Add script to build all examples

.gitignore

@@ -7,3 +7,4 @@
 # Libraries don't need dependency lock
 # Dependencies will be locked in applications that use them
 /shard.lock
+/examples/build/*

scripts/build_examples.rb

@@ -0,0 +1,47 @@
+#!/usr/bin/env ruby
+
+require 'optparse'
+require 'fileutils'
+
+options = {
+  release: true,
+  debug: false,
+  clean: false,
+}
+
+OptionParser.new do |opts|
+  opts.banner = "Usage: build_examples.rb [options]"
+
+  opts.on("--release", "Build in release mode") do
+    options[:release] = true
+  end
+
+  opts.on("--no-release", "Build faster") do
+    options[:release] = false
+  end
+
+  opts.on("--clean", "Remove built examples") do
+    options[:clean] = true
+  end
+end.parse!
+
+unless options[:clean]
+  cmd = "crystal build"
+  flags = []
+  flags << "--release" if options[:release]
+  flags << "--no-debug" unless options[:debug]
+
+  Dir.chdir File.join(__dir__, '..')
+  FileUtils.mkdir_p("examples/build")
+  FileUtils.rm("examples/build/assets")
+  FileUtils.ln_s("../../assets", "examples/build/assets")
+  Dir.glob("examples/*.cr").each do |path|
+    full_cmd = %'#{cmd} #{flags.join(" ")} "#{path}"'
+    puts full_cmd
+    system full_cmd
+    bin_name = File.basename(path, ".cr")
+    FileUtils.mv(bin_name, "examples/build/#{bin_name}")
+  end
+else
+  # TODO
+end