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Parse basic :find and :where clauses. (#211) r=nalexander

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* Make Variable::from_symbol public.
* Implement basic parsing of queries.
* Use pinned dependencies the hard way to fix Travis.
* Bump ordered-float dependency to 0.4.0.
* Error coercions to use ?, and finishing the find interface.
This commit is contained in:
Richard Newman 2017-02-02 18:32:00 -08:00 committed by GitHub
parent cd5f0d642c
commit 5b770a54cd
11 changed files with 569 additions and 243 deletions
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2
db/Cargo.toml
View file

@ -7,7 +7,7 @@ error-chain = "0.8.0"
lazy_static = "0.2.2"
# TODO: don't depend on num and ordered-float; expose helpers in edn abstracting necessary constructors.
num = "0.1.35"
ordered-float = "0.3.0"
ordered-float = "0.4.0"
[dependencies.rusqlite]
version = "0.9.3"

2
edn/Cargo.toml
View file

@ -11,7 +11,7 @@ readme = "./README.md"
[dependencies]
num = "0.1.35"
ordered-float = "0.3.0"
ordered-float = "0.4.0"
[build-dependencies]
peg = "0.4"

2
query-parser/Cargo.toml
View file

@ -4,6 +4,8 @@ version = "0.0.1"
[dependencies]
combine = "2.1.1"
matches = "0.1"
ordered-float = "0.4.0"
[dependencies.edn]
path = "../edn"

41
query-parser/src/error.rs
View file

@ -1,41 +0,0 @@
// 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 combine;
extern crate edn;
extern crate mentat_query;
use self::mentat_query::{FindSpec, FindQuery};
#[derive(Clone,Debug,Eq,PartialEq)]
pub struct NotAVariableError(pub edn::Value);
#[derive(Clone,Debug,Eq,PartialEq)]
pub enum FindParseError {
Err,
}
#[derive(Clone,Debug,Eq,PartialEq)]
pub enum QueryParseError {
InvalidInput(edn::Value),
EdnParseError(edn::parse::ParseError),
MissingField(edn::Keyword),
FindParseError(FindParseError),
}
impl From<edn::parse::ParseError> for QueryParseError {
fn from(err: edn::parse::ParseError) -> QueryParseError {
QueryParseError::EdnParseError(err)
}
}
pub type FindParseResult = Result<FindSpec, FindParseError>;
pub type QueryParseResult = Result<FindQuery, QueryParseError>;

107
query-parser/src/find.rs
View file

@ -38,10 +38,36 @@ extern crate mentat_query;
use std::collections::BTreeMap;
use self::mentat_query::{FindQuery, SrcVar};
use self::mentat_query::{
FindQuery,
FromValue,
SrcVar,
Variable,
};
use super::error::{QueryParseError, QueryParseResult};
use super::util::{values_to_variables, vec_to_keyword_map};
use super::parse::{
NotAVariableError,
QueryParseError,
QueryParseResult,
clause_seq_to_patterns,
};
use super::util::vec_to_keyword_map;
/// If the provided slice of EDN values are all variables as
/// defined by `value_to_variable`, return a `Vec` of `Variable`s.
/// Otherwise, return the unrecognized Value in a `NotAVariableError`.
fn values_to_variables(vals: &[edn::Value]) -> Result<Vec<Variable>, NotAVariableError> {
let mut out: Vec<Variable> = Vec::with_capacity(vals.len());
for v in vals {
if let Some(var) = Variable::from_value(v) {
out.push(var);
continue;
}
return Err(NotAVariableError(v.clone()));
}
return Ok(out);
}
#[allow(unused_variables)]
fn parse_find_parts(find: &[edn::Value],
@ -63,19 +89,27 @@ fn parse_find_parts(find: &[edn::Value],
let source = SrcVar::DefaultSrc;
// :with is an array of variables. This is simple, so we don't use a parser.
let with_vars = with.map(values_to_variables);
let with_vars = if let Some(vals) = with {
values_to_variables(vals)?
} else {
vec![]
};
// :wheres is a whole datastructure.
let where_clauses = clause_seq_to_patterns(wheres)?;
super::parse::find_seq_to_find_spec(find)
.map(|spec| {
FindQuery {
find_spec: spec,
default_source: source,
with: with_vars,
in_vars: vec!(), // TODO
in_sources: vec!(), // TODO
where_clauses: where_clauses,
}
})
.map_err(QueryParseError::FindParseError)
}
fn parse_find_map(map: BTreeMap<edn::Keyword, Vec<edn::Value>>) -> QueryParseResult {
@ -136,3 +170,64 @@ pub fn parse_find(expr: edn::Value) -> QueryParseResult {
}
return Err(QueryParseError::InvalidInput(expr));
}
#[cfg(test)]
mod test_parse {
extern crate edn;
use self::edn::{NamespacedKeyword, PlainSymbol};
use self::edn::types::{to_keyword, to_symbol};
use super::mentat_query::{
Element,
FindSpec,
Pattern,
PatternNonValuePlace,
PatternValuePlace,
SrcVar,
Variable,
WhereClause,
};
use super::*;
// TODO: when #224 lands, fix to_keyword to be variadic.
#[test]
fn test_parse_find() {
let truncated_input = edn::Value::Vector(vec![to_keyword(None, "find")]);
assert!(parse_find(truncated_input).is_err());
let input = edn::Value::Vector(vec![
to_keyword(None, "find"),
to_symbol(None, "?x"),
to_symbol(None, "?y"),
to_keyword(None, "where"),
edn::Value::Vector(vec![
to_symbol(None, "?x"),
to_keyword("foo", "bar"),
to_symbol(None, "?y"),
]),
]);
let parsed = parse_find(input).unwrap();
if let FindSpec::FindRel(elems) = parsed.find_spec {
assert_eq!(2, elems.len());
assert_eq!(vec![
Element::Variable(Variable(edn::PlainSymbol::new("?x"))),
Element::Variable(Variable(edn::PlainSymbol::new("?y"))),
], elems);
} else {
panic!("Expected FindRel.");
}
assert_eq!(SrcVar::DefaultSrc, parsed.default_source);
assert_eq!(parsed.where_clauses,
vec![
WhereClause::Pattern(Pattern {
source: None,
entity: PatternNonValuePlace::Variable(Variable(PlainSymbol::new("?x"))),
attribute: PatternNonValuePlace::Ident(NamespacedKeyword::new("foo", "bar")),
value: PatternValuePlace::Variable(Variable(PlainSymbol::new("?y"))),
tx: PatternNonValuePlace::Placeholder,
})]);
}
}

6
query-parser/src/lib.rs
View file

@ -8,10 +8,14 @@
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.
#[macro_use]
extern crate matches;
#[macro_use]
extern crate mentat_parser_utils;
mod error;
#[macro_use]
mod parser_util;
mod util;
mod parse;
pub mod find;

369
query-parser/src/parse.rs
View file

@ -10,155 +10,206 @@
extern crate combine;
extern crate edn;
extern crate mentat_parser_utils;
extern crate mentat_query;
use self::combine::{eof, many1, parser, satisfy_map, Parser, ParseResult, Stream};
use self::combine::combinator::{Expected, FnParser, choice, try};
use self::edn::Value::PlainSymbol;
use self::mentat_query::{Element, FromValue, FindSpec, Variable};
use self::mentat_parser_utils::ResultParser;
use self::combine::{eof, many1, optional, parser, satisfy_map, Parser, ParseResult, Stream};
use self::combine::combinator::{choice, try};
use self::mentat_query::{
Element,
FindQuery,
FindSpec,
FromValue,
Pattern,
PatternNonValuePlace,
PatternValuePlace,
SrcVar,
Variable,
WhereClause,
};
use super::error::{FindParseError, FindParseResult};
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct NotAVariableError(pub edn::Value);
pub struct FindSp<I>(::std::marker::PhantomData<fn(I) -> I>);
#[allow(dead_code)]
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum FindParseError {
Err,
}
type FindSpParser<O, I> = Expected<FnParser<I, fn(I) -> ParseResult<O, I>>>;
#[allow(dead_code)]
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum WhereParseError {
Err,
}
fn fn_parser<O, I>(f: fn(I) -> ParseResult<O, I>, err: &'static str) -> FindSpParser<O, I>
#[derive(Clone,Debug,Eq,PartialEq)]
pub enum QueryParseError {
InvalidInput(edn::Value),
EdnParseError(edn::parse::ParseError),
MissingField(edn::Keyword),
FindParseError(FindParseError),
WhereParseError(WhereParseError),
WithParseError(NotAVariableError),
}
impl From<edn::parse::ParseError> for QueryParseError {
fn from(err: edn::parse::ParseError) -> QueryParseError {
QueryParseError::EdnParseError(err)
}
}
impl From<WhereParseError> for QueryParseError {
fn from(err: WhereParseError) -> QueryParseError {
QueryParseError::WhereParseError(err)
}
}
impl From<NotAVariableError> for QueryParseError {
fn from(err: NotAVariableError) -> QueryParseError {
QueryParseError::WithParseError(err)
}
}
pub type WhereParseResult = Result<Vec<WhereClause>, WhereParseError>;
pub type FindParseResult = Result<FindSpec, FindParseError>;
pub type QueryParseResult = Result<FindQuery, QueryParseError>;
pub struct Query<I>(::std::marker::PhantomData<fn(I) -> I>);
impl<I> Query<I>
where I: Stream<Item = edn::Value>
{
parser(f).expected(err)
}
/// `satisfy_unwrap!` makes it a little easier to implement a `satisfy_map`
/// body that matches a particular `Value` enum case, otherwise returning `None`.
macro_rules! satisfy_unwrap {
( $cas: path, $var: ident, $body: block ) => {
satisfy_map(|x: edn::Value| if let $cas($var) = x $body else { None })
fn to_parsed_value<T>(r: ParseResult<T, I>) -> Option<T> {
r.ok().map(|x| x.0)
}
}
impl<I> FindSp<I>
where I: Stream<Item = edn::Value>
{
fn variable() -> FindSpParser<Variable, I> {
fn_parser(FindSp::<I>::variable_, "variable")
}
def_value_satisfy_parser_fn!(Query, variable, Variable, Variable::from_value);
def_value_satisfy_parser_fn!(Query, source_var, SrcVar, SrcVar::from_value);
fn variable_(input: I) -> ParseResult<Variable, I> {
satisfy_map(|x: edn::Value| Variable::from_value(&x)).parse_stream(input)
}
pub struct Where<I>(::std::marker::PhantomData<fn(I) -> I>);
fn period() -> FindSpParser<(), I> {
fn_parser(FindSp::<I>::period_, "period")
}
def_value_satisfy_parser_fn!(Where, pattern_value_place, PatternValuePlace, PatternValuePlace::from_value);
def_value_satisfy_parser_fn!(Where, pattern_non_value_place, PatternNonValuePlace, PatternNonValuePlace::from_value);
fn period_(input: I) -> ParseResult<(), I> {
def_value_parser_fn!(Where, pattern, Pattern, input, {
satisfy_map(|x: edn::Value| {
if let PlainSymbol(ref s) = x {
if s.0.as_str() == "." {
return Some(());
if let edn::Value::Vector(y) = x {
// While *technically* Datomic allows you to have a query like:
// [:find … :where [[?x]]]
// We don't -- we require at list e, a.
let mut p =
(optional(Query::source_var()), // src
Where::pattern_non_value_place(), // e
Where::pattern_non_value_place(), // a
optional(Where::pattern_value_place()), // v
optional(Where::pattern_non_value_place()), // tx
eof())
.map(|(src, e, a, v, tx, _)| {
let v = v.unwrap_or(PatternValuePlace::Placeholder);
let tx = tx.unwrap_or(PatternNonValuePlace::Placeholder);
// Pattern::new takes care of reversal of reversed
// attributes: [?x :foo/_bar ?y] turns into
// [?y :foo/bar ?x].
Pattern::new(src, e, a, v, tx)
});
// This is a bit messy: the inner conversion to a Pattern can
// fail if the input is something like
//
// ```edn
// [?x :foo/_reversed 23.4]
// ```
//
// because
//
// ```edn
// [23.4 :foo/reversed ?x]
// ```
//
// is nonsense. That leaves us with nested optionals; we unwrap them here.
let r: ParseResult<Option<Pattern>, _> = p.parse_lazy(&y[..]).into();
let v: Option<Option<Pattern>> = r.ok().map(|x| x.0);
v.unwrap_or(None)
} else {
None
}
}
return None;
}).parse_stream(input)
});
def_value_parser_fn!(Where, clauses, Vec<WhereClause>, input, {
// Right now we only support patterns. See #239 for more.
(many1::<Vec<Pattern>, _>(Where::pattern()), eof())
.map(|(patterns, _)| {
patterns.into_iter().map(WhereClause::Pattern).collect()
})
.parse_stream(input)
}
});
fn ellipsis() -> FindSpParser<(), I> {
fn_parser(FindSp::<I>::ellipsis_, "ellipsis")
}
pub struct Find<I>(::std::marker::PhantomData<fn(I) -> I>);
fn ellipsis_(input: I) -> ParseResult<(), I> {
satisfy_map(|x: edn::Value| {
if let PlainSymbol(ref s) = x {
if s.0.as_str() == "..." {
return Some(());
}
}
return None;
})
.parse_stream(input)
}
def_value_parser_fn!(Find, period, (), input, {
matches_plain_symbol!(".", input)
});
fn find_scalar() -> FindSpParser<FindSpec, I> {
fn_parser(FindSp::<I>::find_scalar_, "find_scalar")
}
def_value_parser_fn!(Find, ellipsis, (), input, {
matches_plain_symbol!("...", input)
});
fn find_scalar_(input: I) -> ParseResult<FindSpec, I> {
(FindSp::variable(), FindSp::period(), eof())
def_value_parser_fn!(Find, find_scalar, FindSpec, input, {
(Query::variable(), Find::period(), eof())
.map(|(var, _, _)| FindSpec::FindScalar(Element::Variable(var)))
.parse_stream(input)
}
});
fn find_coll() -> FindSpParser<FindSpec, I> {
fn_parser(FindSp::<I>::find_coll_, "find_coll")
}
fn find_coll_(input: I) -> ParseResult<FindSpec, I> {
def_value_parser_fn!(Find, find_coll, FindSpec, input, {
satisfy_unwrap!(edn::Value::Vector, y, {
let mut p = (FindSp::variable(), FindSp::ellipsis(), eof())
let mut p = (Query::variable(), Find::ellipsis(), eof())
.map(|(var, _, _)| FindSpec::FindColl(Element::Variable(var)));
let r: ParseResult<FindSpec, _> = p.parse_lazy(&y[..]).into();
FindSp::to_parsed_value(r)
Query::to_parsed_value(r)
})
.parse_stream(input)
}
});
fn elements() -> FindSpParser<Vec<Element>, I> {
fn_parser(FindSp::<I>::elements_, "elements")
}
fn elements_(input: I) -> ParseResult<Vec<Element>, I> {
(many1::<Vec<Variable>, _>(FindSp::variable()), eof())
def_value_parser_fn!(Find, elements, Vec<Element>, input, {
(many1::<Vec<Variable>, _>(Query::variable()), eof())
.map(|(vars, _)| {
vars.into_iter()
.map(Element::Variable)
.collect()
})
.parse_stream(input)
}
});
fn find_rel() -> FindSpParser<FindSpec, I> {
fn_parser(FindSp::<I>::find_rel_, "find_rel")
}
def_value_parser_fn!(Find, find_rel, FindSpec, input, {
Find::elements().map(FindSpec::FindRel).parse_stream(input)
});
fn find_rel_(input: I) -> ParseResult<FindSpec, I> {
FindSp::elements().map(FindSpec::FindRel).parse_stream(input)
}
fn find_tuple() -> FindSpParser<FindSpec, I> {
fn_parser(FindSp::<I>::find_tuple_, "find_tuple")
}
fn find_tuple_(input: I) -> ParseResult<FindSpec, I> {
def_value_parser_fn!(Find, find_tuple, FindSpec, input, {
satisfy_unwrap!(edn::Value::Vector, y, {
let r: ParseResult<FindSpec, _> =
FindSp::elements().map(FindSpec::FindTuple).parse_lazy(&y[..]).into();
FindSp::to_parsed_value(r)
Find::elements().map(FindSpec::FindTuple).parse_lazy(&y[..]).into();
Query::to_parsed_value(r)
})
.parse_stream(input)
}
});
fn find() -> FindSpParser<FindSpec, I> {
fn_parser(FindSp::<I>::find_, "find")
}
fn find_(input: I) -> ParseResult<FindSpec, I> {
def_value_parser_fn!(Find, find, FindSpec, input, {
// Any one of the four specs might apply, so we combine them with `choice`.
// Our parsers consume input, so we need to wrap them in `try` so that they
// operate independently.
choice::<[&mut Parser<Input = I, Output = FindSpec>; 4],
_>([&mut try(FindSp::find_scalar()),
&mut try(FindSp::find_coll()),
&mut try(FindSp::find_tuple()),
&mut try(FindSp::find_rel())])
choice::<[&mut Parser<Input = I, Output = FindSpec>; 4], _>
([&mut try(Find::find_scalar()),
&mut try(Find::find_coll()),
&mut try(Find::find_tuple()),
&mut try(Find::find_rel())])
.parse_stream(input)
}
fn to_parsed_value<T>(r: ParseResult<T, I>) -> Option<T> {
r.ok().map(|x| x.0)
}
}
});
// Parse a sequence of values into one of four find specs.
//
@ -172,29 +223,131 @@ impl<I> FindSp<I>
// `?x . ` = FindScalar
// `[?x ?y ?z]` = FindTuple
//
#[allow(dead_code)]
pub fn find_seq_to_find_spec(find: &[edn::Value]) -> FindParseResult {
FindSp::find()
Find::find()
.parse(find)
.map(|x| x.0)
.map_err(|_| FindParseError::Err)
}
#[allow(dead_code)]
pub fn clause_seq_to_patterns(clauses: &[edn::Value]) -> WhereParseResult {
Where::clauses()
.parse(clauses)
.map(|x| x.0)
.map_err(|_| WhereParseError::Err)
}
#[cfg(test)]
mod test {
extern crate combine;
extern crate edn;
extern crate mentat_query;
extern crate ordered_float;
use self::combine::Parser;
use self::mentat_query::{Element, FindSpec, Variable};
use self::ordered_float::OrderedFloat;
use self::mentat_query::{
Element,
FindSpec,
NonIntegerConstant,
Pattern,
PatternNonValuePlace,
PatternValuePlace,
SrcVar,
Variable,
};
use super::*;
#[test]
fn test_pattern_mixed() {
let e = edn::PlainSymbol::new("_");
let a = edn::NamespacedKeyword::new("foo", "bar");
let v = OrderedFloat(99.9);
let tx = edn::PlainSymbol::new("?tx");
let input = [edn::Value::Vector(
vec!(edn::Value::PlainSymbol(e.clone()),
edn::Value::NamespacedKeyword(a.clone()),
edn::Value::Float(v.clone()),
edn::Value::PlainSymbol(tx.clone())))];
assert_parses_to!(Where::pattern, input, Pattern {
source: None,
entity: PatternNonValuePlace::Placeholder,
attribute: PatternNonValuePlace::Ident(a),
value: PatternValuePlace::Constant(NonIntegerConstant::Float(v)),
tx: PatternNonValuePlace::Variable(Variable(tx)),
});
}
#[test]
fn test_pattern_vars() {
let s = edn::PlainSymbol::new("$x");
let e = edn::PlainSymbol::new("?e");
let a = edn::PlainSymbol::new("?a");
let v = edn::PlainSymbol::new("?v");
let tx = edn::PlainSymbol::new("?tx");
let input = [edn::Value::Vector(
vec!(edn::Value::PlainSymbol(s.clone()),
edn::Value::PlainSymbol(e.clone()),
edn::Value::PlainSymbol(a.clone()),
edn::Value::PlainSymbol(v.clone()),
edn::Value::PlainSymbol(tx.clone())))];
assert_parses_to!(Where::pattern, input, Pattern {
source: Some(SrcVar::NamedSrc("x".to_string())),
entity: PatternNonValuePlace::Variable(Variable(e)),
attribute: PatternNonValuePlace::Variable(Variable(a)),
value: PatternValuePlace::Variable(Variable(v)),
tx: PatternNonValuePlace::Variable(Variable(tx)),
});
}
#[test]
fn test_pattern_reversed_invalid() {
let e = edn::PlainSymbol::new("_");
let a = edn::NamespacedKeyword::new("foo", "_bar");
let v = OrderedFloat(99.9);
let tx = edn::PlainSymbol::new("?tx");
let input = [edn::Value::Vector(
vec!(edn::Value::PlainSymbol(e.clone()),
edn::Value::NamespacedKeyword(a.clone()),
edn::Value::Float(v.clone()),
edn::Value::PlainSymbol(tx.clone())))];
let mut par = Where::pattern();
let result = par.parse(&input[..]);
assert!(matches!(result, Err(_)), "Expected a parse error.");
}
#[test]
fn test_pattern_reversed() {
let e = edn::PlainSymbol::new("_");
let a = edn::NamespacedKeyword::new("foo", "_bar");
let v = edn::PlainSymbol::new("?v");
let tx = edn::PlainSymbol::new("?tx");
let input = [edn::Value::Vector(
vec!(edn::Value::PlainSymbol(e.clone()),
edn::Value::NamespacedKeyword(a.clone()),
edn::Value::PlainSymbol(v.clone()),
edn::Value::PlainSymbol(tx.clone())))];
// Note that the attribute is no longer reversed, and the entity and value have
// switched places.
assert_parses_to!(Where::pattern, input, Pattern {
source: None,
entity: PatternNonValuePlace::Variable(Variable(v)),
attribute: PatternNonValuePlace::Ident(edn::NamespacedKeyword::new("foo", "bar")),
value: PatternValuePlace::Placeholder,
tx: PatternNonValuePlace::Variable(Variable(tx)),
});
}
#[test]
fn test_find_sp_variable() {
let sym = edn::PlainSymbol::new("?x");
let input = [edn::Value::PlainSymbol(sym.clone())];
assert_parses_to!(FindSp::variable, input, Variable(sym));
assert_parses_to!(Query::variable, input, Variable(sym));
}
#[test]
@ -202,7 +355,7 @@ mod test {
let sym = edn::PlainSymbol::new("?x");
let period = edn::PlainSymbol::new(".");
let input = [edn::Value::PlainSymbol(sym.clone()), edn::Value::PlainSymbol(period.clone())];
assert_parses_to!(FindSp::find_scalar,
assert_parses_to!(Find::find_scalar,
input,
FindSpec::FindScalar(Element::Variable(Variable(sym))));
}
@ -213,7 +366,7 @@ mod test {
let period = edn::PlainSymbol::new("...");
let input = [edn::Value::Vector(vec![edn::Value::PlainSymbol(sym.clone()),
edn::Value::PlainSymbol(period.clone())])];
assert_parses_to!(FindSp::find_coll,
assert_parses_to!(Find::find_coll,
input,
FindSpec::FindColl(Element::Variable(Variable(sym))));
}
@ -223,7 +376,7 @@ mod test {
let vx = edn::PlainSymbol::new("?x");
let vy = edn::PlainSymbol::new("?y");
let input = [edn::Value::PlainSymbol(vx.clone()), edn::Value::PlainSymbol(vy.clone())];
assert_parses_to!(FindSp::find_rel,
assert_parses_to!(Find::find_rel,
input,
FindSpec::FindRel(vec![Element::Variable(Variable(vx)),
Element::Variable(Variable(vy))]));
@ -235,7 +388,7 @@ mod test {
let vy = edn::PlainSymbol::new("?y");
let input = [edn::Value::Vector(vec![edn::Value::PlainSymbol(vx.clone()),
edn::Value::PlainSymbol(vy.clone())])];
assert_parses_to!(FindSp::find_tuple,
assert_parses_to!(Find::find_tuple,
input,
FindSpec::FindTuple(vec![Element::Variable(Variable(vx)),
Element::Variable(Variable(vy))]));

2
query-parser/src/parser_util.rs
View file

@ -10,6 +10,8 @@
extern crate combine;
extern crate edn;
extern crate mentat_parser_utils;
extern crate mentat_query;
/// Generate a `satisfy_map` expression that matches a `PlainSymbol`

24
query-parser/src/util.rs
View file

@ -9,33 +9,9 @@
// specific language governing permissions and limitations under the License.
extern crate edn;
extern crate mentat_query;
use std::collections::BTreeMap;
use self::mentat_query::{FromValue, Variable};
use super::error::NotAVariableError;
/// If the provided slice of EDN values are all variables as
/// defined by `value_to_variable`, return a Vec of Variables.
/// Otherwise, return the unrecognized Value.
pub fn values_to_variables(vals: &[edn::Value]) -> Result<Vec<Variable>, NotAVariableError> {
let mut out: Vec<Variable> = Vec::with_capacity(vals.len());
for v in vals {
if let Some(var) = Variable::from_value(v) {
out.push(var);
continue;
}
return Err(NotAVariableError(v.clone()));
}
return Ok(out);
}
#[test]
fn test_values_to_variables() {
// TODO
}
/// Take a slice of EDN values, as would be extracted from an
/// `edn::Value::Vector`, and turn it into a map.
///

4
query/Cargo.toml
View file

@ -3,8 +3,8 @@ name = "mentat_query"
version = "0.0.1"
[dependencies]
[dependencies.num] # For EDN value usage.
[dependencies.ordered-float]
num = "0.1.35"
ordered-float = "0.4.0"
[dependencies.edn]
path = "../edn"

185
query/src/lib.rs
View file

@ -60,7 +60,7 @@ impl FromValue<Variable> for Variable {
}
impl Variable {
fn from_symbol(sym: &PlainSymbol) -> Option<Variable> {
pub fn from_symbol(sym: &PlainSymbol) -> Option<Variable> {
if sym.is_var_symbol() {
Some(Variable(sym.clone()))
} else {
@ -118,24 +118,128 @@ pub enum FnArg {
/// This encoding allows us to represent integers that aren't
/// entity IDs. That'll get filtered out in the context of the
/// database.
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum PatternNonValuePlace {
Placeholder,
Variable(Variable),
Entid(u64), // Note unsigned. See #190.
Entid(i64), // Will always be +ve. See #190.
Ident(NamespacedKeyword),
}
impl PatternNonValuePlace {
// I think we'll want move variants, so let's leave these here for now.
#[allow(dead_code)]
fn into_pattern_value_place(self) -> PatternValuePlace {
match self {
PatternNonValuePlace::Placeholder => PatternValuePlace::Placeholder,
PatternNonValuePlace::Variable(x) => PatternValuePlace::Variable(x),
PatternNonValuePlace::Entid(x) => PatternValuePlace::EntidOrInteger(x),
PatternNonValuePlace::Ident(x) => PatternValuePlace::IdentOrKeyword(x),
}
}
fn to_pattern_value_place(&self) -> PatternValuePlace {
match *self {
PatternNonValuePlace::Placeholder => PatternValuePlace::Placeholder,
PatternNonValuePlace::Variable(ref x) => PatternValuePlace::Variable(x.clone()),
PatternNonValuePlace::Entid(x) => PatternValuePlace::EntidOrInteger(x),
PatternNonValuePlace::Ident(ref x) => PatternValuePlace::IdentOrKeyword(x.clone()),
}
}
}
impl FromValue<PatternNonValuePlace> for PatternNonValuePlace {
fn from_value(v: &edn::Value) -> Option<PatternNonValuePlace> {
match v {
&edn::Value::Integer(x) => if x >= 0 {
Some(PatternNonValuePlace::Entid(x))
} else {
None
},
&edn::Value::PlainSymbol(ref x) => if x.0.as_str() == "_" {
Some(PatternNonValuePlace::Placeholder)
} else {
if let Some(v) = Variable::from_symbol(x) {
Some(PatternNonValuePlace::Variable(v))
} else {
None
}
},
&edn::Value::NamespacedKeyword(ref x) =>
Some(PatternNonValuePlace::Ident(x.clone())),
_ => None,
}
}
}
/// The `v` part of a pattern can be much broader: it can represent
/// integers that aren't entity IDs (particularly negative integers),
/// strings, and all the rest. We group those under `Constant`.
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum PatternValuePlace {
Placeholder,
Variable(Variable),
EntidOrInteger(i64),
Ident(NamespacedKeyword),
IdentOrKeyword(NamespacedKeyword),
Constant(NonIntegerConstant),
}
impl FromValue<PatternValuePlace> for PatternValuePlace {
fn from_value(v: &edn::Value) -> Option<PatternValuePlace> {
match v {
&edn::Value::Integer(x) =>
Some(PatternValuePlace::EntidOrInteger(x)),
&edn::Value::PlainSymbol(ref x) if x.0.as_str() == "_" =>
Some(PatternValuePlace::Placeholder),
&edn::Value::PlainSymbol(ref x) if x.is_var_symbol() =>
Some(PatternValuePlace::Variable(Variable(x.clone()))),
&edn::Value::NamespacedKeyword(ref x) =>
Some(PatternValuePlace::IdentOrKeyword(x.clone())),
&edn::Value::Boolean(x) =>
Some(PatternValuePlace::Constant(NonIntegerConstant::Boolean(x))),
&edn::Value::Float(x) =>
Some(PatternValuePlace::Constant(NonIntegerConstant::Float(x))),
&edn::Value::BigInteger(ref x) =>
Some(PatternValuePlace::Constant(NonIntegerConstant::BigInteger(x.clone()))),
&edn::Value::Text(ref x) =>
Some(PatternValuePlace::Constant(NonIntegerConstant::Text(x.clone()))),
_ => None,
}
}
}
impl PatternValuePlace {
// I think we'll want move variants, so let's leave these here for now.
#[allow(dead_code)]
fn into_pattern_non_value_place(self) -> Option<PatternNonValuePlace> {
match self {
PatternValuePlace::Placeholder => Some(PatternNonValuePlace::Placeholder),
PatternValuePlace::Variable(x) => Some(PatternNonValuePlace::Variable(x)),
PatternValuePlace::EntidOrInteger(x) => if x >= 0 {
Some(PatternNonValuePlace::Entid(x))
} else {
None
},
PatternValuePlace::IdentOrKeyword(x) => Some(PatternNonValuePlace::Ident(x)),
PatternValuePlace::Constant(_) => None,
}
}
fn to_pattern_non_value_place(&self) -> Option<PatternNonValuePlace> {
match *self {
PatternValuePlace::Placeholder => Some(PatternNonValuePlace::Placeholder),
PatternValuePlace::Variable(ref x) => Some(PatternNonValuePlace::Variable(x.clone())),
PatternValuePlace::EntidOrInteger(x) => if x >= 0 {
Some(PatternNonValuePlace::Entid(x))
} else {
None
},
PatternValuePlace::IdentOrKeyword(ref x) => Some(PatternNonValuePlace::Ident(x.clone())),
PatternValuePlace::Constant(_) => None,
}
}
}
/*
pub enum PullPattern {
Constant(Constant),
@ -212,13 +316,6 @@ pub enum FindSpec {
FindScalar(Element),
}
#[derive(Clone,Debug,Eq,PartialEq)]
#[allow(dead_code)]
pub struct FindQuery {
pub find_spec: FindSpec,
pub default_source: SrcVar,
}
/// Returns true if the provided `FindSpec` returns at most one result.
pub fn is_unit_limited(spec: &FindSpec) -> bool {
match spec {
@ -255,18 +352,55 @@ pub fn requires_distinct(spec: &FindSpec) -> bool {
// A pattern with a reversed attribute — :foo/_bar — is reversed
// at the point of parsing. These `Pattern` instances only represent
// one direction.
#[allow(dead_code)]
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct Pattern {
source: Option<SrcVar>,
entity: PatternNonValuePlace,
attribute: PatternNonValuePlace,
value: PatternValuePlace,
tx: PatternNonValuePlace,
pub source: Option<SrcVar>,
pub entity: PatternNonValuePlace,
pub attribute: PatternNonValuePlace,
pub value: PatternValuePlace,
pub tx: PatternNonValuePlace,
}
impl Pattern {
pub fn new(src: Option<SrcVar>,
e: PatternNonValuePlace,
a: PatternNonValuePlace,
v: PatternValuePlace,
tx: PatternNonValuePlace) -> Option<Pattern> {
let aa = a.clone(); // Too tired of fighting borrow scope for now.
if let PatternNonValuePlace::Ident(ref k) = aa {
if k.is_backward() {
// e and v have different types; we must convert them.
// Not every parseable value is suitable for the entity field!
// As such, this is a failable constructor.
let e_v = e.to_pattern_value_place();
if let Some(v_e) = v.to_pattern_non_value_place() {
return Some(Pattern {
source: src,
entity: v_e,
attribute: PatternNonValuePlace::Ident(k.to_reversed()),
value: e_v,
tx: tx,
});
} else {
return None;
}
}
}
Some(Pattern {
source: src,
entity: e,
attribute: a,
value: v,
tx: tx,
})
}
}
#[allow(dead_code)]
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum WhereClause {
/*
Not,
NotJoin,
Or,
@ -274,16 +408,17 @@ pub enum WhereClause {
Pred,
WhereFn,
RuleExpr,
*/
Pattern,
Pattern(Pattern),
}
#[allow(dead_code)]
pub struct Query {
find: FindSpec,
with: Vec<Variable>,
in_vars: Vec<Variable>,
in_sources: Vec<SrcVar>,
where_clauses: Vec<WhereClause>,
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct FindQuery {
pub find_spec: FindSpec,
pub default_source: SrcVar,
pub with: Vec<Variable>,
pub in_vars: Vec<Variable>,
pub in_sources: Vec<SrcVar>,
pub where_clauses: Vec<WhereClause>,
// TODO: in_rules;
}