In P4, parsers are considered types. Those parsers are instantiated.
The instantiated parsers are values. Previously, gp4 treated a parser
type and a parser value as identical. This PR makes that difference
clear _and_ sets the stage for the future.
TODO: Make the same distinction between control and action types and
values.
Signed-off-by: Will Hawkins <hawkinsw@obs.cr>
Parameterize Runtime (nee ParserRuntime) so that it can run anything
that is LibraryCallable. TODO: Refactor its API -- left mostly as
it was because changing unit tests will be laborious.
Allow the user to customize the evaluation/execution of expressions/
statements with something that implements functions that perform
those tasks. This additional functionality will make it possible for
the "classic" evaluator not to waste time checking for the presence
of interlopers and give implementers additional customization opportunities.
Signed-off-by: Will Hawkins <hawkinsw@obs.cr>
Centralize the execution of statements and evaluation of expressions
so that the user can specify a debugging "callback" after every
execution/evaluation.
The callback can be used for myriad things, but it seems likely that
it will be useful for implementing:
1. Testing
2. Debugger
Signed-off-by: Will Hawkins <hawkinsw@obs.cr>
Will Hawkins