||||
FLOAT = Symbol('Float')
|
||||
LIT = Symbol('lit')
|
||||
NAMED = Symbol('named')
|
||||
OR = Symbol('or')
|
||||
REC = Symbol('rec')
|
||||
REF = Symbol('ref')
|
||||
SCHEMA = Symbol('schema')
|
||||
SEQOF = Symbol('seqof')
|
||||
SETOF = Symbol('setof')
|
||||
SIGNED_INTEGER = Symbol('SignedInteger')
|
||||
STRING = Symbol('String')
|
||||
SYMBOL = Symbol('Symbol')
|
||||
TUPLE = Symbol('tuple')
|
||||
TUPLE_PREFIX = Symbol('tuplePrefix')
|
||||
VERSION = Symbol('version')
|
||||
|
||||
class SchemaEntity:
|
||||
ROOTNS = None
|
||||
SCHEMA = None
|
||||
MODULE_PATH = None
|
||||
NAME = None
|
||||
|
||||
@classmethod
|
||||
def decode(cls, v):
|
||||
i = cls.try_decode(v)
|
||||
if i is None:
|
||||
raise Exception('Could not decode ' + str(cls))
|
||||
return i
|
||||
|
||||
@classmethod
|
||||
def try_decode(cls, v):
|
||||
raise Exception('Subclass responsibility')
|
||||
|
||||
@classmethod
|
||||
def parse(cls, p, v, args):
|
||||
if p == ANY:
|
||||
return v
|
||||
if p.key == NAMED:
|
||||
i = cls.parse(p[1], v, args)
|
||||
if i is not None: args.append(i)
|
||||
return i
|
||||
if p.key == ATOM:
|
||||
k = p[0]
|
||||
if k == BOOLEAN and isinstance(v, bool): return v
|
||||
if k == FLOAT and isinstance(v, Float): return v
|
||||
if k == DOUBLE and isinstance(v, float): return v
|
||||
if k == SIGNED_INTEGER and isinstance(v, int): return v
|
||||
if k == STRING and isinstance(v, str): return v
|
||||
if k == BYTE_STRING and isinstance(v, bytes): return v
|
||||
if k == SYMBOL and isinstance(v, Symbol): return v
|
||||
return None
|
||||
if p.key == EMBEDDED:
|
||||
return v ## TODO: reconsider representation of embedded values?
|
||||
if p.key == LIT:
|
||||
if v == p[0]: return ()
|
||||
return None
|
||||
if p.key == SEQOF:
|
||||
if not isinstance(v, tuple): return None
|
||||
vv = []
|
||||
for w in v:
|
||||
ww = cls.parse(p[0], w, args)
|
||||
if ww is None: return None
|
||||
vv.append(ww)
|
||||
return vv
|
||||
if p.key == SETOF:
|
||||
if not isinstance(v, set): return None
|
||||
vv = set()
|
||||
for w in v:
|
||||
ww = cls.parse(p[0], w, args)
|
||||
if ww is None: return None
|
||||
vv.add(ww)
|
||||
return vv
|
||||
if p.key == DICTOF:
|
||||
if not isinstance(v, dict): return None
|
||||
dd = {}
|
||||
for (k, w) in v.items():
|
||||
kk = cls.parse(p[0], k, args)
|
||||
if kk is None: return None
|
||||
ww = cls.parse(p[1], w, args)
|
||||
if ww is None: return None
|
||||
dd[kk] = ww
|
||||
return dd
|
||||
if p.key == REF:
|
||||
c = lookup(cls.ROOTNS, cls.MODULE_PATH if len(p[0]) == 0 else p[0], p[1])
|
||||
return c.try_decode(v)
|
||||
if p.key == REC:
|
||||
if not isinstance(v, Record): return None
|
||||
if cls.parse(p[0], v.key, args) is None: return None
|
||||
if cls.parse(p[1], v.fields, args) is None: return None
|
||||
return ()
|
||||
if p.key == TUPLE:
|
||||
if not isinstance(v, tuple): return None
|
||||
if len(v) != len(p[0]): return None
|
||||
i = 0
|
||||
for pp in p[0]:
|
||||
if cls.parse(pp, v[i], args) is None: return None
|
||||
i = i + 1
|
||||
return ()
|
||||
if p.key == TUPLE_PREFIX:
|
||||
if not isinstance(v, tuple): return None
|
||||
if len(v) < len(p[0]): return None
|
||||
i = 0
|
||||
for pp in p[0]:
|
||||
if cls.parse(pp, v[i], args) is None: return None
|
||||
i = i + 1
|
||||
if cls.parse(p[1], v[i:], args) is None: return None
|
||||
return ()
|
||||
if p.key == DICT:
|
||||
if not isinstance(v, dict): return None
|
||||
if len(v) < len(p[0]): return None
|
||||
for (k, pp) in p[0].items():
|
||||
if k not in v: return None
|
||||
if cls.parse(pp, v[k], args) is None: return None
|
||||
return ()
|
||||
raise Exception('Bad schema')
|
||||
|
||||
def _encode(self):
|
||||
raise Exception('Subclass responsibility')
|
||||
|
||||
def __repr__(self):
|
||||
n = self.NAME.name
|
||||
if self.VARIANT:
|
||||
n = n + '.' + self.VARIANT.name
|
||||
if self.SIMPLE:
|
||||
return n + '(' + repr(self.value) + ')'
|
||||
else:
|
||||
return n + ' ' + repr(self._as_dict())
|
||||
|
||||
def _as_dict(self):
|
||||
raise Exception('Subclass responsibility')
|
||||
|
||||
class Enumeration(SchemaEntity):
|
||||
VARIANTS = None
|
||||
|
||||
def __init__(self):
|
||||
raise Exception('Cannot create instance of Enumeration')
|
||||
|
||||
@classmethod
|
||||
def _set_schema(cls, rootns, module_path, name, schema, _variant, _enumeration):
|
||||
cls.ROOTNS = rootns
|
||||
cls.SCHEMA = schema
|
||||
cls.MODULE_PATH = module_path
|
||||
cls.NAME = name
|
||||
cls.VARIANTS = []
|
||||
for (n, d) in schema[0]:
|
||||
n = Symbol(n)
|
||||
c = pretty_subclass(Definition, module_path_str(module_path + (name,)), n.name)
|
||||
c._set_schema(rootns, module_path, name, d, n, cls)
|
||||
cls.VARIANTS.append((n, c))
|
||||
|
||||
@classmethod
|
||||
def try_decode(cls, v):
|
||||
for (n, c) in cls.VARIANTS:
|
||||
i = c.try_decode(v)
|
||||
if i is not None: return i
|
||||
return None
|
||||
|
||||
def _encode(self):
|
||||
raise Exception('Cannot encode instance of Enumeration')
|
||||
|
||||
class Definition(SchemaEntity):
|
||||
SIMPLE = False
|
||||
FIELD_NAMES = []
|
||||
VARIANT = None
|
||||
ENUMERATION = None
|
||||
|
||||
def __init__(self, *args):
|
||||
self._fields = args
|
||||
if self.SIMPLE:
|
||||
self.value = args[0]
|
||||
else:
|
||||
i = 0
|
||||
for k in self.FIELD_NAMES:
|
||||
setattr(self, k, args[i])
|
||||
i = i + 1
|
||||
|
||||
def _accept(self, visitor):
|
||||
if self.VARIANT is None:
|
||||
return visitor(*self._fields)
|
||||
else:
|
||||
return visitor[self.VARIANT.name](*self._fields)
|
||||
|
||||
@classmethod
|
||||
def _set_schema(cls, rootns, module_path, name, schema, variant, enumeration):
|
||||
cls.ROOTNS = rootns
|
||||
cls.SCHEMA = schema
|
||||
cls.MODULE_PATH = module_path
|
||||
cls.NAME = name
|
||||
cls.SIMPLE = is_simple_pattern(schema)
|
||||
cls.FIELD_NAMES = []
|
||||
cls.VARIANT = variant
|
||||
cls.ENUMERATION = enumeration
|
||||
gather_defined_field_names(schema, cls.FIELD_NAMES)
|
||||
|
||||
@classmethod
|
||||
def try_decode(cls, v):
|
||||
if cls.SIMPLE:
|
||||
i = cls.parse(cls.SCHEMA, v, [])
|
||||
if i is not None: return cls(i)
|
||||
else:
|
||||
args = []
|
||||
if cls.parse(cls.SCHEMA, v, args) is not None: return cls(*args)
|
||||
return None
|
||||
|
||||
def _encode(self):
|
||||
raise Exception('Not yet implemented')
|
||||
|
||||
def _as_dict(self):
|
||||
return dict((k, getattr(self, k)) for k in self.FIELD_NAMES)
|
||||
|
||||
def __getitem__(self, name):
|
||||
return getattr(self, name)
|
||||
|
||||
def __setitem__(self, name, value):
|
||||
return setattr(self, name, value)
|
||||
|
||||
def module_path_str(mp):
|
||||
return '.'.join([e.name for e in mp])
|
||||
|
||||
SIMPLE_PATTERN_KEYS = [ATOM, EMBEDDED, LIT, SEQOF, SETOF, DICTOF, REF]
|
||||
def is_simple_pattern(p):
|
||||
return p == ANY or (isinstance(p, Record) and p.key in SIMPLE_PATTERN_KEYS)
|
||||
|
||||
def gather_defined_field_names(s, acc):
|
||||
if is_simple_pattern(s):
|
||||
pass
|
||||
elif isinstance(s, tuple):
|
||||
for p in s:
|
||||
gather_defined_field_names(p, acc)
|
||||
elif s.key == NAMED:
|
||||
acc.append(s[0].name)
|
||||
gather_defined_field_names(s[1], acc)
|
||||
elif s.key == AND:
|
||||
gather_defined_field_names(s[0], acc)
|
||||
elif s.key == REC:
|
||||
gather_defined_field_names(s[0], acc)
|
||||
gather_defined_field_names(s[1], acc)
|
||||
elif s.key == TUPLE:
|
||||
gather_defined_field_names(s[0], acc)
|
||||
elif s.key == TUPLE_PREFIX:
|
||||
gather_defined_field_names(s[0], acc)
|
||||
gather_defined_field_names(s[1], acc)
|
||||
elif s.key == DICT:
|
||||
gather_defined_field_names(tuple(s[0].values()), acc)
|
||||
else:
|
||||
raise Exception('Bad schema')
|
||||
|
||||
def pretty_subclass(C, module_name, class_name):
|
||||
class S(C): pass
|
||||
S.__module__ = module_name
|
||||
S.__name__ = class_name
|
||||
S.__qualname__ = class_name
|
||||
return S
|
||||
|
||||
def lookup(ns, module_path, name):
|
||||
for e in module_path:
|
||||
if e not in ns:
|
||||
definition_not_found(module_path, name)
|
||||
ns = ns[e]
|
||||
if name not in ns:
|
||||
definition_not_found(module_path, name)
|
||||
return ns[name]
|
||||
|
||||
def definition_not_found(module_path, name):
|
||||
raise Exception('Definition not found: ' + module_path_str(module_path + (name,)))
|
||||
|
||||
class Namespace:
|
||||
def __init__(self, prefix):
|
||||
super(Namespace, self).__setattr__('_items', {})
|
||||
super(Namespace, self).__setattr__('_prefix', prefix)
|
||||
|
||||
def __getattr__(self, name):
|
||||
return self[name]
|
||||
|
||||
def __setattr__(self, name, value):
|
||||
self[name] = value
|
||||
|
||||
def __getitem__(self, name):
|
||||
return self._items[Symbol(name)]
|
||||
|
||||
def __setitem__(self, name, value):
|
||||
name = Symbol(name)
|
||||
if name in self._items:
|
||||
raise Exception('Name conflict: ' + module_path_str(self._prefix + (name.name,)))
|
||||
self._items[name] = value
|
||||
|
||||
def __contains__(self, name):
|
||||
return Symbol(name) in self._items
|
||||
|
||||
def __repr__(self):
|
||||
return repr(self._items)
|
||||
|
||||
class Compiler:
|
||||
def __init__(self):
|
||||
self.root = Namespace(())
|
||||
|
||||
def load(self, filename):
|
||||
filename = pathlib.Path(filename)
|
||||
with open(filename, 'rb') as f:
|
||||
x = Decoder(f.read()).next()
|
||||
if x.key == SCHEMA:
|
||||
self.load_schema((Symbol(filename.stem),), x)
|
||||
elif x.key == BUNDLE:
|
||||
for (p, s) in x[0].items():
|
||||
self.load_schema(p, s)
|
||||
|
||||
def load_schema(self, module_path, schema):
|
||||
if schema[0][VERSION] != 1:
|
||||
raise Exception('Unsupported Schema version')
|
||||
ns = self.root
|
||||
for e in module_path:
|
||||
if not e in ns:
|
||||
ns[e] = Namespace(ns._prefix + (e,))
|
||||
ns = ns[e]
|
||||
for (n, d) in schema[0][DEFINITIONS].items():
|
||||
if isinstance(d, Record) and d.key == OR:
|
||||
superclass = Enumeration
|
||||
else:
|
||||
superclass = Definition
|
||||
c = pretty_subclass(superclass, module_path_str(module_path), n.name)
|
||||
c._set_schema(self.root, module_path, n, d, None, None)
|
||||
ns[n] = c
|
||||
|
||||
if __name__ == '__main__':
|
||||
c = Compiler()
|
||||
schema_bin_filename = pathlib.Path(__file__).parent / '../../../schema/schema.bin'
|
||||
c.load(schema_bin_filename)
|
||||
with open(schema_bin_filename, 'rb') as f:
|
||||
x = Decoder(f.read()).next()
|
||||
print(c.root.schema.Schema.decode(x))
|
||||
|
||||
print()
|
||||
|
||||
d = Compiler()
|
||||
path_bin_filename = pathlib.Path(__file__).parent / '../../../path/path.bin'
|
||||
d.load(path_bin_filename)
|
||||
with open(path_bin_filename, 'rb') as f:
|
||||
x = Decoder(f.read()).next()
|
||||
print(c.root.schema.Schema.decode(x))
|
||||
print()
|
||||
print(d.root)
|
||||
Loading…
Reference in New Issue