Addressed Review comments rnewman.

* Use better grammar in comments.
* Test for which error returned from `not-join` validation.

parser-utils/src/lib.rs

@@ -38,8 +38,20 @@ pub type ResultParser<O, I> = Expected<FnParser<I, fn(I) -> ParseResult<O, I>>>;
 #[macro_export]
 macro_rules! assert_parses_to {
     ( $parser: expr, $input: expr, $expected: expr ) => {{
-        let mut par = $parser();
-        let result = par.parse($input.with_spans().into_atom_stream()).map(|x| x.0); // TODO: check remainder of stream.
+        let par = $parser();
+        let result = par.skip(eof()).parse($input.with_spans().into_atom_stream()).map(|x| x.0);
+        assert_eq!(result, Ok($expected));
+    }}
+}
+
+/// `assert_edn_parses_to!` simplifies some of the boilerplate around running a parser function
+/// against string input and expecting a certain result.
+#[macro_export]
+macro_rules! assert_edn_parses_to {
+    ( $parser: expr, $input: expr, $expected: expr ) => {{
+        let par = $parser();
+        let input = edn::parse::value($input).expect("to be able to parse input as EDN");
+        let result = par.skip(eof()).parse(input.into_atom_stream()).map(|x| x.0);
         assert_eq!(result, Ok($expected));
     }}
 }

query-algebrizer/src/clauses/mod.rs

@@ -56,11 +56,15 @@ use types::{
 };
 
 mod or;
+mod not;
 mod pattern;
 mod predicate;
 mod resolve;
 
-use validate::validate_or_join;
+use validate::{
+    validate_not_join,
+    validate_or_join,
+};
 
 // We do this a lot for errors.
 trait RcCloned<T> {
@@ -96,6 +100,7 @@ fn unit_type_set(t: ValueType) -> HashSet<ValueType> {
 ///
 /// - Ordinary pattern clauses turn into `FROM` parts and `WHERE` parts using `=`.
 /// - Predicate clauses turn into the same, but with other functions.
+/// - Function clauses turn `WHERE` parts using function-specific comparisons.
 /// - `not` turns into `NOT EXISTS` with `WHERE` clauses inside the subquery to
 ///   bind it to the outer variables, or adds simple `WHERE` clauses to the outer
 ///   clause.
@@ -581,11 +586,17 @@ impl ConjoiningClauses {
             WhereClause::Pred(p) => {
                 self.apply_predicate(schema, p)
             },
+            WhereClause::WhereFn(f) => {
+                self.apply_where_fn(schema, f)
+            },
             WhereClause::OrJoin(o) => {
                 validate_or_join(&o)
                 //?;
                 //self.apply_or_join(schema, o)
             },
+            WhereClause::NotJoin(n) => {
+                validate_not_join(&n)
+            },
             _ => unimplemented!(),
         }
     }
@@ -606,4 +617,4 @@ fn add_attribute(schema: &mut Schema, e: Entid, a: Attribute) {
 #[cfg(test)]
 pub fn ident(ns: &str, name: &str) -> PatternNonValuePlace {
     PatternNonValuePlace::Ident(::std::rc::Rc::new(NamespacedKeyword::new(ns, name)))
-}
+}

query-algebrizer/src/clauses/pattern.rs

@@ -8,8 +8,6 @@
 // CONDITIONS OF ANY KIND, either express or implied. See the License for the
 // specific language governing permissions and limitations under the License.
 
-use std::rc::Rc;
-
 use mentat_core::{
     Schema,
     TypedValue,
@@ -268,6 +266,7 @@ mod testing {
     use super::*;
 
     use std::collections::BTreeMap;
+    use std::rc::Rc;
 
     use mentat_core::attribute::Unique;
     use mentat_core::{

query-algebrizer/src/clauses/predicate.rs

@@ -10,35 +10,48 @@
 
 use mentat_core::{
     Schema,
+    TypedValue,
+    ValueType,
 };
 
 use mentat_query::{
+    Binding,
+    FnArg,
+    NonIntegerConstant,
     Predicate,
+    SrcVar,
+    VariableOrPlaceholder,
+    WhereFn,
 };
 
 use clauses::ConjoiningClauses;
 
 use errors::{
-    Result,
+    Error,
     ErrorKind,
+    Result,
 };
 
 use types::{
     ColumnConstraint,
+    DatomsColumn,
+    DatomsTable,
+    FulltextColumn,
+    FulltextQualifiedAlias,
     NumericComparison,
+    QualifiedAlias,
+    QueryValue,
 };
 
 /// Application of predicates.
 impl ConjoiningClauses {
-    /// There are several kinds of predicates/functions in our Datalog:
+    /// There are several kinds of predicates in our Datalog:
     /// - A limited set of binary comparison operators: < > <= >= !=.
     ///   These are converted into SQLite binary comparisons and some type constraints.
-    /// - A set of predicates like `fulltext` and `get-else` that are translated into
-    ///   SQL `MATCH`es or joins, yielding bindings.
     /// - In the future, some predicates that are implemented via function calls in SQLite.
     ///
     /// At present we have implemented only the five built-in comparison binary operators.
-    pub fn apply_predicate<'s, 'p>(&mut self, schema: &'s Schema, predicate: Predicate) -> Result<()> {
+    pub fn apply_predicate<'s>(&mut self, schema: &'s Schema, predicate: Predicate) -> Result<()> {
         // Because we'll be growing the set of built-in predicates, handling each differently,
         // and ultimately allowing user-specified predicates, we match on the predicate name first.
         if let Some(op) = NumericComparison::from_datalog_operator(predicate.operator.0.as_str()) {
@@ -53,7 +66,7 @@ impl ConjoiningClauses {
     /// - Ensures that the predicate functions name a known operator.
     /// - Accumulates a `NumericInequality` constraint into the `wheres` list.
     #[allow(unused_variables)]
-    pub fn apply_numeric_predicate<'s, 'p>(&mut self, schema: &'s Schema, comparison: NumericComparison, predicate: Predicate) -> Result<()> {
+    pub fn apply_numeric_predicate<'s>(&mut self, schema: &'s Schema, comparison: NumericComparison, predicate: Predicate) -> Result<()> {
         if predicate.args.len() != 2 {
             bail!(ErrorKind::InvalidNumberOfArguments(predicate.operator.clone(), predicate.args.len(), 2));
         }
@@ -81,6 +94,161 @@ impl ConjoiningClauses {
         self.wheres.add_intersection(constraint);
         Ok(())
     }
+
+
+    /// There are several kinds of functions binding variables in our Datalog:
+    /// - A set of functions like `fulltext` and `get-else` that are translated into
+    ///   SQL `MATCH`es or joins, yielding bindings.
+    /// - In the future, some functions that are implemented via function calls in SQLite.
+    ///
+    /// At present we have implemented only the `fulltext` operator.
+    pub fn apply_where_fn<'s>(&mut self, schema: &'s Schema, where_fn: WhereFn) -> Result<()> {
+        // Because we'll be growing the set of built-in functions, handling each differently, and
+        // ultimately allowing user-specified functions, we match on the function name first.
+        match where_fn.operator.0.as_str() {
+            "fulltext" => self.apply_fulltext(schema, where_fn),
+            _ => bail!(ErrorKind::UnknownFunction(where_fn.operator.clone())),
+        }
+    }
+
+    /// This function:
+    /// - Resolves variables and converts types to those more amenable to SQL.
+    /// - Ensures that the predicate functions name a known operator.
+    /// - Accumulates a `NumericInequality` constraint into the `wheres` list.
+    #[allow(unused_variables)]
+    pub fn apply_fulltext<'s>(&mut self, schema: &'s Schema, where_fn: WhereFn) -> Result<()> {
+        if where_fn.args.len() != 3 {
+            bail!(ErrorKind::InvalidNumberOfArguments(where_fn.operator.clone(), where_fn.args.len(), 3));
+        }
+
+        // TODO: binding-specific error messages.
+        let mut bindings = match where_fn.binding {
+            Binding::BindRel(bindings) => {
+                if bindings.len() > 4 {
+                    bail!(ErrorKind::InvalidNumberOfArguments(where_fn.operator.clone(), bindings.len(), 4));
+                }
+                bindings.into_iter()
+            },
+            _ => bail!(ErrorKind::InvalidArgument(where_fn.operator.clone(), "bindings".into(), 999)),
+        };
+
+        // Go from arguments -- parser output -- to columns or values.
+        // Any variables that aren't bound by this point in the linear processing of clauses will
+        // cause the application of the predicate to fail.
+        let mut args = where_fn.args.into_iter();
+
+        // TODO: process source variables.
+        match args.next().unwrap() {
+            FnArg::SrcVar(SrcVar::DefaultSrc) => {},
+            _ => bail!(ErrorKind::InvalidArgument(where_fn.operator.clone(), "source variable".into(), 0)),
+        }
+
+        // TODO: accept placeholder and set of attributes.  Alternately, consider putting the search
+        // term before the attribute arguments and collect the (variadic) attributes into a set.
+        // let a: Entid  = self.resolve_attribute_argument(&where_fn.operator, 1, args.next().unwrap())?;
+        //
+        // TODO: allow non-constant attributes.
+        // TODO: improve the expression of this matching, possibly by using attribute_for_* uniformly.
+        let a = match args.next().unwrap() {
+            FnArg::Ident(i) => schema.get_entid(&i),
+            // Must be an entid.
+            FnArg::EntidOrInteger(e) => Some(e),
+            _ => None,
+        };
+
+        let a = a.ok_or(ErrorKind::InvalidArgument(where_fn.operator.clone(), "attribute".into(), 1))?;
+        let attribute = schema.attribute_for_entid(a).cloned().ok_or(ErrorKind::InvalidArgument(where_fn.operator.clone(), "attribute".into(), 1))?;
+
+        let fulltext_values = DatomsTable::FulltextValues;
+        let datoms_table = DatomsTable::Datoms;
+
+        let fulltext_values_alias = (self.aliaser)(fulltext_values);
+        let datoms_table_alias = (self.aliaser)(datoms_table);
+
+        // TODO: constrain types in more general cases?
+        self.constrain_attribute(datoms_table_alias.clone(), a);
+
+        self.wheres.add_intersection(ColumnConstraint::Equals(
+            QualifiedAlias(datoms_table_alias.clone(), DatomsColumn::Value),
+            QueryValue::FulltextColumn(FulltextQualifiedAlias(fulltext_values_alias.clone(), FulltextColumn::Rowid))));
+
+        // search is either text or a variable.
+        // TODO: should this just use `resolve_argument`?  Should it add a new `resolve_*` function?
+        let search = match args.next().unwrap() {
+            FnArg::Variable(var) => {
+                self.column_bindings
+                    .get(&var)
+                    .and_then(|cols| cols.first().map(|col| QueryValue::Column(col.clone())))
+                    .ok_or_else(|| Error::from_kind(ErrorKind::UnboundVariable(var.name())))?
+            },
+            FnArg::Constant(NonIntegerConstant::Text(s)) => {
+                QueryValue::TypedValue(TypedValue::typed_string(s.as_str()))
+            },
+            _ => bail!(ErrorKind::InvalidArgument(where_fn.operator.clone(), "string".into(), 2)),
+        };
+
+        // TODO: should we build the FQA in ::Matches, preventing nonsense like matching on ::Rowid?
+        let constraint = ColumnConstraint::Matches(FulltextQualifiedAlias(fulltext_values_alias.clone(), FulltextColumn::Text), search);
+        self.wheres.add_intersection(constraint);
+
+        if let Some(VariableOrPlaceholder::Variable(var)) = bindings.next() {
+            // TODO: can we just check for late binding here?
+            // Do we have, or will we have, an external binding for this variable?
+            if self.bound_value(&var).is_some() || self.input_variables.contains(&var) {
+                // That's a paddlin'!
+                bail!(ErrorKind::InvalidArgument(where_fn.operator.clone(), "illegal bound variable".into(), 999))
+            }
+            self.constrain_var_to_type(var.clone(), ValueType::Ref);
+
+            let entity_alias = QualifiedAlias(datoms_table_alias.clone(), DatomsColumn::Entity);
+            self.column_bindings.entry(var).or_insert(vec![]).push(entity_alias);
+        }
+
+        if let Some(VariableOrPlaceholder::Variable(var)) = bindings.next() {
+            // TODO: can we just check for late binding here?
+            // Do we have, or will we have, an external binding for this variable?
+            if self.bound_value(&var).is_some() || self.input_variables.contains(&var) {
+                // That's a paddlin'!
+                bail!(ErrorKind::InvalidArgument(where_fn.operator.clone(), "illegal bound variable".into(), 999))
+            }
+            self.constrain_var_to_type(var.clone(), ValueType::String);
+
+            // TODO: figure out how to represent a FulltextQualifiedAlias.
+            // let value_alias = FulltextQualifiedAlias(fulltext_values_alias.clone(), FulltextColumn::Text);
+            // self.column_bindings.entry(var).or_insert(vec![]).push(value_alias);
+        }
+
+        if let Some(VariableOrPlaceholder::Variable(var)) = bindings.next() {
+            // TODO: can we just check for late binding here?
+            // Do we have, or will we have, an external binding for this variable?
+            if self.bound_value(&var).is_some() || self.input_variables.contains(&var) {
+                // That's a paddlin'!
+                bail!(ErrorKind::InvalidArgument(where_fn.operator.clone(), "illegal bound variable".into(), 999))
+            }
+            self.constrain_var_to_type(var.clone(), ValueType::Ref);
+
+            let tx_alias = QualifiedAlias(datoms_table_alias.clone(), DatomsColumn::Tx);
+            self.column_bindings.entry(var).or_insert(vec![]).push(tx_alias);
+        }
+
+        if let Some(VariableOrPlaceholder::Variable(var)) = bindings.next() {
+            // TODO: can we just check for late binding here?
+            // Do we have, or will we have, an external binding for this variable?
+            if self.bound_value(&var).is_some() || self.input_variables.contains(&var) {
+                // That's a paddlin'!
+                bail!(ErrorKind::InvalidArgument(where_fn.operator.clone(), "illegal bound variable".into(), 999))
+            }
+            self.constrain_var_to_type(var.clone(), ValueType::Double);
+
+            // TODO: produce this using SQLite's matchinfo.
+            self.value_bindings.insert(var.clone(), TypedValue::Double(0.0.into()));
+
+            // TODO: figure out how to represent a constant binding.
+            // self.column_bindings.entry(var).or_insert(vec![]).push(score_alias);
+        }
+
+        Ok(())
+    }
 }
 
 #[cfg(test)]
@@ -88,6 +256,8 @@ mod testing {
     use super::*;
 
     use std::collections::HashSet;
+    use std::rc::Rc;
+
     use mentat_core::attribute::Unique;
     use mentat_core::{
         Attribute,
@@ -96,13 +266,16 @@ mod testing {
     };
 
     use mentat_query::{
+        Binding,
         FnArg,
         NamespacedKeyword,
         Pattern,
         PatternNonValuePlace,
         PatternValuePlace,
         PlainSymbol,
+        SrcVar,
         Variable,
+        VariableOrPlaceholder,
     };
 
     use clauses::{
@@ -229,4 +402,68 @@ mod testing {
                                                                                       .collect(),
                                               ValueType::String));
     }
-}
+
+    #[test]
+    fn test_apply_fulltext() {
+        let mut cc = ConjoiningClauses::default();
+        let mut schema = Schema::default();
+
+        associate_ident(&mut schema, NamespacedKeyword::new("foo", "fts"), 100);
+        add_attribute(&mut schema, 100, Attribute {
+            value_type: ValueType::String,
+            index: true,
+            fulltext: true,
+            ..Default::default()
+        });
+
+        let op = PlainSymbol::new("fulltext");
+        cc.apply_fulltext(&schema, WhereFn {
+            operator: op,
+            args: vec![
+                FnArg::SrcVar(SrcVar::DefaultSrc),
+                FnArg::Ident(NamespacedKeyword::new("foo", "fts")),
+                FnArg::Constant(NonIntegerConstant::Text(Rc::new("needle".into()))),
+            ],
+            binding: Binding::BindRel(vec![VariableOrPlaceholder::Variable(Variable::from_valid_name("?entity")),
+                                           VariableOrPlaceholder::Variable(Variable::from_valid_name("?value")),
+                                           VariableOrPlaceholder::Variable(Variable::from_valid_name("?tx")),
+                                           VariableOrPlaceholder::Variable(Variable::from_valid_name("?score"))]),
+        }).expect("to be able to apply_fulltext");
+
+        assert!(!cc.is_known_empty);
+
+        // Finally, expand column bindings.
+        cc.expand_column_bindings();
+        assert!(!cc.is_known_empty);
+
+        let clauses = cc.wheres;
+        assert_eq!(clauses.len(), 3);
+
+        assert_eq!(clauses.0[0], ColumnConstraint::Equals(QualifiedAlias("datoms01".to_string(), DatomsColumn::Attribute),
+                                                          QueryValue::Entid(100)).into());
+        assert_eq!(clauses.0[1], ColumnConstraint::Equals(QualifiedAlias("datoms01".to_string(), DatomsColumn::Value),
+                                                          QueryValue::FulltextColumn(FulltextQualifiedAlias("fulltext_values00".to_string(), FulltextColumn::Rowid))).into());
+        assert_eq!(clauses.0[2], ColumnConstraint::Matches(FulltextQualifiedAlias("fulltext_values00".to_string(), FulltextColumn::Text),
+                                                           QueryValue::TypedValue(TypedValue::String(Rc::new("needle".into())))).into());
+
+        let bindings = cc.column_bindings;
+        assert_eq!(bindings.len(), 2);
+
+        assert_eq!(bindings.get(&Variable::from_valid_name("?entity")).expect("column binding for ?entity").clone(),
+                   vec![QualifiedAlias("datoms01".to_string(), DatomsColumn::Entity)]);
+        assert_eq!(bindings.get(&Variable::from_valid_name("?tx")).expect("column binding for ?tx").clone(),
+                   vec![QualifiedAlias("datoms01".to_string(), DatomsColumn::Tx)]);
+
+        let known_types = cc.known_types;
+        assert_eq!(known_types.len(), 4);
+
+        assert_eq!(known_types.get(&Variable::from_valid_name("?entity")).expect("known types for ?entity").clone(),
+                   vec![ValueType::Ref].into_iter().collect());
+        assert_eq!(known_types.get(&Variable::from_valid_name("?value")).expect("known types for ?value").clone(),
+                   vec![ValueType::String].into_iter().collect());
+        assert_eq!(known_types.get(&Variable::from_valid_name("?tx")).expect("known types for ?tx").clone(),
+                   vec![ValueType::Ref].into_iter().collect());
+        assert_eq!(known_types.get(&Variable::from_valid_name("?score")).expect("known types for ?score").clone(),
+                   vec![ValueType::Double].into_iter().collect());
+    }
+}

query-algebrizer/src/clauses/resolve.rs

@@ -56,7 +56,7 @@ impl ConjoiningClauses {
             Constant(NonIntegerConstant::Text(_)) |
             Constant(NonIntegerConstant::BigInteger(_)) => {
                 self.mark_known_empty(EmptyBecause::NonNumericArgument);
-                bail!(ErrorKind::NonNumericArgument(function.clone(), position));
+                bail!(ErrorKind::InvalidArgument(function.clone(), "numeric".into(), position));
             },
             Constant(NonIntegerConstant::Float(f)) => Ok(QueryValue::TypedValue(TypedValue::Double(f))),
         }

query-algebrizer/src/errors.rs

@@ -35,9 +35,9 @@ error_chain! {
             display("unbound variable: {}", name)
         }
 
-        NonNumericArgument(function: PlainSymbol, position: usize) {
+        InvalidArgument(function: PlainSymbol, expected_type: String, position: usize) {
             description("invalid argument")
-            display("invalid argument to {}: expected numeric in position {}.", function, position)
+            display("invalid argument to {}: expected {} in position {}.", function, expected_type, position)
         }
 
         NonMatchingVariablesInOrClause {
@@ -45,6 +45,12 @@ error_chain! {
             description("non-matching variables in 'or' clause")
             display("non-matching variables in 'or' clause")
         }
+
+        NonMatchingVariablesInNotClause {
+            // TODO: flesh out.
+            description("non-matching variables in 'not' clause")
+            display("non-matching variables in 'not' clause")
+        }
     }
 }
 

query-algebrizer/src/lib.rs

@@ -99,6 +99,8 @@ pub use types::{
     ColumnIntersection,
     DatomsColumn,
     DatomsTable,
+    FulltextColumn,
+    FulltextQualifiedAlias,
     QualifiedAlias,
     QueryValue,
     SourceAlias,

query-algebrizer/src/types.rs

@@ -71,6 +71,23 @@ impl DatomsColumn {
     }
 }
 
+/// One of the named columns of our fulltext values table.
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub enum FulltextColumn {
+    Rowid,
+    Text,
+}
+
+impl FulltextColumn {
+    pub fn as_str(&self) -> &'static str {
+        use self::FulltextColumn::*;
+        match *self {
+            Rowid => "rowid",
+            Text => "text",
+        }
+    }
+}
+
 /// A specific instance of a table within a query. E.g., "datoms123".
 pub type TableAlias = String;
 
@@ -94,6 +111,16 @@ impl Debug for QualifiedAlias {
     }
 }
 
+/// A particular column of a particular aliased fulltext table. E.g., "fulltext_values123", Rowid.
+#[derive(PartialEq, Eq, Clone)]
+pub struct FulltextQualifiedAlias(pub TableAlias, pub FulltextColumn);
+
+impl Debug for FulltextQualifiedAlias {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        write!(f, "{}.{}", self.0, self.1.as_str())
+    }
+}
+
 impl QualifiedAlias {
     pub fn for_type_tag(&self) -> QualifiedAlias {
         QualifiedAlias(self.0.clone(), DatomsColumn::ValueTypeTag)
@@ -103,6 +130,7 @@ impl QualifiedAlias {
 #[derive(PartialEq, Eq)]
 pub enum QueryValue {
     Column(QualifiedAlias),
+    FulltextColumn(FulltextQualifiedAlias),
     Entid(Entid),
     TypedValue(TypedValue),
 
@@ -120,6 +148,9 @@ impl Debug for QueryValue {
             &Column(ref qa) => {
                 write!(f, "{:?}", qa)
             },
+            &FulltextColumn(ref qa) => {
+                write!(f, "{:?}", qa)
+            },
             &Entid(ref entid) => {
                 write!(f, "entity({:?})", entid)
             },
@@ -192,6 +223,9 @@ pub enum ColumnConstraint {
         right: QueryValue,
     },
     HasType(TableAlias, ValueType),
+    // TODO: Merge this with NumericInequality?  I expect the fine-grained information to be
+    // valuable when optimizing.
+    Matches(FulltextQualifiedAlias, QueryValue),
 }
 
 #[derive(PartialEq, Eq, Debug)]
@@ -290,6 +324,10 @@ impl Debug for ColumnConstraint {
                 write!(f, "{:?} {:?} {:?}", left, operator, right)
             },
 
+            &Matches(ref qa, ref thing) => {
+                write!(f, "{:?} MATCHES {:?}", qa, thing)
+            },
+
             &HasType(ref qa, value_type) => {
                 write!(f, "{:?}.value_type_tag = {:?}", qa, value_type)
             },
@@ -301,6 +339,7 @@ impl Debug for ColumnConstraint {
 pub enum EmptyBecause {
     // Var, existing, desired.
     TypeMismatch(Variable, HashSet<ValueType>, ValueType),
+    NonAttributeArgument,
     NonNumericArgument,
     NonStringFulltextValue,
     UnresolvedIdent(NamespacedKeyword),
@@ -319,6 +358,9 @@ impl Debug for EmptyBecause {
                 write!(f, "Type mismatch: {:?} can't be {:?}, because it's already {:?}",
                        var, desired, existing)
             },
+            &NonAttributeArgument => {
+                write!(f, "Non-attribute argument in attribute place")
+            },
             &NonNumericArgument => {
                 write!(f, "Non-numeric argument in numeric place")
             },
@@ -346,4 +388,4 @@ impl Debug for EmptyBecause {
             },
         }
     }
-}
+}

query-algebrizer/src/validate.rs

@@ -13,6 +13,7 @@ use std::collections::BTreeSet;
 use mentat_query::{
     ContainsVariables,
     OrJoin,
+    NotJoin,
     Variable,
     UnifyVars,
 };
@@ -74,6 +75,23 @@ pub fn validate_or_join(or_join: &OrJoin) -> Result<()> {
     }
 }
 
+pub fn validate_not_join(not_join: &NotJoin) -> Result<()> {
+    // Grab our mentioned variables and ensure that the rules are followed.
+    match not_join.unify_vars {
+        UnifyVars::Implicit => {
+            Ok(())
+        },
+        UnifyVars::Explicit(ref vars) => {
+            // The joined vars must each appear somewhere in the clauses' mentioned variables.
+            let var_set: BTreeSet<Variable> = vars.iter().cloned().collect();
+            if !var_set.is_subset(&not_join.collect_mentioned_variables()) {
+                bail!(ErrorKind::NonMatchingVariablesInNotClause);
+            }
+            Ok(())
+        },
+    }
+}
+
 #[cfg(test)]
 mod tests {
     extern crate mentat_core;
@@ -95,8 +113,16 @@ mod tests {
     use self::mentat_query_parser::parse_find_string;
 
     use clauses::ident;
+    
+    use errors::{
+        Error,
+        ErrorKind,
+    };
 
-    use super::validate_or_join;
+    use super::{
+        validate_not_join,
+        validate_or_join,
+    };
 
     fn value_ident(ns: &str, name: &str) -> PatternValuePlace {
         PatternValuePlace::IdentOrKeyword(::std::rc::Rc::new(NamespacedKeyword::new(ns, name)))
@@ -229,4 +255,131 @@ mod tests {
             _ => panic!(),
         };
     }
+
+
+    /// Tests that the top-level form is a valid `not`, returning the clauses.
+    fn valid_not_join(parsed: FindQuery, expected_unify: UnifyVars) -> Vec<WhereClause> {
+        // Filter out all the clauses that are not `not`s.
+        let mut nots = parsed.where_clauses.into_iter().filter(|x| match x {
+            &WhereClause::NotJoin(_) => true,
+            _ => false,
+        });
+
+        // There should be only one not clause.
+        let clause = nots.next().unwrap();
+        assert_eq!(None, nots.next());
+
+        match clause {
+            WhereClause::NotJoin(not_join) => {
+                // It's valid: the variables are the same in each branch.
+                assert_eq!((), validate_not_join(&not_join).unwrap());
+                assert_eq!(expected_unify, not_join.unify_vars);
+                not_join.clauses
+            },
+            _ => panic!(),
+        }
+    }
+
+    /// Test that a `not` is valid if it is implicit.
+    #[test]
+    fn test_success_not() {
+        let query = r#"[:find ?name
+                        :where [?id :artist/name ?name]
+                            (not [?id :artist/country :country/CA]
+                                 [?id :artist/country :country/GB])]"#;
+        let parsed = parse_find_string(query).expect("expected successful parse");
+        let clauses = valid_not_join(parsed, UnifyVars::Implicit);
+
+        // Check each part of the body
+        let mut parts = clauses.into_iter();
+        match (parts.next(), parts.next(), parts.next()) {
+            (Some(clause1), Some(clause2), None) => {
+                assert_eq!(
+                    clause1,
+                    WhereClause::Pattern(Pattern {
+                        source: None,
+                        entity: PatternNonValuePlace::Variable(Variable::from_valid_name("?id")),
+                        attribute: ident("artist", "country"),
+                        value: value_ident("country", "CA"),
+                        tx: PatternNonValuePlace::Placeholder,
+                    }));
+                assert_eq!(
+                    clause2,
+                    WhereClause::Pattern(Pattern {
+                        source: None,
+                        entity: PatternNonValuePlace::Variable(Variable::from_valid_name("?id")),
+                        attribute: ident("artist", "country"),
+                        value: value_ident("country", "GB"),
+                        tx: PatternNonValuePlace::Placeholder,
+                    }));
+            },
+            _ => panic!(),
+        };
+    }
+
+    #[test]
+    fn test_success_not_join() {
+        let query = r#"[:find ?artist
+                        :where [?artist :artist/name]
+                               (not-join [?artist]
+                                   [?release :release/artists ?artist]
+                                   [?release :release/year 1970])]"#;
+        let parsed = parse_find_string(query).expect("expected successful parse");
+        let clauses = valid_not_join(parsed, UnifyVars::Explicit(vec![Variable::from_valid_name("?artist")]));
+
+        // Let's do some detailed parse checks.
+        let mut parts = clauses.into_iter();
+        match (parts.next(), parts.next(), parts.next()) {
+            (Some(clause1), Some(clause2), None) => {
+                assert_eq!(
+                    clause1,
+                    WhereClause::Pattern(Pattern {
+                        source: None,
+                        entity: PatternNonValuePlace::Variable(Variable::from_valid_name("?release")),
+                        attribute: ident("release", "artists"),
+                        value: PatternValuePlace::Variable(Variable::from_valid_name("?artist")),
+                        tx: PatternNonValuePlace::Placeholder,
+                    }));
+                assert_eq!(
+                    clause2,
+                    WhereClause::Pattern(Pattern {
+                        source: None,
+                        entity: PatternNonValuePlace::Variable(Variable::from_valid_name("?release")),
+                        attribute: ident("release", "year"),
+                        value: PatternValuePlace::EntidOrInteger(1970),
+                        tx: PatternNonValuePlace::Placeholder,
+                    }));
+            },
+            _ => panic!(),
+        };
+    }
+    
+    /// Test that a `not-join` that does not use the joining var fails to validate.
+    #[test]
+    fn test_invalid_explicit_not_join_non_matching_join_vars() {
+        let query = r#"[:find ?artist
+                        :where [?artist :artist/name]
+                               (not-join [?artist]
+                                   [?release :release/artists "Pink Floyd"]
+                                   [?release :release/year 1970])]"#;
+        let parsed = parse_find_string(query).expect("expected successful parse");
+        let mut nots = parsed.where_clauses.iter().filter(|&x| match *x {
+            WhereClause::NotJoin(_) => true,
+            _ => false,
+        });
+
+        let clause = nots.next().unwrap().clone();
+        assert_eq!(None, nots.next());
+
+        match clause {
+            WhereClause::NotJoin(not_join) => { let result = validate_not_join(&not_join); 
+                assert!(result.is_err());
+                match result.err().unwrap() {
+                    Error(ErrorKind::NonMatchingVariablesInNotClause, _) => { assert!(true); },
+                    x => panic!("expected NonMatchingVariablesInNotClause error, got {:?}", x),
+                }
+            },
+            _ => panic!(),
+        }
+    }    
 }

query-parser/src/parse.rs

@@ -35,6 +35,7 @@ use self::mentat_parser_utils::value_and_span::{
 };
 
 use self::mentat_query::{
+    Binding,
     Element,
     FindQuery,
     FindSpec,
@@ -42,6 +43,7 @@ use self::mentat_query::{
     FromValue,
     OrJoin,
     OrWhereClause,
+    NotJoin,
     Pattern,
     PatternNonValuePlace,
     PatternValuePlace,
@@ -50,7 +52,9 @@ use self::mentat_query::{
     SrcVar,
     UnifyVars,
     Variable,
+    VariableOrPlaceholder,
     WhereClause,
+    WhereFn,
 };
 
 error_chain! {
@@ -129,11 +133,56 @@ def_parser!(Where, pattern_non_value_place, PatternNonValuePlace, {
     satisfy_map(PatternNonValuePlace::from_value)
 });
 
-def_matches_plain_symbol!(Where, and, "and");
 
-def_matches_plain_symbol!(Where, or, "or");
+def_parser!(Where, and, edn::ValueAndSpan, {
+    satisfy(|v: edn::ValueAndSpan| {
+        if let edn::SpannedValue::PlainSymbol(ref s) = v.inner {
+            s.0.as_str() == "and"
+        } else {
+            false
+        }
+    })
+});
 
-def_matches_plain_symbol!(Where, or_join, "or-join");
+def_parser!(Where, or, edn::ValueAndSpan, {
+    satisfy(|v: edn::ValueAndSpan| {
+        if let edn::SpannedValue::PlainSymbol(ref s) = v.inner {
+            s.0.as_str() == "or"
+        } else {
+            false
+        }
+    })
+});
+
+def_parser!(Where, or_join, edn::ValueAndSpan, {
+    satisfy(|v: edn::ValueAndSpan| {
+        if let edn::SpannedValue::PlainSymbol(ref s) = v.inner {
+            s.0.as_str() == "or-join"
+        } else {
+            false
+        }
+    })
+});
+
+def_parser!(Where, not, edn::ValueAndSpan, {
+    satisfy(|v: edn::ValueAndSpan| {
+        if let edn::SpannedValue::PlainSymbol(ref s) = v.inner {
+            s.0.as_str() == "not"
+        } else {
+            false
+        }
+    })
+});
+
+def_parser!(Where, not_join, edn::ValueAndSpan, {
+    satisfy(|v: edn::ValueAndSpan| {
+        if let edn::SpannedValue::PlainSymbol(ref s) = v.inner {
+            s.0.as_str() == "not-join"
+        } else {
+            false
+        }
+    })
+});
 
 def_parser!(Where, rule_vars, Vec<Variable>, {
     seq()
@@ -182,6 +231,33 @@ def_parser!(Where, or_join_clause, WhereClause, {
             }))
 });
 
+def_parser!(Where, not_clause, WhereClause, {
+    seq()
+        .of_exactly(Where::not()
+            .with(many1(Where::clause()))
+            .map(|clauses| {
+                WhereClause::NotJoin(
+                    NotJoin {
+                        unify_vars: UnifyVars::Implicit,
+                        clauses: clauses,
+                    })
+            }))
+});
+
+def_parser!(Where, not_join_clause, WhereClause, {
+    seq()
+        .of_exactly(Where::not_join()
+            .with(Where::rule_vars())
+            .and(many1(Where::clause()))
+            .map(|(vars, clauses)| {
+                WhereClause::NotJoin(
+                    NotJoin {
+                        unify_vars: UnifyVars::Explicit(vars),
+                        clauses: clauses,
+                    })
+            }))
+});
+
 /// A vector containing just a parenthesized filter expression.
 def_parser!(Where, pred, WhereClause, {
     // Accept either a nested list or a nested vector here:
@@ -198,6 +274,25 @@ def_parser!(Where, pred, WhereClause, {
                 })))
 });
 
+/// A vector containing a parenthesized function expression and a binding.
+def_parser!(Where, where_fn, WhereClause, {
+    // Accept either a nested list or a nested vector here:
+    // `[(foo ?x ?y) binding]` or `[[foo ?x ?y] binding]`
+    vector()
+        .of_exactly(
+            (seq().of_exactly(
+                (Query::predicate_fn(), Query::arguments())),
+             Bind::binding())
+                    .map(|((f, args), binding)| {
+                        WhereClause::WhereFn(
+                            WhereFn {
+                                operator: f.0,
+                                args: args,
+                                binding: binding,
+                            })
+                    }))
+});
+
 def_parser!(Where, pattern, WhereClause, {
     vector()
         .of_exactly(
@@ -246,8 +341,11 @@ def_parser!(Where, clause, WhereClause, {
             // We don't yet handle source vars.
             try(Where::or_join_clause()),
             try(Where::or_clause()),
+            try(Where::not_join_clause()),
+            try(Where::not_clause()),
 
             try(Where::pred()),
+            try(Where::where_fn()),
     ])
 });
 
@@ -262,6 +360,8 @@ def_matches_plain_symbol!(Find, period, ".");
 
 def_matches_plain_symbol!(Find, ellipsis, "...");
 
+def_matches_plain_symbol!(Find, placeholder, "_");
+
 def_parser!(Find, find_scalar, FindSpec, {
     Query::variable()
         .skip(Find::period())
@@ -366,6 +466,47 @@ def_parser!(Find, query, FindQuery, {
         })
 });
 
+pub struct Bind;
+
+def_parser!(Bind, bind_scalar, Binding, {
+    Query::variable()
+        .skip(eof())
+        .map(|var: Variable| -> Binding { Binding::BindScalar(var) })
+});
+
+def_parser!(Bind, variable_or_placeholder, VariableOrPlaceholder, {
+    Query::variable().map(VariableOrPlaceholder::Variable)
+        .or(Find::placeholder().map(|_| VariableOrPlaceholder::Placeholder))
+});
+
+def_parser!(Bind, bind_coll, Binding, {
+    vector()
+        .of_exactly(Query::variable()
+            .skip(Find::ellipsis()))
+            .map(Binding::BindColl)
+});
+
+def_parser!(Bind, bind_rel, Binding, {
+    vector().of_exactly(
+        many1::<Vec<VariableOrPlaceholder>, _>(Bind::variable_or_placeholder())
+            .map(Binding::BindRel))
+});
+
+def_parser!(Bind, bind_tuple, Binding, {
+    many1::<Vec<VariableOrPlaceholder>, _>(Bind::variable_or_placeholder())
+        .skip(eof())
+        .map(Binding::BindTuple)
+});
+
+def_parser!(Bind, binding, Binding, {
+    // Any one of the four binding types 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([try(Bind::bind_scalar()),
+            try(Bind::bind_coll()),
+            try(Bind::bind_tuple()),
+            try(Bind::bind_rel())])
+});
+
 pub fn parse_find_string(string: &str) -> Result<FindQuery> {
     let expr = edn::parse::value(string)?;
     Find::query()
@@ -385,6 +526,7 @@ mod test {
     use self::combine::Parser;
     use self::edn::OrderedFloat;
     use self::mentat_query::{
+        Binding,
         Element,
         FindSpec,
         NonIntegerConstant,
@@ -393,6 +535,7 @@ mod test {
         PatternValuePlace,
         SrcVar,
         Variable,
+        VariableOrPlaceholder,
     };
 
     use super::*;
@@ -548,6 +691,49 @@ mod test {
                               }));
     }
 
+    #[test]
+    fn test_not() {
+        let e = edn::PlainSymbol::new("?e");
+        let a = edn::PlainSymbol::new("?a");
+        let v = edn::PlainSymbol::new("?v");
+
+        assert_edn_parses_to!(Where::not_clause,
+                              "(not [?e ?a ?v])",
+                              WhereClause::NotJoin(
+                              NotJoin {
+                                  unify_vars: UnifyVars::Implicit,
+                                  clauses: vec![
+                                      WhereClause::Pattern(Pattern {
+                                          source: None,
+                                          entity: PatternNonValuePlace::Variable(variable(e)),
+                                          attribute: PatternNonValuePlace::Variable(variable(a)),
+                                          value: PatternValuePlace::Variable(variable(v)),
+                                          tx: PatternNonValuePlace::Placeholder,
+                                      })],
+                              }));
+    }
+
+    #[test]
+    fn test_not_join() {
+        let e = edn::PlainSymbol::new("?e");
+        let a = edn::PlainSymbol::new("?a");
+        let v = edn::PlainSymbol::new("?v");
+        
+        assert_edn_parses_to!(Where::not_join_clause,
+                              "(not-join [?e] [?e ?a ?v])",
+                              WhereClause::NotJoin(
+                              NotJoin {
+                                  unify_vars: UnifyVars::Explicit(vec![variable(e.clone())]),
+                                  clauses: vec![WhereClause::Pattern(Pattern {
+                                          source: None,
+                                          entity: PatternNonValuePlace::Variable(variable(e)),
+                                          attribute: PatternNonValuePlace::Variable(variable(a)),
+                                          value: PatternValuePlace::Variable(variable(v)),
+                                          tx: PatternNonValuePlace::Placeholder,
+                                      })],
+                              }));
+    }
+
     #[test]
     fn test_find_sp_variable() {
         let sym = edn::PlainSymbol::new("?x");
@@ -598,4 +784,86 @@ mod test {
                           FindSpec::FindTuple(vec![Element::Variable(variable(vx)),
                                                    Element::Variable(variable(vy))]));
     }
+
+    #[test]
+    fn test_bind_scalar() {
+        let vx = edn::PlainSymbol::new("?x");
+        assert_edn_parses_to!(|| vector().of_exactly(Bind::binding()),
+                              "[?x]",
+                              Binding::BindScalar(variable(vx)));
+    }
+
+    #[test]
+    fn test_bind_coll() {
+        let vx = edn::PlainSymbol::new("?x");
+        assert_edn_parses_to!(|| vector().of_exactly(Bind::binding()),
+                              "[[?x ...]]",
+                              Binding::BindColl(variable(vx)));
+    }
+
+    #[test]
+    fn test_bind_rel() {
+        let vx = edn::PlainSymbol::new("?x");
+        let vy = edn::PlainSymbol::new("?y");
+        let vw = edn::PlainSymbol::new("?w");
+        assert_edn_parses_to!(|| vector().of_exactly(Bind::binding()),
+                              "[[?x ?y _ ?w]]",
+                              Binding::BindRel(vec![VariableOrPlaceholder::Variable(variable(vx)),
+                                                    VariableOrPlaceholder::Variable(variable(vy)),
+                                                    VariableOrPlaceholder::Placeholder,
+                                                    VariableOrPlaceholder::Variable(variable(vw)),
+                              ]));
+    }
+
+    #[test]
+    fn test_bind_tuple() {
+        let vx = edn::PlainSymbol::new("?x");
+        let vy = edn::PlainSymbol::new("?y");
+        let vw = edn::PlainSymbol::new("?w");
+        assert_edn_parses_to!(|| vector().of_exactly(Bind::binding()),
+                              "[?x ?y _ ?w]",
+                              Binding::BindTuple(vec![VariableOrPlaceholder::Variable(variable(vx)),
+                                                      VariableOrPlaceholder::Variable(variable(vy)),
+                                                      VariableOrPlaceholder::Placeholder,
+                                                      VariableOrPlaceholder::Variable(variable(vw)),
+                              ]));
+    }
+
+    #[test]
+    fn test_where_fn() {
+        assert_edn_parses_to!(Where::where_fn,
+                              "[(f ?x 1) ?y]",
+                              WhereClause::WhereFn(WhereFn {
+                                  operator: edn::PlainSymbol::new("f"),
+                                  args: vec![FnArg::Variable(Variable::from_valid_name("?x")),
+                                             FnArg::EntidOrInteger(1)],
+                                  binding: Binding::BindScalar(Variable::from_valid_name("?y")),
+                              }));
+
+        assert_edn_parses_to!(Where::where_fn,
+                              "[(f ?x) [?y ...]]",
+                              WhereClause::WhereFn(WhereFn {
+                                  operator: edn::PlainSymbol::new("f"),
+                                  args: vec![FnArg::Variable(Variable::from_valid_name("?x"))],
+                                  binding: Binding::BindColl(Variable::from_valid_name("?y")),
+                              }));
+
+        // assert_edn_parses_to!(Where::where_fn,
+        //                       "[(f) [?y _]]",
+        //                       WhereClause::WhereFn(WhereFn {
+        //                           operator: edn::PlainSymbol::new("f"),
+        //                           args: vec![],
+        //                           binding: Binding::BindRel(vec![VariableOrPlaceholder::Variable(Variable::from_valid_name("?y")),
+        //                                                          VariableOrPlaceholder::Placeholder]),
+        //                       }));
+
+        assert_edn_parses_to!(Where::where_fn,
+                              "[(f) _ ?y]",
+                              WhereClause::WhereFn(WhereFn {
+                                  operator: edn::PlainSymbol::new("f"),
+                                  args: vec![],
+                                  binding: Binding::BindTuple(vec![VariableOrPlaceholder::Placeholder,
+                                                                   VariableOrPlaceholder::Variable(Variable::from_valid_name("?y"))]),
+                              }));
+    }
 }

query-projector/src/lib.rs

@@ -210,7 +210,7 @@ fn project_elements<'a, I: IntoIterator<Item = &'a Element>>(
                 let columns = query.cc
                                    .column_bindings
                                    .get(var)
-                                   .expect("Every variable has a binding");
+                                   .expect(format!("Every variable should have a binding, but {} does not", var.as_str()).as_str());
 
                 let qa = columns[0].clone();
                 let name = column_name(var);
@@ -490,4 +490,4 @@ pub fn query_projection(query: &AlgebraicQuery) -> CombinedProjection {
             },
         }
     }
-}
+}

query-sql/src/lib.rs

@@ -20,6 +20,8 @@ use mentat_core::{
 
 use mentat_query_algebrizer::{
     DatomsColumn,
+    FulltextColumn,
+    FulltextQualifiedAlias,
     QualifiedAlias,
     QueryValue,
     SourceAlias,
@@ -44,6 +46,7 @@ use mentat_sql::{
 /// implementation for each storage backend. Passing `TypedValue`s here allows for that.
 pub enum ColumnOrExpression {
     Column(QualifiedAlias),
+    FulltextColumn(FulltextQualifiedAlias),
     Entid(Entid),       // Because it's so common.
     Integer(i32),       // We use these for type codes etc.
     Long(i64),
@@ -55,6 +58,7 @@ impl From<QueryValue> for ColumnOrExpression {
     fn from(v: QueryValue) -> Self {
         match v {
             QueryValue::Column(c) => ColumnOrExpression::Column(c),
+            QueryValue::FulltextColumn(c) => ColumnOrExpression::FulltextColumn(c),
             QueryValue::Entid(e) => ColumnOrExpression::Entid(e),
             QueryValue::PrimitiveLong(v) => ColumnOrExpression::Long(v),
             QueryValue::TypedValue(v) => ColumnOrExpression::Value(v),
@@ -109,6 +113,14 @@ impl Constraint {
             right: right,
         }
     }
+
+    pub fn fulltext_match(left: ColumnOrExpression, right: ColumnOrExpression) -> Constraint {
+        Constraint::Infix {
+            op: Op("MATCH"), // SQLite specific!
+            left: left,
+            right: right,
+        }
+    }
 }
 
 #[allow(dead_code)]
@@ -157,6 +169,11 @@ fn push_column(qb: &mut QueryBuilder, col: &DatomsColumn) {
     qb.push_sql(col.as_str());
 }
 
+// We know that FulltextColumns are safe to serialize.
+fn push_fulltext_column(qb: &mut QueryBuilder, col: &FulltextColumn) {
+    qb.push_sql(col.as_str());
+}
+
 //---------------------------------------------------------
 // Turn that representation into SQL.
 
@@ -199,6 +216,12 @@ impl QueryFragment for ColumnOrExpression {
                 push_column(out, column);
                 Ok(())
             },
+            &FulltextColumn(FulltextQualifiedAlias(ref table, ref column)) => {
+                out.push_identifier(table.as_str())?;
+                out.push_sql(".");
+                push_fulltext_column(out, column);
+                Ok(())
+            },
             &Entid(entid) => {
                 out.push_sql(entid.to_string().as_str());
                 Ok(())
@@ -406,13 +429,20 @@ impl SelectQuery {
 #[cfg(test)]
 mod tests {
     use super::*;
+
+    use std::rc::Rc;
+
     use mentat_query_algebrizer::DatomsTable;
 
-    fn build_constraint(c: Constraint) -> String {
+    fn build_constraint_query(c: Constraint) -> SQLQuery {
         let mut builder = SQLiteQueryBuilder::new();
         c.push_sql(&mut builder)
          .map(|_| builder.finish())
-         .unwrap().sql
+         .expect("to produce a query for the given constraint")
+    }
+
+    fn build_constraint(c: Constraint) -> String {
+        build_constraint_query(c).sql
     }
 
     #[test]
@@ -469,6 +499,25 @@ mod tests {
         assert_eq!("((123 = 456 AND 789 = 246))", build_constraint(c));
     }
 
+    #[test]
+    fn test_matches_constraint() {
+        let c = Constraint::Infix {
+            op: Op("MATCHES"),
+            left: ColumnOrExpression::FulltextColumn(FulltextQualifiedAlias("fulltext01".to_string(), FulltextColumn::Text)),
+            right: ColumnOrExpression::Value(TypedValue::String(Rc::new("needle".to_string()))),
+        };
+        let q = build_constraint_query(c);
+        assert_eq!("`fulltext01`.text MATCHES $v0", q.sql);
+        assert_eq!(vec![("$v0".to_string(), Rc::new("needle".to_string()))], q.args);
+
+        let c = Constraint::Infix {
+            op: Op("="),
+            left: ColumnOrExpression::FulltextColumn(FulltextQualifiedAlias("fulltext01".to_string(), FulltextColumn::Rowid)),
+            right: ColumnOrExpression::Column(QualifiedAlias("datoms02".to_string(), DatomsColumn::Value)),
+        };
+        assert_eq!("`fulltext01`.rowid = `datoms02`.v", build_constraint(c));
+    }
+
     #[test]
     fn test_end_to_end() {
         // [:find ?x :where [?x 65537 ?v] [?x 65536 ?v]]

query-translator/src/translate.rs

@@ -32,6 +32,8 @@ use mentat_query_algebrizer::{
     ConjoiningClauses,
     DatomsColumn,
     DatomsTable,
+    FulltextColumn,
+    FulltextQualifiedAlias,
     QualifiedAlias,
     QueryValue,
     SourceAlias,
@@ -69,6 +71,12 @@ impl ToColumn for QualifiedAlias {
     }
 }
 
+impl ToColumn for FulltextQualifiedAlias {
+    fn to_column(self) -> ColumnOrExpression {
+        ColumnOrExpression::FulltextColumn(self)
+    }
+}
+
 impl ToConstraint for ColumnIntersection {
     fn to_constraint(self) -> Constraint {
         Constraint::And {
@@ -108,6 +116,11 @@ impl ToConstraint for ColumnConstraint {
             Equals(left, QueryValue::Column(right)) =>
                 Constraint::equal(left.to_column(), right.to_column()),
 
+            Equals(left, QueryValue::FulltextColumn(right)) =>
+                // TODO: figure out if this is the correct abstraction.  Can we make it so that
+                // FulltextColumns::Text is not accepted here?
+                Constraint::equal(left.to_column(), right.to_column()),
+
             Equals(qa, QueryValue::PrimitiveLong(value)) => {
                 let tag_column = qa.for_type_tag().to_column();
                 let value_column = qa.to_column();
@@ -148,6 +161,14 @@ impl ToConstraint for ColumnConstraint {
                 }
             },
 
+            Matches(left, right) => {
+                Constraint::Infix {
+                    op: Op("MATCH"),
+                    left: ColumnOrExpression::FulltextColumn(left),
+                    right: right.into(),
+                }
+            },
+
             HasType(table, value_type) => {
                 let column = QualifiedAlias(table, DatomsColumn::ValueTypeTag).to_column();
                 Constraint::equal(column, ColumnOrExpression::Integer(value_type.value_type_tag()))

query-translator/tests/translate.rs

@@ -58,6 +58,13 @@ fn prepopulated_schema() -> Schema {
         value_type: ValueType::String,
         ..Default::default()
     });
+    associate_ident(&mut schema, NamespacedKeyword::new("foo", "fts"), 100);
+    add_attribute(&mut schema, 100, Attribute {
+        value_type: ValueType::String,
+        index: true,
+        fulltext: true,
+        ..Default::default()
+    });
     schema
 }
 
@@ -241,4 +248,14 @@ fn test_numeric_not_equals_known_attribute() {
     let SQLQuery { sql, args } = translate(&schema, input, None);
     assert_eq!(sql, "SELECT `datoms00`.e AS `?x` FROM `datoms` AS `datoms00` WHERE `datoms00`.a = 99 AND `datoms00`.v <> 12 LIMIT 1");
     assert_eq!(args, vec![]);
-}
+}
+
+#[test]
+fn test_fulltext() {
+    let schema = prepopulated_schema();
+
+    let input = r#"[:find ?entity ?value ?tx ?score :where [(fulltext $ :foo/fts "needle") [?entity ?value ?tx ?score]]]"#;
+    let SQLQuery { sql, args } = translate(&schema, input, None);
+    assert_eq!(sql, "SELECT `datoms00`.e AS `?entity`, `datoms00`.v AS `?value`, `datoms00`.tx AS `?tx`, 0.0 AS `?score` FROM `datoms` AS `datoms00` WHERE `datoms00`.a = 99 AND `datoms00`.v = $v0 LIMIT 1");
+    assert_eq!(args, vec![make_arg("$v0", "needle")]);
+}

query/src/lib.rs

@@ -147,7 +147,11 @@ impl FromValue<SrcVar> for SrcVar {
 impl SrcVar {
     pub fn from_symbol(sym: &PlainSymbol) -> Option<SrcVar> {
         if sym.is_src_symbol() {
-            Some(SrcVar::NamedSrc(sym.plain_name().to_string()))
+            if sym.0 == "$" {
+                Some(SrcVar::DefaultSrc)
+            } else {
+                Some(SrcVar::NamedSrc(sym.plain_name().to_string()))
+            }
         } else {
             None
         }
@@ -185,16 +189,34 @@ pub enum FnArg {
 
 impl FromValue<FnArg> for FnArg {
     fn from_value(v: edn::ValueAndSpan) -> Option<FnArg> {
-        // TODO: support SrcVars.
-        Variable::from_value(v.clone()) // TODO: don't clone!
-                 .and_then(|v| Some(FnArg::Variable(v)))
-                 .or_else(|| {
-                          println!("from_value {}", v.inner);
-            match v.inner {
-                edn::SpannedValue::Integer(i) => Some(FnArg::EntidOrInteger(i)),
-                edn::SpannedValue::Float(f) => Some(FnArg::Constant(NonIntegerConstant::Float(f))),
-                _ => unimplemented!(),
-            }})
+        use edn::SpannedValue::*;
+        match v.inner {
+            Integer(x) =>
+                Some(FnArg::EntidOrInteger(x)),
+            PlainSymbol(ref x) if x.is_src_symbol() =>
+                SrcVar::from_symbol(x).map(FnArg::SrcVar),
+            PlainSymbol(ref x) if x.is_var_symbol() =>
+                Variable::from_symbol(x).map(FnArg::Variable),
+            PlainSymbol(_) => None,
+            NamespacedKeyword(ref x) =>
+                Some(FnArg::Ident(x.clone())),
+            Boolean(x) =>
+                Some(FnArg::Constant(NonIntegerConstant::Boolean(x))),
+            Float(x) =>
+                Some(FnArg::Constant(NonIntegerConstant::Float(x))),
+            BigInteger(ref x) =>
+                Some(FnArg::Constant(NonIntegerConstant::BigInteger(x.clone()))),
+            Text(ref x) =>
+                // TODO: intern strings. #398.
+                Some(FnArg::Constant(NonIntegerConstant::Text(Rc::new(x.clone())))),
+            Nil |
+            NamespacedSymbol(_) |
+            Keyword(_) |
+            Vector(_) |
+            List(_) |
+            Set(_) |
+            Map(_) => None,
+        }
     }
 }
 
@@ -455,6 +477,25 @@ impl FindSpec {
     }
 }
 
+// Datomic accepts variable or placeholder.  DataScript accepts recursive bindings.  Mentat sticks
+// to the non-recursive form Datomic accepts, which is much simpler to process.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub enum VariableOrPlaceholder {
+    Placeholder,
+    Variable(Variable),
+}
+
+#[derive(Clone,Debug,Eq,PartialEq)]
+pub enum Binding {
+    BindRel(Vec<VariableOrPlaceholder>),
+
+    BindColl(Variable),
+
+    BindTuple(Vec<VariableOrPlaceholder>),
+
+    BindScalar(Variable),
+}
+
 // Note that the "implicit blank" rule applies.
 // A pattern with a reversed attribute — :foo/_bar — is reversed
 // at the point of parsing. These `Pattern` instances only represent
@@ -510,6 +551,13 @@ pub struct Predicate {
     pub args: Vec<FnArg>,
 }
 
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct WhereFn {
+    pub operator: PlainSymbol,
+    pub args: Vec<FnArg>,
+    pub binding: Binding,
+}
+
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub enum UnifyVars {
     /// `Implicit` means the variables in an `or` or `not` are derived from the enclosed pattern.
@@ -570,14 +618,19 @@ pub struct OrJoin {
     pub clauses: Vec<OrWhereClause>,
 }
 
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct NotJoin {
+    pub unify_vars: UnifyVars,
+    pub clauses: Vec<WhereClause>,
+}
+
 #[allow(dead_code)]
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub enum WhereClause {
-    Not,
-    NotJoin,
+    NotJoin(NotJoin),
     OrJoin(OrJoin),
     Pred(Predicate),
-    WhereFn,
+    WhereFn(WhereFn),
     RuleExpr,
     Pattern(Pattern),
 }
@@ -628,9 +681,8 @@ impl ContainsVariables for WhereClause {
             &OrJoin(ref o)  => o.accumulate_mentioned_variables(acc),
             &Pred(ref p)    => p.accumulate_mentioned_variables(acc),
             &Pattern(ref p) => p.accumulate_mentioned_variables(acc),
-            &Not            => (),
-            &NotJoin        => (),
-            &WhereFn        => (),
+            &NotJoin(ref n) => n.accumulate_mentioned_variables(acc),
+            &WhereFn(_)     => (),
             &RuleExpr       => (),
         }
     }
@@ -654,6 +706,14 @@ impl ContainsVariables for OrJoin {
     }
 }
 
+impl ContainsVariables for NotJoin {
+    fn accumulate_mentioned_variables(&self, acc: &mut BTreeSet<Variable>) {
+        for clause in &self.clauses {
+            clause.accumulate_mentioned_variables(acc);
+        }
+    }
+}
+
 impl ContainsVariables for Predicate {
     fn accumulate_mentioned_variables(&self, acc: &mut BTreeSet<Variable>) {
         for arg in &self.args {