From 4267e01de9e8a15353015ea4a2a0ac34d73c4ff4 Mon Sep 17 00:00:00 2001
From: Eyal Posener <posener@gmail.com>
Date: Sat, 23 Mar 2019 16:18:44 +0200
Subject: [PATCH] Add support for url titles

---
 goreadme.go                  | 15 +++++++++--
 internal/markdown/comment.go | 51 +++++++++++++++++++++++-------------
 testdata/pkg1/README.md      |  8 +++++-
 testdata/pkg1/pkg1.go        |  8 +++++-
 4 files changed, 60 insertions(+), 22 deletions(-)

diff --git a/goreadme.go b/goreadme.go
index 5d68b0e..19e261d 100644
--- a/goreadme.go
+++ b/goreadme.go
@@ -33,8 +33,19 @@
 //
 // * Code block is recognized by indentation.
 //
-// * URLs will just automatically converted to links
-// (Added support to local links - prefixed by dot and slash, for example: ./cmd).
+// * Inline code is marked with backticks.
+//
+// * URLs will just automatically converted to links.
+//
+// Additionally, some extra formatting was added.
+//
+// * Local paths will be automatically converted to links, for example: ./goreadme.go.
+//
+// * A url and can have a title, as follows: (goreadme website) https://goreadme.herokuapp.com.
+//
+// * A local path and can have a title, as follows: (goreadme main file) ./goreamde.go.
+//
+// * An image can be added: (image/goreadme icon) ./icon.png
 package goreadme
 
 import (
diff --git a/internal/markdown/comment.go b/internal/markdown/comment.go
index 43f5fb9..7d10e90 100644
--- a/internal/markdown/comment.go
+++ b/internal/markdown/comment.go
@@ -27,6 +27,8 @@ const (
 	// This excludes some rare yet valid urls ending in common punctuation
 	// in order to allow sentences ending in URLs.
 
+	// url title (optional)
+	urlTitle = `(\(([^)]+)\)\W)?`
 	// protocol (required) e.g. http
 	protoPart = `(https?|ftp|file|gopher|mailto|nntp)`
 	// host (required) e.g. www.example.com or [::1]:8080
@@ -40,7 +42,7 @@ const (
 	localRx = `\.\/[^\s]+`
 )
 
-var matchRx = regexp.MustCompile(`(` + urlRx + `)|(` + identRx + `)|(` + localRx + `)`)
+var matchRx = regexp.MustCompile(`(` + urlTitle + `((` + urlRx + `)|(` + localRx + `)))|(` + identRx + `)`)
 
 // pairedParensPrefixLen returns the length of the longest prefix of s containing paired parentheses.
 func pairedParensPrefixLen(s string) int {
@@ -80,7 +82,6 @@ func emphasize(w io.Writer, line string, words map[string]string, nice bool) {
 		// m >= 6 (two parenthesized sub-regexps in matchRx, 1st one is urlRx)
 
 		// write text before match
-		// commentEscape(w, line[0:m[0]], nice)
 		fmt.Fprintf(w, line[0:m[0]])
 		// adjust match if necessary
 		match := line[m[0]:m[1]]
@@ -93,39 +94,53 @@ func emphasize(w io.Writer, line string, words map[string]string, nice bool) {
 
 		// analyze match
 		url := ""
+		title := ""
+		image := false
 		italics := false
 		if words != nil {
 			url, italics = words[match]
 		}
+
+		// If the url ends with a punctuation mark, we will hold it here.
+		after := make([]byte, 0, 1)
+
 		if m[2] >= 0 {
+			// A url
 			// match against first parenthesized sub-regexp; must be match against urlRx
 			if !italics {
 				// no alternative URL in words list, use match instead
 				url = match
+				title = match
+				if m[4] >= 0 {
+					title = line[m[6]:m[7]]
+					url = line[m[8]:m[9]]
+					if strings.HasPrefix(title, "image/") {
+						title = strings.TrimPrefix(title, "image/")
+						image = true
+					}
+				}
 			}
-			italics = false // don't italicize URLs
-		}
-		if m[12] >= 0 {
-			// match against first parenthesized sub-regexp; must be match against urlRx
-			if !italics {
-				// no alternative URL in words list, use match instead
-				url = match
-			}
-			italics = false // don't italicize URLs
-		}
 
-		// If the url ends with a punctuation mark, we will hold it here.
-		after := make([]byte, 0, 1)
-
-		// write match
-		if len(url) > 0 {
+			// Remove punctuation mark from url/title suffix.
 			switch url[len(url)-1] {
 			case '.', ',', ':', ';', '?', '!':
 				after = append(after, url[len(url)-1])
+				if title[len(title)-1] == url[len(url)-1] {
+					title = title[:len(title)-1]
+				}
 				url = url[:len(url)-1]
 			}
+
+			italics = false // don't italicize URLs
+		}
+
+		// write match
+		if image {
+			fmt.Fprint(w, "!")
+		}
+		if len(url) > 0 {
 			fmt.Fprint(w, "[")
-			template.HTMLEscape(w, []byte(url))
+			template.HTMLEscape(w, []byte(title))
 			fmt.Fprint(w, "](")
 		}
 		if italics {
diff --git a/testdata/pkg1/README.md b/testdata/pkg1/README.md
index 6c5008b..71f8260 100644
--- a/testdata/pkg1/README.md
+++ b/testdata/pkg1/README.md
@@ -12,10 +12,12 @@ cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est la
 
 A local link should just start with period and slash: [./internal](./internal), another local is [./internal/file.go](./internal/file.go).
 A web page link should just be written as is: [https://goreadme.herokuapp.com](https://goreadme.herokuapp.com), and with path: [https://goreadme.herokuapp.com/projects](https://goreadme.herokuapp.com/projects).
+A url can also have a [title](http://example.org).
+A local path can also have a [title](./pkg.go).
 
 #### Another Section Header
 
-Inline code can be defined with backquotes: `prinlnt("hello world")`, or with indentation:
+Inline code can be defined with backticks: `prinlnt("hello world")`, or with indentation:
 
 ```go
 func main() {
@@ -29,6 +31,10 @@ You could also use lists:
 1. List item number 2.
 1. List item number 3.
 
+An image:
+
+![gopher](https://golang.org/doc/gopher/frontpage.png)
+
 ## Sub Packages
 
 * [subpkg1](./subpkg1): Package subpkg1 is the first subpackage
diff --git a/testdata/pkg1/pkg1.go b/testdata/pkg1/pkg1.go
index 719fc61..bd2942a 100644
--- a/testdata/pkg1/pkg1.go
+++ b/testdata/pkg1/pkg1.go
@@ -10,10 +10,12 @@
 //
 // A local link should just start with period and slash: ./internal, another local is ./internal/file.go.
 // A web page link should just be written as is: https://goreadme.herokuapp.com, and with path: https://goreadme.herokuapp.com/projects.
+// A url can also have a (title) http://example.org.
+// A local path can also have a (title) ./pkg.go.
 //
 // Another Section Header
 //
-// Inline code can be defined with backquotes: `prinlnt("hello world")`, or with indentation:
+// Inline code can be defined with backticks: `prinlnt("hello world")`, or with indentation:
 //
 // 	func main() {
 //		println("hello world")
@@ -24,6 +26,10 @@
 // 1. List item number 1.
 // 1. List item number 2.
 // 1. List item number 3.
+//
+// An image:
+//
+// (image/gopher) https://golang.org/doc/gopher/frontpage.png
 package pkg1
 
 import "fmt"