SPARQL: refactor AggregateExpression

Avoids code duplication

lib/spargebra/src/algebra.rs

@@ -1114,46 +1114,11 @@ impl<'a> fmt::Display for SparqlGraphRootPattern<'a> {
 /// A set function used in aggregates (c.f. [`GraphPattern::Group`]).
 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
 pub enum AggregateExpression {
-    /// [Count](https://www.w3.org/TR/sparql11-query/#defn_aggCount).
+    /// [Count](https://www.w3.org/TR/sparql11-query/#defn_aggCount) with *.
-    Count {
+    CountSolutions { distinct: bool },
-        expr: Option<Box<Expression>>,
+    FunctionCall {
-        distinct: bool,
+        name: AggregateFunction,
-    },
+        expr: Expression,
-    /// [Sum](https://www.w3.org/TR/sparql11-query/#defn_aggSum).
-    Sum {
-        expr: Box<Expression>,
-        distinct: bool,
-    },
-    /// [Avg](https://www.w3.org/TR/sparql11-query/#defn_aggAvg).
-    Avg {
-        expr: Box<Expression>,
-        distinct: bool,
-    },
-    /// [Min](https://www.w3.org/TR/sparql11-query/#defn_aggMin).
-    Min {
-        expr: Box<Expression>,
-        distinct: bool,
-    },
-    /// [Max](https://www.w3.org/TR/sparql11-query/#defn_aggMax).
-    Max {
-        expr: Box<Expression>,
-        distinct: bool,
-    },
-    /// [GroupConcat](https://www.w3.org/TR/sparql11-query/#defn_aggGroupConcat).
-    GroupConcat {
-        expr: Box<Expression>,
-        distinct: bool,
-        separator: Option<String>,
-    },
-    /// [Sample](https://www.w3.org/TR/sparql11-query/#defn_aggSample).
-    Sample {
-        expr: Box<Expression>,
-        distinct: bool,
-    },
-    /// Custom function.
-    Custom {
-        name: NamedNode,
-        expr: Box<Expression>,
         distinct: bool,
     },
 }
@@ -1162,82 +1127,39 @@ impl AggregateExpression {
     /// Formats using the [SPARQL S-Expression syntax](https://jena.apache.org/documentation/notes/sse.html).
     pub(crate) fn fmt_sse(&self, f: &mut impl fmt::Write) -> fmt::Result {
         match self {
-            Self::Count { expr, distinct } => {
+            Self::CountSolutions { distinct } => {
-                write!(f, "(sum")?;
+                write!(f, "(count")?;
-                if *distinct {
-                    write!(f, " distinct")?;
-                }
-                if let Some(expr) = expr {
-                    write!(f, " ")?;
-                    expr.fmt_sse(f)?;
-                }
-                write!(f, ")")
-            }
-            Self::Sum { expr, distinct } => {
-                write!(f, "(sum ")?;
-                if *distinct {
-                    write!(f, "distinct ")?;
-                }
-                expr.fmt_sse(f)?;
-                write!(f, ")")
-            }
-            Self::Avg { expr, distinct } => {
-                write!(f, "(avg ")?;
                 if *distinct {
                     write!(f, " distinct")?;
                 }
-                expr.fmt_sse(f)?;
                 write!(f, ")")
             }
-            Self::Min { expr, distinct } => {
+            Self::FunctionCall {
-                write!(f, "(min ")?;
+                name:
-                if *distinct {
+                    AggregateFunction::GroupConcat {
-                    write!(f, "distinct ")?;
+                        separator: Some(separator),
-                }
+                    },
-                expr.fmt_sse(f)?;
-                write!(f, ")")
-            }
-            Self::Max { expr, distinct } => {
-                write!(f, "(max ")?;
-                if *distinct {
-                    write!(f, "distinct ")?;
-                }
-                expr.fmt_sse(f)?;
-                write!(f, ")")
-            }
-            Self::Sample { expr, distinct } => {
-                write!(f, "(sample ")?;
-                if *distinct {
-                    write!(f, "distinct ")?;
-                }
-                expr.fmt_sse(f)?;
-                write!(f, ")")
-            }
-            Self::GroupConcat {
                 expr,
                 distinct,
-                separator,
             } => {
                 write!(f, "(group_concat ")?;
                 if *distinct {
                     write!(f, "distinct ")?;
                 }
                 expr.fmt_sse(f)?;
-                if let Some(separator) = separator {
+                write!(f, " {})", LiteralRef::new_simple_literal(separator))
-                    write!(f, " {}", LiteralRef::new_simple_literal(separator))?;
-                }
-                write!(f, ")")
             }
-            Self::Custom {
+            Self::FunctionCall {
                 name,
                 expr,
                 distinct,
             } => {
-                write!(f, "({name}")?;
+                write!(f, "(")?;
+                name.fmt_sse(f)?;
+                write!(f, " ")?;
                 if *distinct {
                     write!(f, "distinct ")?;
                 }
-                write!(f, " ")?;
                 expr.fmt_sse(f)?;
                 write!(f, ")")
             }
@@ -1248,61 +1170,22 @@ impl AggregateExpression {
 impl fmt::Display for AggregateExpression {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            Self::Count { expr, distinct } => {
+            Self::CountSolutions { distinct } => {
                 if *distinct {
-                    if let Some(expr) = expr {
-                        write!(f, "COUNT(DISTINCT {expr})")
-                    } else {
                     write!(f, "COUNT(DISTINCT *)")
-                    }
-                } else if let Some(expr) = expr {
-                    write!(f, "COUNT({expr})")
                 } else {
                     write!(f, "COUNT(*)")
                 }
             }
-            Self::Sum { expr, distinct } => {
+            Self::FunctionCall {
-                if *distinct {
+                name:
-                    write!(f, "SUM(DISTINCT {expr})")
+                    AggregateFunction::GroupConcat {
-                } else {
+                        separator: Some(separator),
-                    write!(f, "SUM({expr})")
+                    },
-                }
-            }
-            Self::Min { expr, distinct } => {
-                if *distinct {
-                    write!(f, "MIN(DISTINCT {expr})")
-                } else {
-                    write!(f, "MIN({expr})")
-                }
-            }
-            Self::Max { expr, distinct } => {
-                if *distinct {
-                    write!(f, "MAX(DISTINCT {expr})")
-                } else {
-                    write!(f, "MAX({expr})")
-                }
-            }
-            Self::Avg { expr, distinct } => {
-                if *distinct {
-                    write!(f, "AVG(DISTINCT {expr})")
-                } else {
-                    write!(f, "AVG({expr})")
-                }
-            }
-            Self::Sample { expr, distinct } => {
-                if *distinct {
-                    write!(f, "SAMPLE(DISTINCT {expr})")
-                } else {
-                    write!(f, "SAMPLE({expr})")
-                }
-            }
-            Self::GroupConcat {
                 expr,
                 distinct,
-                separator,
             } => {
                 if *distinct {
-                    if let Some(separator) = separator {
                     write!(
                         f,
                         "GROUP_CONCAT(DISTINCT {}; SEPARATOR = {})",
@@ -1310,20 +1193,15 @@ impl fmt::Display for AggregateExpression {
                         LiteralRef::new_simple_literal(separator)
                     )
                 } else {
-                        write!(f, "GROUP_CONCAT(DISTINCT {expr})")
-                    }
-                } else if let Some(separator) = separator {
                     write!(
                         f,
                         "GROUP_CONCAT({}; SEPARATOR = {})",
                         expr,
                         LiteralRef::new_simple_literal(separator)
                     )
-                } else {
-                    write!(f, "GROUP_CONCAT({expr})")
                 }
             }
-            Self::Custom {
+            Self::FunctionCall {
                 name,
                 expr,
                 distinct,
@@ -1338,6 +1216,59 @@ impl fmt::Display for AggregateExpression {
     }
 }
 
+/// An aggregate function name.
+#[derive(Eq, PartialEq, Debug, Clone, Hash)]
+pub enum AggregateFunction {
+    /// [Count](https://www.w3.org/TR/sparql11-query/#defn_aggCount) with *.
+    Count,
+    /// [Sum](https://www.w3.org/TR/sparql11-query/#defn_aggSum).
+    Sum,
+    /// [Avg](https://www.w3.org/TR/sparql11-query/#defn_aggAvg).
+    Avg,
+    /// [Min](https://www.w3.org/TR/sparql11-query/#defn_aggMin).
+    Min,
+    /// [Max](https://www.w3.org/TR/sparql11-query/#defn_aggMax).
+    Max,
+    /// [GroupConcat](https://www.w3.org/TR/sparql11-query/#defn_aggGroupConcat).
+    GroupConcat {
+        separator: Option<String>,
+    },
+    /// [Sample](https://www.w3.org/TR/sparql11-query/#defn_aggSample).
+    Sample,
+    Custom(NamedNode),
+}
+
+impl AggregateFunction {
+    /// Formats using the [SPARQL S-Expression syntax](https://jena.apache.org/documentation/notes/sse.html).
+    pub(crate) fn fmt_sse(&self, f: &mut impl fmt::Write) -> fmt::Result {
+        match self {
+            Self::Count => write!(f, "count"),
+            Self::Sum => write!(f, "sum"),
+            Self::Avg => write!(f, "avg"),
+            Self::Min => write!(f, "min"),
+            Self::Max => write!(f, "max"),
+            Self::GroupConcat { .. } => write!(f, "group_concat"),
+            Self::Sample => write!(f, "sample"),
+            Self::Custom(iri) => write!(f, "{iri}"),
+        }
+    }
+}
+
+impl fmt::Display for AggregateFunction {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Count => write!(f, "COUNT"),
+            Self::Sum => write!(f, "SUM"),
+            Self::Avg => write!(f, "AVG"),
+            Self::Min => write!(f, "MIN"),
+            Self::Max => write!(f, "MAX"),
+            Self::GroupConcat { .. } => write!(f, "GROUP_CONCAT"),
+            Self::Sample => write!(f, "SAMPLE"),
+            Self::Custom(iri) => iri.fmt(f),
+        }
+    }
+}
+
 /// An ordering comparator used by [`GraphPattern::OrderBy`].
 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
 pub enum OrderExpression {

lib/spargebra/src/parser.rs

@@ -1918,26 +1918,26 @@ parser! {
         rule NotExistsFunc() -> Expression = i("NOT") _ i("EXISTS") _ p:GroupGraphPattern() { Expression::Not(Box::new(Expression::Exists(Box::new(p)))) }
 
         rule Aggregate() -> AggregateExpression =
-            i("COUNT") _ "(" _ i("DISTINCT") _ "*" _ ")" { AggregateExpression::Count { expr: None, distinct: true } } /
+            i("COUNT") _ "(" _ i("DISTINCT") _ "*" _ ")" { AggregateExpression::CountSolutions { distinct: true } } /
-            i("COUNT") _ "(" _ i("DISTINCT") _ e:Expression() _ ")" { AggregateExpression::Count { expr: Some(Box::new(e)), distinct: true } } /
+            i("COUNT") _ "(" _ i("DISTINCT") _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Count, expr, distinct: true } } /
-            i("COUNT") _ "(" _ "*" _ ")" { AggregateExpression::Count { expr: None, distinct: false } } /
+            i("COUNT") _ "(" _ "*" _ ")" { AggregateExpression::CountSolutions { distinct: false } } /
-            i("COUNT") _ "(" _ e:Expression() _ ")" { AggregateExpression::Count { expr: Some(Box::new(e)), distinct: false } } /
+            i("COUNT") _ "(" _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Count, expr, distinct: false } } /
-            i("SUM") _ "(" _ i("DISTINCT") _ e:Expression() _ ")" { AggregateExpression::Sum { expr: Box::new(e), distinct: true } } /
+            i("SUM") _ "(" _ i("DISTINCT") _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Sum, expr, distinct: true } } /
-            i("SUM") _ "(" _ e:Expression() _ ")" { AggregateExpression::Sum { expr: Box::new(e), distinct: false } } /
+            i("SUM") _ "(" _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Sum, expr, distinct: false } } /
-            i("MIN") _ "(" _ i("DISTINCT") _ e:Expression() _ ")" { AggregateExpression::Min { expr: Box::new(e), distinct: true } } /
+            i("MIN") _ "(" _ i("DISTINCT") _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Min, expr, distinct: true } } /
-            i("MIN") _ "(" _ e:Expression() _ ")" { AggregateExpression::Min { expr: Box::new(e), distinct: false } } /
+            i("MIN") _ "(" _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Min, expr, distinct: false } } /
-            i("MAX") _ "(" _ i("DISTINCT") _ e:Expression() _ ")" { AggregateExpression::Max { expr: Box::new(e), distinct: true } } /
+            i("MAX") _ "(" _ i("DISTINCT") _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Max, expr, distinct: true } } /
-            i("MAX") _ "(" _ e:Expression() _ ")" { AggregateExpression::Max { expr: Box::new(e), distinct: false } } /
+            i("MAX") _ "(" _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Max, expr, distinct: false } } /
-            i("AVG") _ "(" _ i("DISTINCT") _ e:Expression() _ ")" { AggregateExpression::Avg { expr: Box::new(e), distinct: true } } /
+            i("AVG") _ "(" _ i("DISTINCT") _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Avg, expr, distinct: true } } /
-            i("AVG") _ "(" _ e:Expression() _ ")" { AggregateExpression::Avg { expr: Box::new(e), distinct: false } } /
+            i("AVG") _ "(" _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Avg, expr, distinct: false } } /
-            i("SAMPLE") _ "(" _ i("DISTINCT") _ e:Expression() _ ")" { AggregateExpression::Sample { expr: Box::new(e), distinct: true } } /
+            i("SAMPLE") _ "(" _ i("DISTINCT") _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Sample, expr, distinct: true } } /
-            i("SAMPLE") _ "(" _ e:Expression() _ ")" { AggregateExpression::Sample { expr: Box::new(e), distinct: false } } /
+            i("SAMPLE") _ "(" _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Sample, expr, distinct: false } } /
-            i("GROUP_CONCAT") _ "(" _ i("DISTINCT") _ e:Expression() _ ";" _ i("SEPARATOR") _ "=" _ s:String() _ ")" { AggregateExpression::GroupConcat { expr: Box::new(e), distinct: true, separator: Some(s) } } /
+            i("GROUP_CONCAT") _ "(" _ i("DISTINCT") _ expr:Expression() _ ";" _ i("SEPARATOR") _ "=" _ s:String() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::GroupConcat { separator: Some(s) }, expr, distinct: true } } /
-            i("GROUP_CONCAT") _ "(" _ i("DISTINCT") _ e:Expression() _ ")" { AggregateExpression::GroupConcat { expr: Box::new(e), distinct: true, separator: None } } /
+            i("GROUP_CONCAT") _ "(" _ i("DISTINCT") _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::GroupConcat { separator: None }, expr, distinct: true } } /
-            i("GROUP_CONCAT") _ "(" _ e:Expression() _ ";" _ i("SEPARATOR") _ "=" _ s:String() _ ")" { AggregateExpression::GroupConcat { expr: Box::new(e), distinct: true, separator: Some(s) } } /
+            i("GROUP_CONCAT") _ "(" _ expr:Expression() _ ";" _ i("SEPARATOR") _ "=" _ s:String() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::GroupConcat { separator: Some(s) }, expr, distinct: true } } /
-            i("GROUP_CONCAT") _ "(" _ e:Expression() _ ")" { AggregateExpression::GroupConcat { expr: Box::new(e), distinct: false, separator: None } } /
+            i("GROUP_CONCAT") _ "(" _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::GroupConcat { separator: None }, expr, distinct: false } } /
-            name:iri() _ "(" _ i("DISTINCT") _ e:Expression() _ ")" { AggregateExpression::Custom { name, expr: Box::new(e), distinct: true } } /
+            name:iri() _ "(" _ i("DISTINCT") _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Custom(name), expr, distinct: true } } /
-            name:iri() _ "(" _ e:Expression() _ ")" { AggregateExpression::Custom { name, expr: Box::new(e), distinct: false } }
+            name:iri() _ "(" _ expr:Expression() _ ")" { AggregateExpression::FunctionCall { name: AggregateFunction::Custom(name), expr, distinct: false } }
 
         rule iriOrFunction() -> Expression = i: iri() _ a: ArgList()? {
             match a {

lib/sparopt/src/algebra.rs

@@ -3,7 +3,7 @@
 use oxrdf::vocab::xsd;
 use rand::random;
 use spargebra::algebra::{
-    AggregateExpression as AlAggregateExpression, Expression as AlExpression,
+    AggregateExpression as AlAggregateExpression, AggregateFunction, Expression as AlExpression,
     GraphPattern as AlGraphPattern, OrderExpression as AlOrderExpression,
 };
 pub use spargebra::algebra::{Function, PropertyPathExpression};
@@ -1538,46 +1538,12 @@ impl Default for MinusAlgorithm {
 /// A set function used in aggregates (c.f. [`GraphPattern::Group`]).
 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
 pub enum AggregateExpression {
-    /// [Count](https://www.w3.org/TR/sparql11-query/#defn_aggCount).
+    CountSolutions {
-    Count {
-        expr: Option<Box<Expression>>,
         distinct: bool,
     },
-    /// [Sum](https://www.w3.org/TR/sparql11-query/#defn_aggSum).
+    FunctionCall {
-    Sum {
+        name: AggregateFunction,
-        expr: Box<Expression>,
+        expr: Expression,
-        distinct: bool,
-    },
-    /// [Avg](https://www.w3.org/TR/sparql11-query/#defn_aggAvg).
-    Avg {
-        expr: Box<Expression>,
-        distinct: bool,
-    },
-    /// [Min](https://www.w3.org/TR/sparql11-query/#defn_aggMin).
-    Min {
-        expr: Box<Expression>,
-        distinct: bool,
-    },
-    /// [Max](https://www.w3.org/TR/sparql11-query/#defn_aggMax).
-    Max {
-        expr: Box<Expression>,
-        distinct: bool,
-    },
-    /// [GroupConcat](https://www.w3.org/TR/sparql11-query/#defn_aggGroupConcat).
-    GroupConcat {
-        expr: Box<Expression>,
-        distinct: bool,
-        separator: Option<String>,
-    },
-    /// [Sample](https://www.w3.org/TR/sparql11-query/#defn_aggSample).
-    Sample {
-        expr: Box<Expression>,
-        distinct: bool,
-    },
-    /// Custom function.
-    Custom {
-        name: NamedNode,
-        expr: Box<Expression>,
         distinct: bool,
     },
 }
@@ -1588,48 +1554,16 @@ impl AggregateExpression {
         graph_name: Option<&NamedNodePattern>,
     ) -> Self {
         match expression {
-            AlAggregateExpression::Count { expr, distinct } => Self::Count {
+            AlAggregateExpression::CountSolutions { distinct } => Self::CountSolutions {
-                expr: expr
-                    .as_ref()
-                    .map(|e| Box::new(Expression::from_sparql_algebra(e, graph_name))),
-                distinct: *distinct,
-            },
-            AlAggregateExpression::Sum { expr, distinct } => Self::Sum {
-                expr: Box::new(Expression::from_sparql_algebra(expr, graph_name)),
-                distinct: *distinct,
-            },
-            AlAggregateExpression::Avg { expr, distinct } => Self::Avg {
-                expr: Box::new(Expression::from_sparql_algebra(expr, graph_name)),
-                distinct: *distinct,
-            },
-            AlAggregateExpression::Min { expr, distinct } => Self::Min {
-                expr: Box::new(Expression::from_sparql_algebra(expr, graph_name)),
-                distinct: *distinct,
-            },
-            AlAggregateExpression::Max { expr, distinct } => Self::Max {
-                expr: Box::new(Expression::from_sparql_algebra(expr, graph_name)),
                 distinct: *distinct,
             },
-            AlAggregateExpression::GroupConcat {
+            AlAggregateExpression::FunctionCall {
-                expr,
-                distinct,
-                separator,
-            } => Self::GroupConcat {
-                expr: Box::new(Expression::from_sparql_algebra(expr, graph_name)),
-                distinct: *distinct,
-                separator: separator.clone(),
-            },
-            AlAggregateExpression::Sample { expr, distinct } => Self::Sample {
-                expr: Box::new(Expression::from_sparql_algebra(expr, graph_name)),
-                distinct: *distinct,
-            },
-            AlAggregateExpression::Custom {
                 name,
                 expr,
                 distinct,
-            } => Self::Custom {
+            } => Self::FunctionCall {
                 name: name.clone(),
-                expr: Box::new(Expression::from_sparql_algebra(expr, graph_name)),
+                expr: Expression::from_sparql_algebra(expr, graph_name),
                 distinct: *distinct,
             },
         }
@@ -1639,46 +1573,16 @@ impl AggregateExpression {
 impl From<&AggregateExpression> for AlAggregateExpression {
     fn from(expression: &AggregateExpression) -> Self {
         match expression {
-            AggregateExpression::Count { expr, distinct } => Self::Count {
+            AggregateExpression::CountSolutions { distinct } => Self::CountSolutions {
-                expr: expr.as_ref().map(|e| Box::new(e.as_ref().into())),
-                distinct: *distinct,
-            },
-            AggregateExpression::Sum { expr, distinct } => Self::Sum {
-                expr: Box::new(expr.as_ref().into()),
-                distinct: *distinct,
-            },
-            AggregateExpression::Avg { expr, distinct } => Self::Avg {
-                expr: Box::new(expr.as_ref().into()),
-                distinct: *distinct,
-            },
-            AggregateExpression::Min { expr, distinct } => Self::Min {
-                expr: Box::new(expr.as_ref().into()),
-                distinct: *distinct,
-            },
-            AggregateExpression::Max { expr, distinct } => Self::Max {
-                expr: Box::new(expr.as_ref().into()),
-                distinct: *distinct,
-            },
-            AggregateExpression::GroupConcat {
-                expr,
-                distinct,
-                separator,
-            } => Self::GroupConcat {
-                expr: Box::new(expr.as_ref().into()),
-                distinct: *distinct,
-                separator: separator.clone(),
-            },
-            AggregateExpression::Sample { expr, distinct } => Self::Sample {
-                expr: Box::new(expr.as_ref().into()),
                 distinct: *distinct,
             },
-            AggregateExpression::Custom {
+            AggregateExpression::FunctionCall {
                 name,
                 expr,
                 distinct,
-            } => Self::Custom {
+            } => Self::FunctionCall {
                 name: name.clone(),
-                expr: Box::new(expr.as_ref().into()),
+                expr: expr.into(),
                 distinct: *distinct,
             },
         }

lib/sparopt/src/optimizer.rs

@@ -157,11 +157,14 @@ impl Optimizer {
                 inner,
                 variables,
                 aggregates,
-            } => GraphPattern::group(
+            } => {
+                // TODO: min, max and sample don't care about DISTINCT
+                GraphPattern::group(
                     Self::normalize_pattern(*inner, input_types),
                     variables,
                     aggregates,
-            ),
+                )
+            }
             GraphPattern::Service {
                 name,
                 inner,

lib/src/sparql/eval.rs

@@ -18,7 +18,7 @@ use rand::random;
 use regex::{Regex, RegexBuilder};
 use sha1::Sha1;
 use sha2::{Sha256, Sha384, Sha512};
-use spargebra::algebra::{Function, PropertyPathExpression};
+use spargebra::algebra::{AggregateFunction, Function, PropertyPathExpression};
 use spargebra::term::{
     GroundSubject, GroundTerm, GroundTermPattern, GroundTriple, NamedNodePattern, TermPattern,
     TriplePattern,
@@ -974,16 +974,8 @@ impl SimpleEvaluator {
                 let aggregate_input_expressions = aggregates
                     .iter()
                     .map(|(_, expression)| match expression {
-                        AggregateExpression::Count { expr, .. } => expr.as_ref().map(|e| {
+                        AggregateExpression::CountSolutions { .. } => None,
-                            self.expression_evaluator(e, encoded_variables, stat_children)
+                        AggregateExpression::FunctionCall { expr, .. } => {
-                        }),
-                        AggregateExpression::Sum { expr, .. }
-                        | AggregateExpression::Avg { expr, .. }
-                        | AggregateExpression::Min { expr, .. }
-                        | AggregateExpression::Max { expr, .. }
-                        | AggregateExpression::GroupConcat { expr, .. }
-                        | AggregateExpression::Sample { expr, .. }
-                        | AggregateExpression::Custom { expr, .. } => {
                             Some(self.expression_evaluator(expr, encoded_variables, stat_children))
                         }
                     })
@@ -1101,52 +1093,26 @@ impl SimpleEvaluator {
         dataset: &Rc<DatasetView>,
         expression: &AggregateExpression,
     ) -> Box<dyn Fn() -> Box<dyn Accumulator>> {
-        match expression {
+        let mut accumulator: Box<dyn Fn() -> Box<dyn Accumulator>> = match expression {
-            AggregateExpression::Count { distinct, .. } => {
+            AggregateExpression::CountSolutions { .. } => {
-                if *distinct {
-                    Box::new(|| Box::new(DistinctAccumulator::new(CountAccumulator::default())))
-                } else {
                 Box::new(|| Box::<CountAccumulator>::default())
             }
-            }
+            AggregateExpression::FunctionCall { name, .. } => match name {
-            AggregateExpression::Sum { distinct, .. } => {
+                AggregateFunction::Count => Box::new(|| Box::<CountAccumulator>::default()),
-                if *distinct {
+                AggregateFunction::Sum => Box::new(|| Box::<SumAccumulator>::default()),
-                    Box::new(|| Box::new(DistinctAccumulator::new(SumAccumulator::default())))
+                AggregateFunction::Min => {
-                } else {
-                    Box::new(|| Box::<SumAccumulator>::default())
-                }
-            }
-            AggregateExpression::Min { .. } => {
                     let dataset = Rc::clone(dataset);
                     Box::new(move || Box::new(MinAccumulator::new(Rc::clone(&dataset))))
-            } // DISTINCT does not make sense with min
+                }
-            AggregateExpression::Max { .. } => {
+                AggregateFunction::Max => {
                     let dataset = Rc::clone(dataset);
                     Box::new(move || Box::new(MaxAccumulator::new(Rc::clone(&dataset))))
-            } // DISTINCT does not make sense with max
-            AggregateExpression::Avg { distinct, .. } => {
-                if *distinct {
-                    Box::new(|| Box::new(DistinctAccumulator::new(AvgAccumulator::default())))
-                } else {
-                    Box::new(|| Box::<AvgAccumulator>::default())
                 }
-            }
+                AggregateFunction::Avg => Box::new(|| Box::<AvgAccumulator>::default()),
-            AggregateExpression::Sample { .. } => Box::new(|| Box::<SampleAccumulator>::default()), // DISTINCT does not make sense with sample
+                AggregateFunction::Sample => Box::new(|| Box::<SampleAccumulator>::default()),
-            AggregateExpression::GroupConcat {
+                AggregateFunction::GroupConcat { separator } => {
-                distinct,
-                separator,
-                ..
-            } => {
                     let dataset = Rc::clone(dataset);
                     let separator = Rc::from(separator.as_deref().unwrap_or(" "));
-                if *distinct {
-                    Box::new(move || {
-                        Box::new(DistinctAccumulator::new(GroupConcatAccumulator::new(
-                            Rc::clone(&dataset),
-                            Rc::clone(&separator),
-                        )))
-                    })
-                } else {
                     Box::new(move || {
                         Box::new(GroupConcatAccumulator::new(
                             Rc::clone(&dataset),
@@ -1154,9 +1120,17 @@ impl SimpleEvaluator {
                         ))
                     })
                 }
+                AggregateFunction::Custom(_) => Box::new(|| Box::new(FailingAccumulator)),
+            },
+        };
+        if matches!(
+            expression,
+            AggregateExpression::CountSolutions { distinct: true }
+                | AggregateExpression::FunctionCall { distinct: true, .. }
+        ) {
+            accumulator = Box::new(move || Box::new(Deduplicate::new(accumulator())));
         }
-            AggregateExpression::Custom { .. } => Box::new(|| Box::new(FailingAccumulator)),
+        accumulator
-        }
     }
 
     fn expression_evaluator(
@@ -5262,14 +5236,13 @@ trait Accumulator {
     fn state(&self) -> Option<EncodedTerm>;
 }
 
-#[derive(Default, Debug)]
+struct Deduplicate {
-struct DistinctAccumulator<T: Accumulator> {
     seen: HashSet<Option<EncodedTerm>>,
-    inner: T,
+    inner: Box<dyn Accumulator>,
 }
 
-impl<T: Accumulator> DistinctAccumulator<T> {
+impl Deduplicate {
-    fn new(inner: T) -> Self {
+    fn new(inner: Box<dyn Accumulator>) -> Self {
         Self {
             seen: HashSet::default(),
             inner,
@@ -5277,7 +5250,7 @@ impl<T: Accumulator> DistinctAccumulator<T> {
     }
 }
 
-impl<T: Accumulator> Accumulator for DistinctAccumulator<T> {
+impl Accumulator for Deduplicate {
     fn add(&mut self, element: Option<EncodedTerm>) {
         if self.seen.insert(element.clone()) {
             self.inner.add(element)