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Add TransactableValue abstracting value places that can be transacted.

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This is a stepping stone to transacting entities that are not based on
`edn::ValueAndSpan`.  We need to turn some value places (general) into
entity places (restricted), and those restrictions are captured in
tx-parser right now.  But for `TypedValue` value places, those
restrictions are encoded in the type itself.  This lays the track to
accept other value types in value places, which is good for
programmatic builder interfaces.
This commit is contained in:
Nick Alexander 2018-05-07 13:55:20 -07:00
parent e1e7cbaa44
commit 4c4af46315
3 changed files with 92 additions and 50 deletions
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47
db/src/internal_types.rs
View file

@ -19,18 +19,63 @@ use mentat_core::KnownEntid;
use mentat_core::util::Either;
use edn::{
ValueAndSpan,
};
use errors;
use errors::ErrorKind;
use errors::{
ErrorKind,
Result,
ResultExt,
};
use schema::{
SchemaTypeChecking,
};
use types::{
AVMap,
AVPair,
Entid,
Schema,
TypedValue,
ValueType,
};
use mentat_tx::entities::{
EntidOrLookupRefOrTempId,
OpType,
TempId,
};
use mentat_tx_parser;
/// The transactor is tied to `edn::ValueAndSpan` right now, but in the future we'd like to support
/// `TypedValue` directly for programmatic use. `TransactableValue` encapsulates the interface
/// value types (i.e., values in the value place) need to support to be transacted.
pub trait TransactableValue {
/// Coerce this value place into the given type. This is where we perform schema-aware
/// coercion, for example coercing an integral value into a ref where appropriate.
fn into_typed_value(self, schema: &Schema, value_type: ValueType) -> Result<TypedValue>;
/// Make an entity place out of this value place. This is where we limit values in nested maps
/// to valid entity places.
fn into_entity_place(self) -> Result<EntidOrLookupRefOrTempId>;
fn as_tempid(&self) -> Option<TempId>;
}
impl TransactableValue for ValueAndSpan {
fn into_typed_value(self, schema: &Schema, value_type: ValueType) -> Result<TypedValue> {
schema.to_typed_value(&self.without_spans(), value_type)
}
fn into_entity_place(self) -> Result<EntidOrLookupRefOrTempId> {
mentat_tx_parser::Tx::parse_entid_or_lookup_ref_or_temp_id(self)
.chain_err(|| ErrorKind::NotYetImplemented("db id error".into()))
}
fn as_tempid(&self) -> Option<TempId> {
self.inner.as_text().cloned().map(TempId::External)
}
}
#[derive(Clone, Debug, Eq, Hash, Ord, PartialOrd, PartialEq)]
pub enum Term<E, V> {

64
db/src/tx.rs
View file

@ -82,6 +82,7 @@ use internal_types::{
TermWithTempIds,
TermWithTempIdsAndLookupRefs,
TermWithoutTempIds,
TransactableValue,
TypedValueOr,
replace_lookup_ref,
};
@ -105,7 +106,6 @@ use mentat_tx::entities::{
OpType,
TempId,
};
use mentat_tx_parser;
use metadata;
use rusqlite;
use schema::{
@ -161,6 +161,29 @@ pub struct Tx<'conn, 'a, W> where W: TransactWatcher {
tx_instant: Option<DateTime<Utc>>,
}
/// Remove any :db/id value from the given map notation, converting the returned value into
/// something suitable for the entity position rather than something suitable for a value position.
pub fn remove_db_id(map: &mut entmod::MapNotation) -> Result<Option<entmod::EntidOrLookupRefOrTempId>> {
// TODO: extract lazy defined constant.
let db_id_key = entmod::Entid::Ident(NamespacedKeyword::new("db", "id"));
let db_id: Option<entmod::EntidOrLookupRefOrTempId> = if let Some(id) = map.remove(&db_id_key) {
match id {
entmod::AtomOrLookupRefOrVectorOrMapNotation::Atom(v) => Some(v.into_entity_place()?),
entmod::AtomOrLookupRefOrVectorOrMapNotation::LookupRef(_) |
entmod::AtomOrLookupRefOrVectorOrMapNotation::TxFunction(_) |
entmod::AtomOrLookupRefOrVectorOrMapNotation::Vector(_) |
entmod::AtomOrLookupRefOrVectorOrMapNotation::MapNotation(_) => {
bail!(ErrorKind::NotYetImplemented("db id error".into()))
},
}
} else {
None
};
Ok(db_id)
}
impl<'conn, 'a, W> Tx<'conn, 'a, W> where W: TransactWatcher {
pub fn new(
store: &'conn rusqlite::Connection,
@ -340,18 +363,19 @@ impl<'conn, 'a, W> Tx<'conn, 'a, W> where W: TransactWatcher {
}
match x {
entmod::AtomOrLookupRefOrVectorOrMapNotation::Atom(ref v) => {
entmod::AtomOrLookupRefOrVectorOrMapNotation::Atom(v) => {
// Here is where we do schema-aware typechecking: we either assert
// that the given value is in the attribute's value set, or (in
// limited cases) coerce the value into the attribute's value set.
if let Some(text) = v.inner.as_text() {
Ok(Either::Right(LookupRefOrTempId::TempId(self.intern_temp_id(TempId::External(text.clone())))))
} else {
if let TypedValue::Ref(entid) = self.schema.to_typed_value(&v.clone().without_spans(), ValueType::Ref)? {
Ok(Either::Left(KnownEntid(entid)))
} else {
// The given value is expected to be :db.type/ref, so this shouldn't happen.
bail!(ErrorKind::NotYetImplemented(format!("Cannot use :attr/_reversed notation for attribute {} with value that is not :db.valueType :db.type/ref", forward_a)))
match v.as_tempid() {
Some(tempid) => Ok(Either::Right(LookupRefOrTempId::TempId(self.intern_temp_id(tempid)))),
None => {
if let TypedValue::Ref(entid) = v.into_typed_value(&self.schema, ValueType::Ref)? {
Ok(Either::Left(KnownEntid(entid)))
} else {
// The given value is expected to be :db.type/ref, so this shouldn't happen.
bail!(ErrorKind::NotYetImplemented(format!("Cannot use :attr/_reversed notation for attribute {} with value that is not :db.valueType :db.type/ref", forward_a)))
}
}
}
},
@ -392,7 +416,7 @@ impl<'conn, 'a, W> Tx<'conn, 'a, W> where W: TransactWatcher {
Entity::MapNotation(mut map_notation) => {
// :db/id is optional; if it's not given, we generate a special internal tempid
// to use for upserting. This tempid will not be reported in the TxReport.
let db_id: entmod::EntidOrLookupRefOrTempId = mentat_tx_parser::remove_db_id(&mut map_notation)?.unwrap_or_else(|| in_process.allocate_mentat_id());
let db_id: entmod::EntidOrLookupRefOrTempId = remove_db_id(&mut map_notation)?.unwrap_or_else(|| in_process.allocate_mentat_id());
// We're not nested, so :db/isComponent is not relevant. We just explode the
// map notation.
@ -418,14 +442,16 @@ impl<'conn, 'a, W> Tx<'conn, 'a, W> where W: TransactWatcher {
let v = match v {
entmod::AtomOrLookupRefOrVectorOrMapNotation::Atom(v) => {
if attribute.value_type == ValueType::Ref && v.inner.is_text() {
Either::Right(LookupRefOrTempId::TempId(in_process.intern_temp_id(v.inner.as_text().cloned().map(TempId::External).unwrap())))
// Here is where we do schema-aware typechecking: we either assert
// that the given value is in the attribute's value set, or (in
// limited cases) coerce the value into the attribute's value set.
if attribute.value_type == ValueType::Ref {
match v.as_tempid() {
Some(tempid) => Either::Right(LookupRefOrTempId::TempId(in_process.intern_temp_id(tempid))),
None => v.into_typed_value(&self.schema, attribute.value_type).map(Either::Left)?,
}
} else {
// Here is where we do schema-aware typechecking: we either assert that
// the given value is in the attribute's value set, or (in limited
// cases) coerce the value into the attribute's value set.
let typed_value: TypedValue = self.schema.to_typed_value(&v.without_spans(), attribute.value_type)?;
Either::Left(typed_value)
v.into_typed_value(&self.schema, attribute.value_type).map(Either::Left)?
}
},
@ -488,7 +514,7 @@ impl<'conn, 'a, W> Tx<'conn, 'a, W> where W: TransactWatcher {
// :db/id is optional; if it's not given, we generate a special internal tempid
// to use for upserting. This tempid will not be reported in the TxReport.
let db_id: Option<entmod::EntidOrLookupRefOrTempId> = mentat_tx_parser::remove_db_id(&mut map_notation)?;
let db_id: Option<entmod::EntidOrLookupRefOrTempId> = remove_db_id(&mut map_notation)?;
let mut dangling = db_id.is_none();
let db_id: entmod::EntidOrLookupRefOrTempId = db_id.unwrap_or_else(|| in_process.allocate_mentat_id());

31
tx-parser/src/lib.rs
View file

@ -177,7 +177,7 @@ impl<'a> Tx<'a> {
.map_err(|e| Error::from_kind(ErrorKind::ParseError(e.into())))
}
fn parse_entid_or_lookup_ref_or_temp_id(input: edn::ValueAndSpan) -> std::result::Result<EntidOrLookupRefOrTempId, errors::Error> {
pub fn parse_entid_or_lookup_ref_or_temp_id(input: edn::ValueAndSpan) -> std::result::Result<EntidOrLookupRefOrTempId, errors::Error> {
Tx::entid_or_lookup_ref_or_temp_id()
.skip(eof())
.parse(input.atom_stream())
@ -186,35 +186,6 @@ impl<'a> Tx<'a> {
}
}
/// Remove any :db/id value from the given map notation, converting the returned value into
/// something suitable for the entity position rather than something suitable for a value position.
///
/// This is here simply to not expose some of the internal APIs of the tx-parser.
pub fn remove_db_id(map: &mut MapNotation) -> std::result::Result<Option<EntidOrLookupRefOrTempId>, errors::Error> {
// TODO: extract lazy defined constant.
let db_id_key = Entid::Ident(edn::NamespacedKeyword::new("db", "id"));
let db_id: Option<EntidOrLookupRefOrTempId> = if let Some(id) = map.remove(&db_id_key) {
match id {
AtomOrLookupRefOrVectorOrMapNotation::Atom(v) => {
let db_id = Tx::parse_entid_or_lookup_ref_or_temp_id(v)
.chain_err(|| Error::from(ErrorKind::DbIdError))?;
Some(db_id)
},
AtomOrLookupRefOrVectorOrMapNotation::LookupRef(_) |
AtomOrLookupRefOrVectorOrMapNotation::TxFunction(_) |
AtomOrLookupRefOrVectorOrMapNotation::Vector(_) |
AtomOrLookupRefOrVectorOrMapNotation::MapNotation(_) => {
bail!(ErrorKind::DbIdError)
},
}
} else {
None
};
Ok(db_id)
}
#[cfg(test)]
mod tests {
use super::*;