reven2.types._type.Type

class documentation

class Type(object):

Known subclasses: reven2.types._array.Array, reven2.types._declaration.UnresolvedDeclaration, reven2.types._enum.Enumeration, reven2.types._error.ErrorType, reven2.types._integer.Integer, reven2.types._pointer.Pointer, reven2.types._primitive.Primitive, reven2.types._primitive.PrimitiveBool, reven2.types._string.CString, reven2.types._struct.Struct, reven2.types._void.VoidType

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An abstract class whose instances represent a type. Refer to the module documentation for details.

Implementers must provide the _construct_type method.

Method	`description`	The short description of this type.
Method	`is_context_sensitive`	Whether the context argument needed by some methods actually has an effect.
Method	`parse`	Parses the value of an instance of this type from a raw buffer, possibly depending on the context.
Method	`size_bytes`	The minimal number of bytes necessary to hold an instance of this type, possibly depending on the context.
Method	`to_bytes`	Build a byte buffer from a value of this type.
Method	`_construct_type`	Return the underlying `construct` instance
Method	`_resolve`	Uses the resolver to return a resolved version of the type, if possible.

def description(self):

overridden in reven2.types._declaration.UnresolvedDeclaration, reven2.types._enum.Enumeration, reven2.types._error.ErrorType, reven2.types._struct.Struct

The short description of this type.

For named types, it is the name of the type. For other types, it is generally __str__.

Returns
`str`	Undocumented

def is_context_sensitive(self):

overridden in reven2.types._array.Array, reven2.types._enum.Enumeration, reven2.types._integer.ArchDependentInteger, reven2.types._integer.BigEndian, reven2.types._integer.LittleEndian, reven2.types._pointer.Pointer, reven2.types._struct.Struct

Whether the context argument needed by some methods actually has an effect.

Types that return False to this method are context-insensitive types. You can safely pass any object as context parameter (including None) to the methods of such type.

Note that the context-sensitivity of a type may change in the future.

Examples

Getting the size of a type without needing a context for context-insensitive types: >>> types.U32.is_context_sensitive() False >>> types.U32.size_bytes(context=None) 4 >>> array32_12 = types.Array(types.U32, 12) >>> array32_12.is_context_sensitive() False >>> array32_12.size_bytes() # context=None by default 48

Context-sensitive types may raise errors when attempting to get the size without a context: >>> types.USize.is_context_sensitive() True >>> types.USize.size_bytes(context=None) ValueError: Please provide a context when using a context-sensitive type

Returns
`bool`	Undocumented

def parse(self, buf, context=None):

overridden in reven2.types._declaration.UnresolvedDeclaration

Parses the value of an instance of this type from a raw buffer, possibly depending on the context.

Information

Parameters
buf:`bytes`	Undocumented
context	The context object. See package documentation.
Returns
`_Any`	Undocumented

def size_bytes(self, context=None):

overridden in reven2.types._declaration.UnresolvedDeclaration, reven2.types._integer.Integer, reven2.types._pointer.Pointer, reven2.types._string.CString

The minimal number of bytes necessary to hold an instance of this type, possibly depending on the context.

Returns
`int`	Undocumented

def to_bytes(self, value, context=None):

overridden in reven2.types._declaration.UnresolvedDeclaration

Build a byte buffer from a value of this type.

Examples

Converting some values to their byte representation.

>>> F32.to_bytes(0.222)
b'øSc>'
>>> Array(U16, 2).to_bytes([0xfe, 0xfeff])
b'þÿþ'
>>> BigEndian(U16).to_bytes(0xfffe)
b'ÿþ'
>>> U16.to_bytes(0xfffe)
b'þÿ'

Information

Parameters
value:`_Any`	Undocumented
context:`_Any`	The context object. See package documentation.
Returns
`bytes`	Undocumented

def _construct_type(self, context=None):

overridden in reven2.types._array.Array, reven2.types._declaration.UnresolvedDeclaration, reven2.types._enum.Enumeration, reven2.types._error.ErrorType, reven2.types._integer.Integer, reven2.types._pointer.Pointer, reven2.types._primitive.Primitive, reven2.types._primitive.PrimitiveBool, reven2.types._string.CString, reven2.types._struct.Struct, reven2.types._void.VoidType

Return the underlying construct instance

Returns
`_construct.core.Construct`	Undocumented

def _resolve(self, resolver):

overridden in reven2.types._array.Array, reven2.types._declaration.UnresolvedDeclaration, reven2.types._pointer.Pointer

Uses the resolver to return a resolved version of the type, if possible.

Parameters
resolver:`TypeResolver`	Undocumented
Returns
`Type`	Undocumented