Add a small example project

README.md

@@ -1,2 +1,32 @@
 # eval
-Simple and easy to use parser and evaluator for mathematical expressions.
+A minimalistic math parser for Go. It implements the [shunting-yard-algorithm](https://brilliant.org/wiki/shunting-yard-algorithm/)
+and allows to parse math from strings.
+
+## Work in progress
+The current implementation requires spaces between each math token and does not support trigionometric functions yet.
+
+## Example
+The library can be used as illustrated below:
+
+```go
+package main
+
+import (
+	"fmt"
+
+	"github.com/jacalz/eval"
+)
+
+func main() {
+	input := "( 6 - 2 * ( 6 / 3 ) ) ^ 3"
+
+	result, err := eval.Evaluate(input)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(result)
+}
+```
+
+A more elaborate example can be found in the `example` folder.

example/main.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+
+	"github.com/jacalz/eval"
+)
+
+func main() {
+	fmt.Print("Enter mathematical expression: ")
+	in := bufio.NewReader(os.Stdin)
+	line, err := in.ReadString('\n')
+	if err != nil {
+		panic(err)
+	}
+
+	result, err := eval.Evaluate(line)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println("The result is:", result)
+}