Add PrintError function to print out the IError values

bootstrap/pkg/core/core.go

@@ -31,7 +31,7 @@ func rep(rt *Runtime, line string) {
 	ast, err := ReadString(line)
 
 	if err != nil {
-		fmt.Println(err)
+		PrintError(rt, err)
 	}
 
 	// Debug data, ugly right ? :))
@@ -43,7 +43,7 @@ func rep(rt *Runtime, line string) {
 
 	result, e := Eval(rt, ast)
 	if e != nil {
-		fmt.Printf("Error: %s\n", err)
+		PrintError(rt, e)
 		return
 	}
 	Print(rt, result)

bootstrap/pkg/core/printer.go

@@ -25,3 +25,7 @@ import (
 func Print(rt *Runtime, ast IPrintable) {
 	fmt.Println(ast.String())
 }
+
+func PrintError(rt *Runtime, err IError) {
+	fmt.Printf("Error: %s\n", err.String())
+}