Add logic to consume and parse options

script/add-grammar

@@ -0,0 +1,85 @@
+#!/usr/bin/env ruby
+
+require "optparse"
+
+ROOT = File.expand_path("../../", __FILE__)
+
+
+# Break a repository URL into its separate components
+def parse_url(input)
+	hosts = "github\.com|bitbucket\.org|gitlab\.com"
+	
+	# HTTPS/HTTP link pointing to recognised hosts
+	if input =~ /^(?:https?:\/\/)?(?:[^.@]+@)?(?:www\.)?(#{hosts})\/([^\/]+)\/([^\/]+)/i
+		{ host: $1.downcase(), user: $2, repo: $3.sub(/\.git$/, "") }
+	# SSH
+	elsif input =~ /^git@(#{hosts}):([^\/]+)\/([^\/]+)\.git$/i
+		{ host: $1.downcase(), user: $2, repo: $3 }
+	# provider:user/repo
+	elsif input =~ /^(github|bitbucket|gitlab):\/?([^\/]+)\/([^\/]+)\/?$/i
+		{ host: $1.downcase(), user: $2, repo: $3 }
+	# user/repo - Common GitHub shorthand
+	elsif input =~ /^\/?([^\/]+)\/([^\/]+)\/?$/
+		{ host: "github.com", user: $1, repo: $2 }
+	else
+		raise "Unsupported URL: #{input}"
+	end
+end
+
+# Isolate the vendor-name component of a submodule path
+def parse_submodule(name)
+	name =~ /^(?:.*(?:vendor\/)?grammars\/)?([^\/]+)/i
+	path = "vendor/grammars/#{$1}"
+	unless File.exist?("#{ROOT}/" + path)
+		warn "Submodule '#{path}' does not exist. Aborting."
+		exit 1
+	end
+	path
+end
+
+usage = """Usage:
+  #{$0} [--replace grammar] url
+Examples:
+  #{$0} https://github.com/Alhadis/language-roff
+  #{$0} --replace sublime-apl https://github.com/Alhadis/language-apl
+"""
+
+
+$replace = nil
+$verbose = false
+
+OptionParser.new do |opts|
+	opts.banner = usage
+	opts.on("-v", "--verbose", "Print verbose feedback to STDOUT") do
+		$verbose = true
+	end
+	opts.on("-rSUBMODULE", "--replace=SUBMODDULE", "Replace an existing grammar submodule.") do |name|
+		$replace = name
+	end
+end.parse!
+
+
+$url = ARGV[0]
+
+# No URL? Print a usage message and bail.
+unless $url
+	warn usage
+	exit 1;
+end
+
+
+# Ensure the given URL is an HTTPS link
+parts = parse_url $url
+https = "https://#{parts[:host]}/#{parts[:user]}/#{parts[:repo]}"
+path  = "vendor/grammars/#{parts[:repo]}"
+repl  = parse_submodule($replace) if $replace
+
+if $verbose
+	puts "Adding grammar"
+	puts "\tFrom:      #{https}"
+	puts "\tInto:      #{path}"
+	puts "\tReplacing: #{repl}" if repl
+	puts "\nRegistering submodule..."
+end
+
+#`git submodule add #{https} #{path}`