mentat/tx-parser/tests/parser.rs
Nick Alexander 5369f03464 Improve parsing of nested edn::ValueAndSpan streams. r=rnewman (#393)
* Pre: Expose more in edn.

* Pre: Make it easier to work with ValueAndSpan.

with_spans() is a temporary hack, needed only because I don't care to
parse the bootstrap assertions from text right now.

* Part 1a: Add `value_and_span` for parsing nested `edn::ValueAndSpan` instances.

I wasn't able to abstract over `edn::Value` and `edn::ValueAndSpan`;
there are multiple obstacles.  I chose to roll with
`edn::ValueAndSpan` since it exposes the additional span information
that we will want to form good error messages in the future.

* Part 1b: Add keyword_map() parsing an `edn::Value::Vector` into an `edn::Value::map`.

* Part 1c: Add `Log`/`.log(...)` for logging parser progress.

This is a terrible hack, but it sure helps to debug complicated nested
parsers.  I don't even know what a principled approach would look
like; since our parser combinators are so frequently expressed in
code, it's hard to imagine a data-driven interpreter that can help
debug things.

* Part 2: Use `value_and_span` apparatus in tx-parser/.

I break an abstraction boundary by returning a value column
`edn::ValueAndSpan` rather than just an `edn::Value`.  That is, the
transaction processor shouldn't care where the `edn::Value` it is
processing arose -- even we care to track that information we should
bake it into the `Entity` type.  We do this because we need to
dynamically parse the value column to support nested maps, and parsing
requires a full `edn::ValueAndSpan`.  Alternately, we could cheat and
fake the spans when parsing nested maps, but that's potentially
expensive.

* Part 3: Use `value_and_span` apparatus in query-parser/.

* Part 4: Use `value_and_span` apparatus in root crate.

* Review comment: Make Span and SpanPosition Copy.

* Review comment: nits.

* Review comment: Make `or` be `or_exactly`.

I baked the eof checking directly into the parser, rather than using
the skip and eof parsers.  I also took the time to restore some tests
that were mistakenly commented out.

* Review comment: Extract and use def_matches_* macros.

* Review comment: .map() as late as possible.
2017-04-06 10:06:28 -07:00

61 lines
2.4 KiB
Rust

// Copyright 2016 Mozilla
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
// this file except in compliance with the License. You may obtain a copy of the
// License at http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.
extern crate edn;
extern crate combine;
extern crate mentat_tx;
extern crate mentat_tx_parser;
use edn::parse;
use edn::symbols::NamespacedKeyword;
use mentat_tx::entities::{
AtomOrLookupRefOrVectorOrMapNotation,
Entid,
EntidOrLookupRefOrTempId,
Entity,
OpType,
TempId,
};
use mentat_tx_parser::Tx;
#[test]
fn test_entities() {
let input = r#"
[[:db/add 101 :test/a "v"]
[:db/add "tempid" :test/a "v"]
[:db/retract 102 :test/b "w"]]"#;
let edn = parse::value(input).expect("to parse test input");
let result = Tx::parse(edn);
assert_eq!(result.unwrap(),
vec![
Entity::AddOrRetract {
op: OpType::Add,
e: EntidOrLookupRefOrTempId::Entid(Entid::Entid(101)),
a: Entid::Ident(NamespacedKeyword::new("test", "a")),
v: AtomOrLookupRefOrVectorOrMapNotation::Atom(edn::ValueAndSpan::new(edn::SpannedValue::Text("v".into()), edn::Span(23, 26))),
},
Entity::AddOrRetract {
op: OpType::Add,
e: EntidOrLookupRefOrTempId::TempId(TempId::External("tempid".into())),
a: Entid::Ident(NamespacedKeyword::new("test", "a")),
v: AtomOrLookupRefOrVectorOrMapNotation::Atom(edn::ValueAndSpan::new(edn::SpannedValue::Text("v".into()), edn::Span(55, 58))),
},
Entity::AddOrRetract {
op: OpType::Retract,
e: EntidOrLookupRefOrTempId::Entid(Entid::Entid(102)),
a: Entid::Ident(NamespacedKeyword::new("test", "b")),
v: AtomOrLookupRefOrVectorOrMapNotation::Atom(edn::ValueAndSpan::new(edn::SpannedValue::Text("w".into()), edn::Span(86, 89))),
},
]);
}
// TODO: test error handling in select cases.