Issue 33: Finished most aspects of the expression language (#38)

- Most aspects of scans and queries can now be represented using the expression language
- All constructs of the expression language can be used to evaluate items

internal/dynamo-browse/models/queryexpr/values.go

@@ -1,12 +1,22 @@
 package queryexpr
 
 import (
+	"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
+	"github.com/lmika/audax/internal/dynamo-browse/models"
 	"strconv"
 
 	"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
 	"github.com/pkg/errors"
 )
 
+func (a *astLiteralValue) evalToIR(info *models.TableInfo) (irAtom, error) {
+	v, err := a.goValue()
+	if err != nil {
+		return nil, err
+	}
+	return irValue{value: v}, nil
+}
+
 func (a *astLiteralValue) dynamoValue() (types.AttributeValue, error) {
 	if a == nil {
 		return nil, nil
@@ -58,3 +68,19 @@ func (a *astLiteralValue) String() string {
 	}
 	return ""
 }
+
+type irValue struct {
+	value any
+}
+
+func (i irValue) calcQueryForScan(info *models.TableInfo) (expression.ConditionBuilder, error) {
+	return expression.ConditionBuilder{}, NodeCannotBeConvertedToQueryError{}
+}
+
+func (i irValue) goValue() any {
+	return i.value
+}
+
+func (a irValue) calcOperand(info *models.TableInfo) expression.OperandBuilder {
+	return expression.Value(a.goValue())
+}