Summary:
The type system is modelled after "CIP2015-09-16"
https://github.com/opencypher/openCypher/blob/master/cip/1.accepted/CIP2015-09-16-public-type-system-type-annotation.adoc
This is needed for registering procedures and their signatures. The
users will be able to specify what a custom procedure accepts and
returns. All of this needs to be available for inspection during
runtime. Therefore, this diff implements printing types as a user
presentable string. In the future, we will probably want to add type
checking through these types, because openCypher requires type checking
on values passed in and returned from custom procedures.
Reviewers: mferencevic, ipaljak, dsantl
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2544
Summary:
This makes the concrete memory resource an explicit argument in custom
procedures. Unfortunately, the API is a bit uglier but at least we don't
have to worry about threading, global state or similar. This is the
primary reason for this change as we would probably like to allow
procedures to spawn threads to compute stuff in a parallel fashion.
Reviewers: mferencevic, dsantl
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2495
Summary:
The `mg_value` is the main data type used in upcoming custom procedures. Each
custom procedure will receive arguments as an array of `mg_value` instances.
The results of custom procedures will also be built as `mg_value` instances.
We should strive to have as simple and straightforward C API for custom
procedures, because we want to limit the possibility of errors and bugs on the
user facing side. Custom procedures will run in Memgraph and as such can cause
crashes and potentially a lot of nasty stuff. The burden is on the writer of
custom procedures not to mess things up, so we should make messing things up
from the C API hard if not impossible to do.
Reviewers: mferencevic, ipaljak, dsantl
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2443
