added rand, patched udf registartion

CHANGELOG.md

@@ -1,3 +1,6 @@
+## Feb 14 2019 - v0.17.1
+ - Added Rand udf, patched udf  mappings
+
 ## Feb 13 2019 - v0.17.0
  - Added $Select UDF 
 

data/udf/README.md

@@ -63,3 +63,4 @@
 -  Base64DecodeText
 -  TrimSpace
 -  Elapsed elapsed time  
+-  Rand

data/udf/register.go

@@ -27,9 +27,11 @@ func Register(aMap data.Map) {
 	aMap.Put("Base64DecodeText", Base64DecodeText)
 	aMap.Put("TrimSpace", TrimSpace)
 	aMap.Put("Elapsed", Elapsed)
-	aMap.Put("Sum", Elapsed)
-	aMap.Put("Count", Elapsed)
-	aMap.Put("AsNumber", Elapsed)
+	aMap.Put("Sum", Sum)
+	aMap.Put("Count", Count)
+	aMap.Put("AsNumber", AsNumber)
 	aMap.Put("Select", Select)
+	aMap.Put("Rand", Rand)
+
 
 }

data/udf/util.go

@@ -5,8 +5,10 @@ import (
 	"fmt"
 	"github.com/viant/toolbox"
 	"github.com/viant/toolbox/data"
+	"math/rand"
 	"net/url"
 	"strings"
+	"time"
 )
 
 //Length returns length of slice or string
@@ -336,3 +338,20 @@ func matchPath(xPath string, state data.Map, handler func(value interface{}) err
 	}
 	return nil
 }
+
+//Rand returns random
+func Rand(params interface{}, state data.Map) (interface{}, error) {
+	source:=rand.NewSource(time.Now().UnixNano())
+	generator := rand.New(source)
+	floatValue := generator.Float64()
+	if params == nil || ! toolbox.IsSlice(params) {
+		return floatValue, nil
+	}
+	parameters := toolbox.AsSlice(params)
+	if len(parameters) != 2 {
+		return floatValue, nil
+	}
+	min := toolbox.AsInt(parameters[0])
+	max := toolbox.AsInt(parameters[1])
+	return min + int(float64(max-min)  * floatValue), nil
+}

data/udf/util_test.go

@@ -2,6 +2,7 @@ package udf
 
 import (
 	"github.com/stretchr/testify/assert"
+	"github.com/viant/toolbox"
 	"github.com/viant/toolbox/data"
 	"testing"
 )
@@ -182,3 +183,21 @@ func TestSelect(t *testing.T) {
 	}
 
 }
+
+
+func TestRand(t *testing.T) {
+	{
+		randValue, err := Rand(nil, nil)
+		assert.Nil(t, err)
+		floatValue, err := toolbox.ToFloat(randValue)
+		assert.Nil(t, err)
+		assert.True(t, toolbox.IsFloat(randValue) && floatValue >=0.0 && floatValue <1.0)
+	}
+	{
+		randValue, err := Rand([]interface{}{2, 15}, nil)
+		assert.Nil(t, err)
+		intValue, err := toolbox.ToInt(randValue)
+		assert.Nil(t, err)
+		assert.True(t, toolbox.IsInt(randValue) && intValue >=2 && intValue <15)
+	}
+}