""" Basic types for GrammarTypes and usefull functions """
import copy
from typing import Union, Any, Callable, Optional, Type, Dict, List
import functools
from collections.abc import Hashable
import numpy as np
import pyparsing as pp
import inspect
from .. import grammar_types
from ..decorators import cached_class_property, cache, \
add_called_class_as_argument, cached_property
from ..alternative_types import normalize_type, allowed_types
from ..grammar import generate_grammar
from ..formats import full_format_for_string
[docs]
class GrammarType:
""" Base class for definition of configuration option types
A type without value (e.g. Separator) are just syntactical
elements in the potentials file, that do not carry an information.
Such elements do not yields (name, value) pair during parsing the file.
Do not confuse this with GrammarType.missing_value functionality.
Missing_value is just the opposite: missing_value can be ommited in the file
(or even the absence of the name in the file carry the information, that
the Flag is False), but the name-value tuple of such Type is present
in the parse result. On the other hand, has_value = False is in the file, but
not in the result.
**The functions called during...**
::
User input: convert, validate
Output: string -> _string
Parsing: parse -> ( <_grammar parse actions>, validate(why='parse') )
"""
has_value = True
name_in_grammar = True
""" Default value for ValueDefinition.name_in_grammar.
Some types (e.g. Tables) commonly have no name (are identified
by its position in the potential file) -- such type could redefine
this class property."""
default_value = None
""" Default value for the given type. It can be overriden for particular instances
in the constructor (or just by setting the attribute of an instantiated object). """
numpy_type = object
""" The numpy dtype of the array, that contains values of this type (see e.g. :class:`Array`).
The default type ``object`` can and should be redefined in the descendatns. """
array_access = False
""" The value of this type can be accessed as array """
is_independent_on_the_predecessor = False
""" Options of most grammar types do not identify themselves, so they have to be either identified by their names, or if name is not given, by their predecessors. Hoewever, e.g. keyword arguments can be identified just by their value."""
[docs]
def __init__(self, prefix:Union[str,None]=None, postfix:Union[str,None]=None,
format:str='', after_format:Optional[str]=None,
default_value:Any=None,
condition:Union[Callable[[Any], Union[bool,str]],None]=None,
after_convert:Union[Callable[[Any], Any],None]=None,
description=''):
"""
Create the object.
Parameters
----------
prefix
The string, that will be printed before the value
postfix
The string, that will be printed after the value
format
The (python) format string, that will be used for outputing the value.
The format is passed as format argument to ``str.format`` routine.
after_format
In some cases, the additional formating is required after converting to the string
and adding postfix/prefix.
default_value
The default value of the options of this type. ``None`` means no default value.
condition
Function, that check the validity of the value. It should return ``True`` for a valid
value, and ``False`` or string for invalid. The string is interpreted as an error message
that explains the invalidity of the value.
after_convert
Function, that - if it is given - is applied to the (entered or parsed) value. The function
is applied on the result of the
:meth:`convert<ase2sprkkr.common.grammar_types.GrammarType.convert>` method
"""
self.prefix = prefix
""" The string, that will be printed before the value """
self.postfix = postfix
""" The string, that will be printed after the value """
self._format = format
self.after_format = after_format if not after_format or '{' in after_format else \
f'{{:{after_format}}}'
""" The (python) format string, that will be used for printing the value.
The format is passed as format argument to ``str.format`` routine. """
self.condition = condition
if after_convert is not None:
self.convert = lambda v: \
after_convert(self, self.__class__.convert(self, v))
""" Some subclasses has default_value defined via read-only property. """
if default_value is not None:
self.default_value = self.convert(default_value)
self._description = description
def __str__(self):
return self.__class__.__name__
@cached_property
def format(self):
""" Return the resulting format string, applying the prefix and postfix """
if not self._format and not self.prefix and not self.postfix:
return None
out = self._format or ''
if '{' not in out:
out=f'{{:{out}}}'
escape = lambda x: x.replace('{','{{').replace('}', '}}')
if self.prefix:
out=escape(self.prefix) + out
if self.postfix:
out+=escape(self.postfix)
return out
@format.setter
def format(self, v):
self._format = v
if 'format' in self.__dict__:
del self.__dict__['format']
[docs]
@staticmethod
def is_the_same_value(a,b):
""" Comparison function for the values of "this type".
Not all values (e.g. numpy arrays) can be compared by equal sign,
so this function has to be used for comparison of the values.
"""
return a == b
[docs]
@cache
def grammar(self, param_name:str=False):
""" Return a pyparsing grammar for the type
Parameters
----------
param_name
The name of the value, that can be assigned to the generated grammar element.
"""
grammar = self._grammar
if isinstance(self._grammar, pp.ParserElement):
grammar = pp.Forward()
grammar << self._grammar
else:
grammar = grammar(param_name)
if self.prefix or self.postfix:
with generate_grammar():
if self.prefix:
grammar = pp.Literal(self.prefix).suppress().setName(self.prefix) + grammar
if self.postfix:
grammar += pp.Literal(self.postfix).suppress().setName(self.postfix)
grammar = self.transform_grammar(grammar, param_name)
if self.has_value:
def validate(s, loc, x):
try:
self.validate(x[0], why='parse', param_name=param_name)
except ValueError as e:
raise pp.ParseException(s, loc, str(e) + '\nValidating of the parsed value failed') from e
return x
grammar.addParseAction(validate)
grammar.grammar_type = self
return grammar
[docs]
def parse(self, str, whole_string=True):
"""
Parse the string, return the obtained value.
"""
return self.grammar().parseString(str, whole_string)[0]
[docs]
async def parse_from_stream(self, stream, up_to, start=None, whole_string=True):
result = await stream.readuntil(up_to)
result = result[:-len(up_to)].decode('utf8')
if start:
result = start + result
return self.parse(result, whole_string)
[docs]
def grammar_name(self):
""" Human readable expression of the grammar. By default,
this is what is set by grammar.setName, however, sometimes
is desirable to set even shorter string """
if not isinstance(self.grammar, pp.ParserElement):
return self.__class__.__name__
return str(self.grammar)
[docs]
def missing_value(self):
""" Is the configuraion value a flag? I.e., can be =<value> ommited
in the configuration?
Return
------
can_be_ommited : bool
Is an ommision of the value possible, e.g. the option is given as Flag (only by name of the option)
default_value
The value used if the value is ommitted
do_not_output_the_option
The value, for which the variable should not be outputed at all (e.g. False for a flag)
"""
return False, None, None
[docs]
def validate(self, value, param_name='<Unknown>', why:str='set'):
""" Validate either the pyparsing result or a user given value.
Do not override this method in subclasses for the validation implementation,
this method calls :meth:`_validate`, which should contain the actual validation
Parameters
---------
value : mixed
Value to be validated.
param_name : str or callable
Parameter name to be used in possible throwed exception (Optional).
If it is callable, it should be a function that returns the param_name.
why
Possible values are:
``set``
validation value setted by user (in rare cases, such value can be incomplete
and requires `completing` during ``set_from_atoms`` call before saving the output)
``parse``
validation during parsing input file, checks enforced
by the grammar can be skipped
``save``
validation before saving the values
"""
try:
err = self._validate(value, why)
except ValueError as err:
self._valueError(value, err, param_name)
if err is not True:
self._valueError(value, err, param_name)
if self.condition:
err = self.condition(value)
if err is not True:
self._valueError(value, err, param_name)
return True
[docs]
def _validate(self, value, why='set'):
""" Return error message if the value is not valid. """
return True
[docs]
def _valueError(self, value, error_message=False, param_name=False):
if callable(param_name):
param_name = param_name()
if param_name:
param = f'for paramater {param_name} of type {self}'
else:
param = f'for type {self}'
if error_message is False:
error_message = 'invalid value'
if isinstance(error_message, Exception):
raise ValueError("Value '{}' {} is not valid: {}".format(value, param, error_message)) from error_message
else:
raise ValueError("Value '{}' {} is not valid: {}".format(value, param, error_message))
[docs]
def convert(self, value):
""" Convert a value from user to the "cannonical form" """
return value
[docs]
def _string(self, val):
"""
Convert the value to the ouput.
The :meth:`string` apply format and do some additional transformation (add prefix, postfix etc.),
so the actual way how to convert the value for the output should be here. """
return val
[docs]
def string(self, val):
""" Convert the value to the string according to the class definition.
Before redefining this method, you should consider, whether :meth:`_string` method could be
redefined instead. Otherwise, you should call :meth:`apply_format` in the redefined method.
to retain the common functionality (as adding prefix or postfix to the resulting
string).
"""
val = self._string(val)
val = self.apply_format(val)
return val
[docs]
def write(self, f, val):
""" Output the value to the stream (in the propper format). """
f.write(self.string(val))
[docs]
def print(self, val):
""" Output the value to stdout (in the propper format). """
print(self.string(val))
[docs]
def copy(self):
return copy.copy(self)
[docs]
def enrich(self, option):
""" Some types can add properties to the options that have
the type, e.g. see Sequence.enrich, which adds the ability to
access the items of the sequence using [] """
pass
def __repr__(self):
return "<{}>".format(self.__class__.__name__)
[docs]
def additional_description(self, prefix='') -> str:
""" If the description of the type does not fit on one line,
this method should return
Returns
-------
additional_description
The additional description (e.g. possible choices) of the type. Multiline string.
"""
out = self._description
if prefix and out:
out = out.replace('\n', '\n' + prefix)
return out
[docs]
def type_validation(self, value, types:Union[List[Type], Type], typename:Optional[str]=None):
"""
Parameters
----------
value: mixed
Value to be checked
types
The required type or types. If more types is given, it is sufficient, if the value is of
any of given types.
Returns
-------
error_message: Union[str, bool]
The function returns either False, if the value is ok, or string containing an error
message describing the error.
"""
if isinstance(value, types):
return True
if not typename:
typename = types
typename=str(typename)
n = 'n' if typename[0] in ['a','e','i','o','u'] else ''
return f"A{n} <{typename}> value is required, a value {value} of type {value.__class__} have been given"
[docs]
def copy_value(self, value):
return value
[docs]
def used_in_definition(self, definition):
pass
[docs]
def added_to_container(self, definition):
pass
@add_called_class_as_argument
def add_to_parent_validation(validation):
@functools.wraps(validation)
def wrapped(cls, self, value, why='set'):
out = super(cls, self)._validate(value, why)
if out is not True:
return out
return validation(self, value, why)
return wrapped
[docs]
class TypedGrammarType(GrammarType):
@cached_class_property
def datatype(cls):
""" The (primary) type of the value. Redefine it in the descendants, if it is needed. """
return cls.numpy_type
@cached_class_property
def allowed_types(cls):
""" Allowed alternative types, that will be converted to the 'primary' datatype. """
dt = cls.datatype
return allowed_types.get(dt, (dt, ))
[docs]
def convert(self, value):
if isinstance(value, self.datatype):
return value
for i in self.allowed_types:
if isinstance(value, i):
return self.datatype(value)
return value
@cached_class_property
def datatype_name(cls):
return cls.__name__.lower()
[docs]
def _validate(self, value, why='set'):
return self.type_validation(value, self.allowed_types, self.datatype_name)
[docs]
def type_from_type(type, format:Union[str,Dict]='', format_all:bool=False, type_map:Dict={}):
""" Guess and return the grammar element (GrammarType class descendatnt) from a python type. E.g. int => Integer.
The given format can be optionally set to the returned grammar element.
Parameters
----------
type: A python type or GrammarType
A type to be converted to a grammar type (GrammarType class descendant)
format
The format to be applied to the resulting class. If dict is given, see :func:`format_for_type`
for the way how the format is determined
format_all
If False (default), the format is not applied, if instance of GrammarType is given as
the type parameter. Otherwise, a copy of the input type with the applied format is returned
type_map
"""
if isinstance(type, dict):
return grammar_types.Keyword(type)
type_from_type_map = grammar_types.type_from_type_map
if isinstance(type, GrammarType):
if format_all:
type = type.copy()
type.format = format_for_type(format, normalize_type(type.numpy_type))
return type
if isinstance(type, Hashable):
type = normalize_type(type)
if type in type_map:
type = type_map[type]
elif type in type_from_type_map:
type = type_from_type_map[type]
else:
return type
format = format_for_type(format, type)
if format:
type = type.copy()
type.format = format
return type
[docs]
def type_from_value(value, type_map={}):
""" Gues the grammar type from a python value.
..doctest::
>>> type_from_value(2)
<Integer>
>>> type_from_value(2.0)
<Real>
"""
type_from_set_map = grammar_types.type_from_set_map
if isinstance(value, recognized_set_types):
return type_from_set_map[normalize_type(value[0].__class__)] if len(value) else grammar_types.Integer.I
if isinstance(value, str):
try:
grammar_types.String._grammar.parseString(value, True)
return grammar_types.String.I
except Exception:
return grammar_types.QString.I
if isinstance(value, dict):
return grammar_types.Keyword(value)
type = type_from_type(value.__class__, type_map=type_map)
if type is value.__class__:
raise ValueError(f'Cannot determine grammar type from value {value}')
return type.__class__(default_value = value)
[docs]
def type_from_default_value(value, format='', format_all=False, type_map={}):
""" Guess the grammar type from a value, that will become the default value of the grammar type.
It has to create a new object instance, as it has to set the default
value property of the returned object. An (output) format can be applied to the
resulting grammar type
Grammar types passed as types are left as is, unless format_all flag is set.
"""
if inspect.isclass(value) or isinstance(value, GrammarType):
return type_from_type(value, format=format, format_all=format_all, type_map={})
ptype = normalize_type(value.__class__)
gtype = type_from_type(value.__class__, type_map=type_map).__class__
return gtype(default_value = value, format=format_for_type(format, ptype))
[docs]
def compare_numpy_values(a,b):
""" The numpy arrays cannot be compared by =, that's why this method.
However, the method is still far from to be perfect, it can not
compare nested numpy arrays.
"""
return np.array_equal(a,b)
recognized_set_types = ( list, tuple, np.ndarray )
""" The types, that are recognized as 'list of values' and so that will
be accepted as values for array_like type (e.g. :class:`Array` or :class:`SetOf`). """