new hacky extension point for aggregate id

Author: zachmu

sql/planbuilder/aggregates.go

@@ -257,7 +257,10 @@ func (b *Builder) buildAggregation(fromScope, projScope *scope, groupingCols []s
 	return outScope
 }
 
-func isAggregateFunc(name string) bool {
+// IsAggregateFunc is a hacky "extension point" to allow for other dialects to declare additional aggregate functions 
+var IsAggregateFunc = IsMySQLAggregateFuncName
+
+func IsMySQLAggregateFuncName(name string) bool {
 	switch name {
 	case "avg", "bit_and", "bit_or", "bit_xor", "count",
 		"group_concat", "json_arrayagg", "json_objectagg",
@@ -794,7 +797,7 @@ func (b *Builder) analyzeHaving(fromScope, projScope *scope, having *ast.Where)
 			return false, nil
 		case *ast.FuncExpr:
 			name := n.Name.Lowered()
-			if isAggregateFunc(name) {
+			if IsAggregateFunc(name) {
 				// record aggregate
 				// TODO: this should get projScope as well
 				_ = b.buildAggregateFunc(fromScope, name, n)

sql/planbuilder/scalar.go

@@ -153,7 +153,7 @@ func (b *Builder) buildScalar(inScope *scope, e ast.Expr) (ex sql.Expression) {
 			return b.buildNameConst(inScope, v)
 		} else if name == "icu_version" {
 			return expression.NewLiteral(icuVersion, types.MustCreateString(query.Type_VARCHAR, int64(len(icuVersion)), sql.Collation_Default))
-		} else if isAggregateFunc(name) && v.Over == nil {
+		} else if IsAggregateFunc(name) && v.Over == nil {
 			// TODO this assumes aggregate is in the same scope
 			// also need to avoid nested aggregates
 			return b.buildAggregateFunc(inScope, name, v)

sql/planbuilder/show.go

@@ -614,7 +614,7 @@ func (b *Builder) buildAsOfExpr(inScope *scope, time ast.Expr) sql.Expression {
 		return expression.NewLiteral(v.String(), types.LongText)
 	case *ast.FuncExpr:
 		// todo(max): more specific validation for nested ASOF functions
-		if isWindowFunc(v.Name.Lowered()) || isAggregateFunc(v.Name.Lowered()) {
+		if isWindowFunc(v.Name.Lowered()) || IsAggregateFunc(v.Name.Lowered()) {
 			err := sql.ErrInvalidAsOfExpression.New(v)
 			b.handleErr(err)
 		}