[patch] refactor for better readability (comments, some functions and README)

Author: bnkamalesh

README.md

@@ -18,7 +18,7 @@ Errors package is a drop-in replacement of the built-in Go errors package with n
 5. Helper functions to generate each error type
 6. Helper function to get error Type, error type as int, check if error type is wrapped anywhere in chain
 
-In case of nested errors, the messages (in case of nesting with this package's error) & errors are also looped through the full chain of errors.
+In case of nested errors, the messages & errors are also looped through the full chain of errors.
 
 ### Prerequisites
 
@@ -88,7 +88,7 @@ If error is nested with multiple errors, it loops through all the levels and ret
 
 Before that, over the years I have tried error with stack trace, annotation, custom error package with error codes etc. Finally, I think this package gives the best of all worlds, for most generic usecases.
 
-A sample was already shown in the user friendly message section, following one would show 1-2 scenarios.
+A sample was already shown in the user friendly message section, following one would show a few more scenarios.
 
 ```golang
 package main
@@ -165,16 +165,16 @@ func main() {
 
 ```
 
-[webgo](https://github.com/bnkamalesh/webgo) was used to illustrate the usage of the function, `errors.HTTPStatusCodeMessage`. It returns the appropriate http status code, user friendly message stored within, and a boolean value. Boolean value is `true` if the returned error is of this package's error type.
+[webgo](https://github.com/bnkamalesh/webgo) was used to illustrate the usage of the function, `errors.HTTPStatusCodeMessage`. It returns the appropriate http status code, user friendly message stored within, and a boolean value. Boolean value is `true` if the returned error of type *Error.
 Since we get the status code and message separately, when using any web framework, you can set values according to the respective framework's native functions. In case of Webgo, it wraps errors in a struct of its own. Otherwise, you could directly respond to the HTTP request by calling `errors.WriteHTTP(error,http.ResponseWriter)`. 
 
 Once the app is running, you can check the response by opening `http://localhost:8080` on your browser. Or on terminal
 ```bash
 $ curl http://localhost:8080
-{"errors":"we lost bar2!. bar2 was deceived by bar1 :(","status":500} // HTTP response
+{"errors":"we lost bar2!. bar2 was deceived by bar1 :(","status":500} // output
 ```
 
-And output of the `fmt.Println(err.Error())`
+And the `fmt.Println(err.Error())` generated output on stdout would be:
 ```bash
 /Users/username/go/src/errorscheck/main.go:28 /Users/username/go/src/errorscheck/main.go:20 sinking bar
 ```

errors.go

@@ -116,10 +116,7 @@ func (e *Error) Unwrap() error {
 // Is implements the Is interface required by Go
 func (e *Error) Is(err error) bool {
 	o, _ := err.(*Error)
-	if o == nil {
-		return false
-	}
-	return o == e
+	return o != nil && o == e
 }
 
 // HTTPStatusCode is a convenience method used to get the appropriate HTTP response status code for the respective error type

helper.go

@@ -12,7 +12,7 @@ func newerr(e error, message string, file string, line int, etype errType) *Erro
 		original: e,
 		message:  message,
 		eType:    etype,
-		// '+' concatenation is much faster than using fmt.Sprintf("%s:%d", file, line)
+		// '+' concatenation is ~100x faster than using fmt.Sprintf("%s:%d", file, line)
 		fileLine: file + ":" + strconv.Itoa(line),
 	}
 }
@@ -29,7 +29,7 @@ func Wrap(err error) *Error {
 	return newerr(err, "", file, line, e.eType)
 }
 
-// WrapWithMsg wrap error with a message
+// WrapWithMsg wrap error with a user friendly message
 func WrapWithMsg(err error, msg string) *Error {
 	_, file, line, _ := runtime.Caller(1)
 	e, _ := err.(*Error)
@@ -51,7 +51,7 @@ func NewWithErrMsgType(e error, message string, etype errType) *Error {
 	return newerr(e, message, file, line, etype)
 }
 
-// Internal helper method for creation internal errors
+// Internal helper method for creating internal errors
 func Internal(message string) *Error {
 	_, file, line, _ := runtime.Caller(1)
 	return newerr(nil, message, file, line, TypeInternal)

helper_test.go

@@ -645,7 +645,7 @@ func TestWriteHTTP(t *testing.T) {
 	}
 }
 
-func TestHasCheck(t *testing.T) {
+func TestHasType(t *testing.T) {
 	type args struct {
 		err error
 		et  errType