Added tests and more examples

Author: Pramod-Devireddy

.gitignore

@@ -0,0 +1,3 @@
+*.out
+*.so
+*.a

.travis.yml

@@ -0,0 +1,13 @@
+language: go
+
+go:
+  - 1.2
+  - 1.3
+  - 1.14.x
+  - 1.15.x
+  - "1.16.3"
+
+env:
+  - GOARCH: amd64
+script:
+  - go test -v

README.md

@@ -2,7 +2,13 @@
     <h1 align="center"> Go Mathematical Expression Toolkit</h1>
 </p>
 
-The Go Expression Toolkit (Go-ExprTk) is a wrapper library based on C++ Mathematical Expression Toolkit Library ([ExprTk](http://www.partow.net/programming/exprtk/)). It is a simple to use, easy to integrate and extremely efficient run-time mathematical expression parser and evaluation engine. Go-ExprTk supports numerous forms of functional, logical and vector processing semantics and is very easily extendible.
+[![Go Report Card](https://goreportcard.com/badge/github.com/Pramod-Devireddy/go-exprtk)](https://goreportcard.com/report/github.com/Pramod-Devireddy/go-exprtk)
+
+The Go Expression Toolkit (Go-ExprTk) is a wrapper library based on C++ Mathematical Expression Toolkit Library ([ExprTk](http://www.partow.net/programming/exprtk/)).
+
+It is a simple to use, easy to integrate and extremely efficient run-time mathematical expression parser and evaluation engine.
+
+Go-ExprTk supports numerous forms of functional, logical and vector processing semantics and is very easily extendible.
 
 ## Installation
 
@@ -85,3 +91,6 @@ The Go-ExprTk library has the following capabilities:
 ## ❤️ Credits
 
 This module could not be possible without the [ExprTk](http://www.partow.net/programming/exprtk/) library by [Arash Partow](https://github.com/ArashPartow) and the idea of creating the wrapper module by [Narayana Rao G S](https://twitter.com/narayanraogs)
+
+
+Published under MIT License

examples/example-01.go

@@ -6,7 +6,7 @@ import (
 	"github.com/Pramod-Devireddy/go-exprtk"
 )
 
-func main() {
+func example01() {
 	// Create a new exprtk instance
 	exprtkObj := exprtk.NewExprtk()
 

examples/example-02.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"fmt"
+	"math"
+
+	"github.com/Pramod-Devireddy/go-exprtk"
+)
+
+func example02() {
+	var eqn string
+	eqn = "if (eqn == 'avg') avg(x); "
+	eqn += "else if (eqn == 'max') max(x); "
+	eqn += "else if (eqn == 'min') min(x); "
+	eqn += "else if (eqn == 'sum') sum(x); "
+	eqn += "else 0; "
+
+	var eqnStr string
+	var array []float64 = []float64{1, 2, 3, -4.3, 10, -6.5, 7, 8, -1.3}
+
+	exprtkObj := exprtk.NewExprtk()
+	exprtkObj.SetExpression(eqn)
+	exprtkObj.AddStringVariable("eqn")
+	exprtkObj.AddVectorVariable("x")
+	exprtkObj.CompileExpression()
+	exprtkObj.SetVectorVariableValue("x", array)
+
+	eqnStr = "avg"
+	exprtkObj.SetStringVariableValue("eqn", eqnStr)
+	fmt.Println(math.Round(exprtkObj.GetEvaluatedValue()*100) / 100)
+
+	eqnStr = "max"
+	exprtkObj.SetStringVariableValue("eqn", eqnStr)
+	fmt.Println(exprtkObj.GetEvaluatedValue())
+
+	eqnStr = "min"
+	exprtkObj.SetStringVariableValue("eqn", eqnStr)
+	fmt.Println(exprtkObj.GetEvaluatedValue())
+
+	eqnStr = "sum"
+	exprtkObj.SetStringVariableValue("eqn", eqnStr)
+	fmt.Println(exprtkObj.GetEvaluatedValue())
+
+	eqnStr = "xyz"
+	exprtkObj.SetStringVariableValue("eqn", eqnStr)
+	fmt.Println(exprtkObj.GetEvaluatedValue())
+}

examples/examples.go

@@ -0,0 +1,6 @@
+package main
+
+func main() {
+	example01()
+	example02()
+}

exprtk.go

@@ -65,7 +65,7 @@ func (obj GoExprtk) SetVectorVariableValue(varName string, val []float64) {
 func (obj GoExprtk) CompileExpression() error {
 	value := C.compileExpression(obj.exprtk)
 	if value == 0 {
-		return errors.New("Failed to compile the expression")
+		return errors.New("failed to compile the expression")
 	}
 	return nil
 }

exprtk_test.go

@@ -0,0 +1,112 @@
+package exprtk
+
+import (
+	"fmt"
+	"math"
+	"reflect"
+	"testing"
+)
+
+func TestNewExprtk(t *testing.T) {
+	exprtkObj := NewExprtk()
+
+	if reflect.TypeOf(exprtkObj).String() != "exprtk.GoExprtk" {
+		t.Error("NewExprtk returned incorrect type")
+	}
+}
+
+func TestCompileExpression(t *testing.T) {
+	exprtkObj := NewExprtk()
+
+	exprtkObj.SetExpression("x.1 + y.1")
+
+	exprtkObj.AddDoubleVariable("x.1")
+	exprtkObj.AddDoubleVariable("y.1")
+
+	err := exprtkObj.CompileExpression()
+	if err.Error() != "failed to compile the expression" {
+		t.Error("negative case failed")
+	}
+
+	exprtkObj.SetExpression("x + y")
+
+	exprtkObj.AddDoubleVariable("x")
+	exprtkObj.AddDoubleVariable("y")
+
+	err = exprtkObj.CompileExpression()
+	if err != nil {
+		t.Error("failed to compile the expression")
+	}
+}
+
+func TestDoubleVariables(t *testing.T) {
+	exprtkObj := NewExprtk()
+
+	exprtkObj.SetExpression("(x + 2)*(y-2)")
+
+	exprtkObj.AddDoubleVariable("x")
+	exprtkObj.AddDoubleVariable("y")
+
+	err := exprtkObj.CompileExpression()
+	if err != nil {
+		fmt.Println(err.Error())
+		return
+	}
+
+	exprtkObj.SetDoubleVariableValue("x", 18)
+	exprtkObj.SetDoubleVariableValue("y", 32)
+
+	if exprtkObj.GetEvaluatedValue() != 600 {
+		t.Error("Incorrect Value")
+	}
+
+}
+
+func TestMixedVariables(t *testing.T) {
+	var eqn string
+	eqn = "if (eqn == 'avg') avg(x); "
+	eqn += "else if (eqn == 'max') max(x); "
+	eqn += "else if (eqn == 'min') min(x); "
+	eqn += "else if (eqn == 'sum') sum(x); "
+	eqn += "else 0; "
+
+	var eqnStr string
+	var array []float64 = []float64{1, 2, 3, -4.3, 10, -6.5, 7, 8, -1.3}
+
+	exprtkObj := NewExprtk()
+	exprtkObj.SetExpression(eqn)
+	exprtkObj.AddStringVariable("eqn")
+	exprtkObj.AddVectorVariable("x")
+	exprtkObj.CompileExpression()
+	exprtkObj.SetVectorVariableValue("x", array)
+
+	eqnStr = "avg"
+	exprtkObj.SetStringVariableValue("eqn", eqnStr)
+	if math.Round(exprtkObj.GetEvaluatedValue()*10)/10 != 2.1 {
+		t.Error("Incorrect Value")
+	}
+
+	eqnStr = "max"
+	exprtkObj.SetStringVariableValue("eqn", eqnStr)
+	if exprtkObj.GetEvaluatedValue() != 10 {
+		t.Error("Incorrect Value")
+	}
+
+	eqnStr = "min"
+	exprtkObj.SetStringVariableValue("eqn", eqnStr)
+	if exprtkObj.GetEvaluatedValue() != -6.5 {
+		t.Error("Incorrect Value")
+	}
+
+	eqnStr = "sum"
+	exprtkObj.SetStringVariableValue("eqn", eqnStr)
+	if exprtkObj.GetEvaluatedValue() != 18.9 {
+		t.Error("Incorrect Value")
+	}
+
+	eqnStr = "xyz"
+	exprtkObj.SetStringVariableValue("eqn", eqnStr)
+	if exprtkObj.GetEvaluatedValue() != 0.0 {
+		t.Error("Incorrect Value")
+	}
+}