Common functionality for all attributes.
An attribute of a node type T
with value of type U
which has a circular
definition.
A constant attribute of a node type T
with value of type U
.
Support for parameterised attributes: argument, node pair comparison.
Define a named circular attribute of T
nodes of type U
by the function
f
.
Define a named circular attribute of T
nodes of type U
by the function
f
. f
is allowed to depend on the value of this attribute, which will
be given by init
initially and will be evaluated iteratively until a
fixed point is reached (in conjunction with other circular attributes
on which it depends). The final value is cached. name
is used in
debugging output to identify this attribute.
Define an anonymous circular attribute of T
nodes of type U
by the
function f
.
Define an anonymous circular attribute of T
nodes of type U
by the
function f
. f
is allowed to depend on the value of this attribute,
which will be given by init
initially and will be evaluated iteratively
until a fixed point is reached (in conjunction with other circular
attributes on which it depends). The final value is cached.
Define an optionally named circular attribute of T
nodes of type U
by the function f
.
Define an optionally named circular attribute of T
nodes of type U
by the function f
. f
is allowed to depend on the value of this
attribute, which will be given by init
initially and will be evaluated
iteratively until a fixed point is reached (in conjunction with other
circular attributes on which it depends). The final value is cached.
If optNameDef
is not None
, then optNameDef.get
is used in
debugging output to identify this attribute.
Define an optionally named constanat attribute of T
nodes of type U
given by the value u
.
Define an optionally named constanat attribute of T
nodes of type U
given by the value u
. u
is evaluated at most once. name
is used
in debugging output to identify this attribute.
Define an anonymous constanat attribute of T
nodes of type U
given by the value u
.
Define an anonymous constanat attribute of T
nodes of type U
given by the value u
. u
is evaluated at most once.
Define an optionally named constanat attribute of T
nodes of type U
given by the value u
.
Define an optionally named constanat attribute of T
nodes of type U
given by the value u
. u
is evaluated at most once. If optNameDef
is not None
, then optNameDef.get
is used in debugging output to
identify this attribute.
Initialise the Attributable
tree rooted at t
so that it is ready for
attribution.
Initialise the Attributable
tree rooted at t
so that it is ready for
attribution. At present, the only initialisation performed is to set node
attributes such as parent and children so that nodes can generically refer
to their neighbours. If you wish to use any of these properties, you must
call this method before doing so. Otherwise, the node properties should
not be used and there is no need to call this method.
Base support for attribution of syntax trees in a functional style. Includes circular attributes but needs to be augmented with basic attributes and parameterised attributes.