add dates to semantic walker

v5/pkg/walkers/semantics/walk.go

@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"regexp"
 	"strings"
+	"time"
 
 	"github.com/yaacov/tree-search-language/v5/pkg/tsl"
 )
@@ -145,6 +146,13 @@ func runSemantics(n tsl.Node, eval EvalFunc) (bool, error) {
 			if r.Func == tsl.ArrayOp {
 				return handleNumberArrayOp(n, eval)
 			}
+		case tsl.DateOp:
+			if r.Func == tsl.DateOp {
+				return handleDateOp(n, eval)
+			}
+			if r.Func == tsl.ArrayOp {
+				return handleDateArrayOp(n, eval)
+			}
 		case tsl.BooleanOp:
 			if r.Func == tsl.BooleanOp {
 				return handleBooleanOp(n, eval)
@@ -210,6 +218,11 @@ func evalIdentNode(node tsl.Node, eval EvalFunc) (tsl.Node, error) {
 			Func: tsl.BooleanOp,
 			Left: v,
 		}
+	case time.Time:
+		n = tsl.Node{
+			Func: tsl.DateOp,
+			Left: v,
+		}
 	case float32:
 		n = tsl.Node{
 			Func: tsl.NumberOp,
@@ -417,6 +430,31 @@ func handleNumberOp(n tsl.Node, eval EvalFunc) (bool, error) {
 	return false, tsl.UnexpectedLiteralError{Literal: n.Func}
 }
 
+func handleDateOp(n tsl.Node, eval EvalFunc) (bool, error) {
+	l := n.Left.(tsl.Node)
+	r := n.Right.(tsl.Node)
+
+	left := l.Left.(time.Time)
+	right := r.Left.(time.Time)
+
+	switch n.Func {
+	case tsl.EqOp:
+		return left == right, nil
+	case tsl.NotEqOp:
+		return left != right, nil
+	case tsl.LtOp:
+		return right.Before(left), nil
+	case tsl.LteOp:
+		return !right.After(left), nil
+	case tsl.GtOp:
+		return left.Before(right), nil
+	case tsl.GteOp:
+		return !left.After(right), nil
+	}
+
+	return false, tsl.UnexpectedLiteralError{Literal: n.Func}
+}
+
 func handleBooleanOp(n tsl.Node, eval EvalFunc) (bool, error) {
 	l := n.Left.(tsl.Node)
 	r := n.Right.(tsl.Node)
@@ -500,6 +538,40 @@ func handleNumberArrayOp(n tsl.Node, eval EvalFunc) (bool, error) {
 	return false, tsl.UnexpectedLiteralError{Literal: n.Func}
 }
 
+func handleDateArrayOp(n tsl.Node, eval EvalFunc) (bool, error) {
+	l := n.Left.(tsl.Node)
+	r := n.Right.(tsl.Node)
+
+	left := l.Left.(time.Time)
+	right := r.Right.([]tsl.Node)
+
+	switch n.Func {
+	case tsl.BetweenOp:
+		begin := right[0].Left.(time.Time)
+		end := right[1].Left.(time.Time)
+
+		return !left.Before(begin) && left.Before(end), nil
+	case tsl.NotBetweenOp:
+		begin := right[0].Left.(time.Time)
+		end := right[1].Left.(time.Time)
+		return left.Before(begin) || !left.Before(end), nil
+	case tsl.InOp:
+		b := false
+		for _, node := range right {
+			b = b || left == node.Left.(time.Time)
+		}
+		return b, nil
+	case tsl.NotInOp:
+		b := true
+		for _, node := range right {
+			b = b && left != node.Left.(time.Time)
+		}
+		return b, nil
+	}
+
+	return false, tsl.UnexpectedLiteralError{Literal: n.Func}
+}
+
 func handleLogicalOp(n tsl.Node, eval EvalFunc) (bool, error) {
 	l := n.Left.(tsl.Node)
 	r := n.Right.(tsl.Node)

v5/pkg/walkers/semantics/walk_test.go

@@ -17,6 +17,7 @@ package semantics
 
 import (
 	"testing"
+	"time"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/ginkgo/extensions/table"
@@ -32,12 +33,14 @@ func TestWalk(t *testing.T) {
 
 var _ = Describe("Walk", func() {
 	// This is the record that we will use for all the tests:
+	date, _ := time.Parse(time.RFC3339, "2020-01-01T00:00:00Z")
 	record := map[string]interface{}{
 		"title":       "A good book",
 		"author":      "Joe",
 		"spec.pages":  14,
 		"spec.rating": 5,
 		"loaned":      true,
+		"date":        date,
 	}
 
 	// This is the evaluation function that we will use to extract fields from the record:
@@ -75,6 +78,11 @@ var _ = Describe("Walk", func() {
 
 		// Booleans
 		Entry("booleans", "spec.pages < 20 and loaned = true", true),
-		Entry("booleans", "spec.pages < 20 and loaned != true", false),
+		Entry("booleans false", "spec.pages < 20 and loaned != true", false),
+
+		// dates
+		Entry("dates", "date = 2020-01-01T00:00:00Z", true),
+		Entry("dates", "date < 2020-01-02T00:00:00Z", false),
+		Entry("dates", "date between 2019-12-30T00:00:00Z and 2020-01-02T00:00:00Z", true),
 	)
 })