Method emitProjection

compiler/semantic/sql.go:219–260

(columns []column, grouped bool, seq sem.Seq)

}

func (t *translator) emitProjection(columns []column, grouped bool, seq sem.Seq) (sem.Seq, *staticTable) {
	if len(columns) == 0 {
		return seq, nil
	}
	var outs []sem.RecordElem
	var fields []super.Field
	for _, c := range columns {
		outs = append(outs, &sem.FieldElem{
			Node:  c.astExpr,
			Name:  c.name,
			Value: c.semExpr,
		})
		fields = append(fields, super.NewField(c.name, c.typ))
	}
	var in string
	if grouped {
		in = "g"
	} else {
		in = "in"
	}
	loc := columns[0].astExpr //XXX
	e := &sem.RecordExpr{
		Node: loc,
		Elems: []sem.RecordElem{
			&sem.FieldElem{
				Node:  loc,
				Name:  in,
				Value: sem.NewThis(loc, field.Path{in}),
			},
			&sem.FieldElem{
				Node: loc,
				Name: "out",
				Value: &sem.RecordExpr{
					Node:  loc,
					Elems: outs,
				},
			},
		},
	}
	outType := t.sctx.MustLookupTypeRecord(fields)
	return append(seq, sem.NewValues(loc, e)), &staticTable{typ: outType}
}

func (t *translator) genAggregate(loc ast.Loc, scope *selectScope, seq sem.Seq) sem.Seq {
	var aggCols []sem.Assignment