* Pre: Order datoms deterministically in debug output.
This makes comparison much easier, and avoids a whole class of
difficult problems when introducing pattern matching with placeholder
values.
* Pre: Don't rewrite ?txN and ?msN in debug module into_edn() methods.
* Convert EDN transaction tests to Rust code. Fixes#271.
This implements
https://github.com/mozilla/mentat/issues/271#issuecomment-283125963.
I'm using the EDN pattern matching functionality
internally (extensively!), but specifically working around the tricky
edges we encountered. This should let us implement tests quickly (and
hopefully legibly) while not requiring us to encode as much behaviour
into non-standard EDN notations.
For queries like
```edn
[:find ?x :where [?x _ "hello"]]
[:find [?v ...] :where [_ ?a ?v]]
```
we'll query `all_datoms` to handle fulltext strings, which is expensive.
If `?a` is bound, we can avoid this — resolve any keyword binding,
ensure that the value is an attribute, and use the appropriate table.
* Part 1: added limits feature to rusqlite dependencies.
* Part 2: replace references to SQLITE_MAX_VARIABLE_NUMBER with sqlite3_limit.
* Move assertion check for correct number of variables in repeat_values to before call as this is where the variable is defined.
* Part 3: add tests
This is necessary because we process patterns sequentially; a later
pattern might tell us the type of a variable (e.g., by having a
constant attribute), at which point we can do less work.
* Add a failing test for EDN parsing '…'.
* Expose a SQLValueType trait to get value_type_tag values out of a ValueType.
* Add accessors to FindSpec.
* Implement querying.
* Implement rudimentary projection.
* Export mentat_db::new_connection.
* Export symbols from mentat.
* Add rudimentary end-to-end query tests.
* Add top-level `Conn`. Fixes#296.
This is a little different than the API rnewman and I originally
discussed in https://public.etherpad-mozilla.org/p/db-conn-thoughts.
A few notes:
- I was led to make a `Schema` instance the thing that is shared,
rather than a `db::DB`. It's possible that queries will want to
know the current transaction at some point (to prevent races, or to
query historical data), but that can be a future consideration.
- The generation number just allows for a cheap comparison. I don't
care to handle races to transact just yet; the long term plan might
be to make embedding applications responsible for avoiding races, or
we might handle queuing transactions and yielding report futures in
Mentat itself.
- The sharing of the partition maps is a little more subtle than
expected. Partition maps are volatile: a successful Mentat
transaction always advances the :db.part/tx partition, so it's not
worth passing references around. This means that consumers must
clone in order to maintain just a single clone per transaction.
Clean some cruft.
* Review comments.
* Pre: Drop unneeded tx0 from search results.
* Pre: Don't require a schema in some of the DB code.
The idea is to separate the transaction applying code, which is
schema-aware, from the concrete storage code, which is just concerned
with getting bits onto disk.
* Pre: Only reference Schema, not DB, in debug module.
This is part of a larger separation of the volatile PartitionMap,
which is modified every transaction, from the stable Schema, which is
infrequently modified.
* Pre: Fix indentation.
* Extract part of DB to new SchemaTypeChecking trait.
* Extract part of DB to new PartitionMapping trait.
* Pre: Don't expect :db.part/tx partition to advance when tx fails.
This fails right now, because we allocate tx IDs even when we shouldn't.
* Sketch a db interface without DB.
* Add ValueParseError; use error-chain in tx-parser.
This can be simplified when
https://github.com/Marwes/combine/issues/86 makes it to a published
release, but this unblocks us for now. This converts the `combine`
error type `ParseError<&'a [edn::Value]>` to a type with owned
`Vec<edn::Value>` collections, re-using `edn::Value::Vector` for
making them `Display`.
* Pre: Accept Borrow<Schema> instead of just &Schema in debug module.
This makes it easy to use Rc<Schema> or Arc<Schema> without inserting
&* sigils throughout the code.
* Use error-chain in query-parser.
There are a few things to point out here:
- the fine grained error types have been flattened into one crate-wide
error type; it's pretty easy to regain the granularity as needed.
- edn::ParseError is automatically lifted to
mentat_query_parser::errors::Error;
- we use mentat_parser_utils::ValueParser to maintain parsing error
information from `combine`.
* Patch up top-level.
* Review comment: Only `borrow()` once.
These expand into a collection of named variables that should be
passed via bind parameters when the query is executed.
Bind parameters are now only named.
* Implement pretty printing
Signed-off-by: Victor Porof <victor.porof@gmail.com>
* Rewrite pretty printing.
This does a few things. First, it use pretty.rs directly, without the
layer of macro obfuscation. The code is significantly simpler as a
result.
Second, it tightens the layout, using pretty.rs to group nested
layouts that fit on a single line. This is Clojure's EDN style, more
or less.
Third, it drops "special format" support for queries. This wasn't
completely implemented; if we want it, we can newtype
Query(edn::Value) and figure out how to really implement this idea.
* Rename to reflect functionality.
* Make write interface more Rust-like.
There isn't a clear standard in the stdlib, but a function that takes
ownership of a writer and then returns it back is definitely not
Rust-like. That's what a (mutable) reference is for.
* Review comment: Use as_ref to avoid cloning strings.
* Post: Fix tests to use `without_spans()`.
Printing out failure to meet rustc version helps users during
setup with a helpful message if using an older rustc.
Rust version checking from http://stackoverflow.com/a/36607492.
