improve readme and demo.go clarity.

README.md

@@ -41,14 +41,14 @@ Afterwards, try extracting subcomponents from a URL.
 
 ## Try the example code
 
-All of the following examples can be found at `examples/demo.go`. To run the demo, use the following command:
+All of the following examples can be found at `examples/demo.go`. To play the demo, run the following command:
 
 ```sh
 # `git clone` and `cd` to the go-fasttld repository folder first
 make demo
 ```
 
-### Domain
+### Hostname
 
 ```go
 // Initialise fasttld extractor
@@ -206,16 +206,17 @@ res, _ := extractor.Extract(fasttld.URLParams{URL: url, ConvertURLToPunyCode: tr
 
 ### Parsing errors
 
-`Extract()` returns an error if the parser detects the URL as invalid.
+If the URL is invalid, the second variable returned by `Extract()`, **error**, will be non-nil. Partially extracted subcomponents can still be retrieved from the first variable returned, ***ExtractResult**.
 
 ```go
 extractor, _ := fasttld.New(fasttld.SuffixListParams{})
 url := "https://example!.com" // invalid characters in hostname
 color.New().Println("The following line should be an error message")
-if _, err := extractor.Extract(fasttld.URLParams{URL: url}); err != nil {
+if res, err := extractor.Extract(fasttld.URLParams{URL: url}); err != nil {
     color.New(color.FgHiRed, color.Bold).Print("Error: ")
     color.New(color.FgHiWhite).Println(err)
 }
+fasttld.PrintRes(url, res) // Partially extracted subcomponents can still be retrieved
 ```
 
 ## Testing

examples/demo.go

@@ -10,14 +10,15 @@ import (
 func main() {
 	var fontStyle = []color.Attribute{color.FgHiWhite, color.Bold}
 
+	// Hostname
 	url := "https://user@a.subdomain.example.ac.uk:5000/a/b?id=42"
 
 	extractor, err := fasttld.New(fasttld.SuffixListParams{})
 	if err != nil {
 		log.Fatal(err)
 	}
 	res, _ := extractor.Extract(fasttld.URLParams{URL: url})
-	color.New(fontStyle...).Println("Domain")
+	color.New(fontStyle...).Println("Hostname")
 	fasttld.PrintRes(url, res)
 
 	// Specify custom public suffix list file
@@ -87,8 +88,9 @@ func main() {
 
 	color.New(fontStyle...).Println("Parsing errors")
 	color.New().Println("The following line should be an error message")
-	if _, err := extractor.Extract(fasttld.URLParams{URL: url}); err != nil {
+	if res, err = extractor.Extract(fasttld.URLParams{URL: url}); err != nil {
 		color.New(color.FgHiRed, color.Bold).Print("Error: ")
 		color.New(color.FgHiWhite).Println(err)
 	}
+	fasttld.PrintRes(url, res) // Partially extracted subcomponents can still be retrieved
 }