BernardK
Programming Ruby 3.2 (5th Edition): B1.0 page 240, short option with/without space
page 240, last paragraph, lines 5-7 : the short option can have a space
… … … … … … … … … … … … … … … … … … … … … There’s one slight bit of weirdness here, which is
that a required argument is separated from a long option by a space but is flush against a
short option, so -xTHING
From the doc and experimentation, the marker can be separated by a space from the short option (it MUST be separated from a long option).
parser.on('-x XXX' … or parser.on('-xXXX' … have the same effect.
require "optparse"
parser = OptionParser.new
parser.on('-x XXX', '--xxx', 'Required argument via short name') do |value|
puts "option -x is '-x XXX'"
end
parser.on('-zZZZ', '--zzz', 'Required argument via short name') do |value|
puts "option -z is '-zZZZ'"
end
parser.parse!
% ruby -w rubyworld/option_doc.rb --help
Usage: option_doc [options]
-x, --xxx XXX Required argument via short name
-z, --zzzZZZ Required argument via short name
% ruby -w rubyworld/option_doc.rb -x x
option -x is '-x XXX'
% ruby -w rubyworld/option_doc.rb -z x
option -z is '-zZZZ'
First Post!
noelrappin
Author of Modern Front-End Development for Rails
Interesting, I must have misinterpreted the documentation. Thanks!
Popular Pragmatic Bookshelf topics
In Chapter 3, the source for index introduces Config on page 31, followed by more code including tests; Config isn’t introduced until pag...
New
Some minor things in the paper edition that says “3 2020” on the title page verso, not mentioned in the book’s errata online:
p. 186 But...
New
Working through the steps (checking that the Info,plist matches exactly), run the demo game and what appears is grey but does not fill th...
New
I ran this command after installing the sample application:
$ cards add do something --owner Brian
And got a file not found error:
Fil...
New
@noelrappin
Running the webpack dev server, I receive the following warning:
ERROR in tsconfig.json
TS18003: No inputs were found in c...
New
This is as much a suggestion as a question, as a note for others.
Locally the SGP30 wasn’t available, so I ordered a SGP40. On page 53, ...
New
Is the book’s epub format available to read on Google Play Books?
New
Hi,
I completed chapter 6 but am getting the following error when running:
thread 'main' panicked at 'Failed to load texture: IoError(O...
New
The allprojects block listed on page 245 produces the following error when syncing gradle:
“org.gradle.api.GradleScriptException: A prob...
New
Hi, I need some help, I’m new to rust and was learning through your book. but I got stuck at the last stage of distribution. Whenever I t...
New
Other popular topics
I know that these benchmarks might not be the exact picture of real-world scenario, but still I expect a Rust web framework performing a ...
New
New
poll
poll
Be sure to check out @Dusty’s article posted here: An Introduction to Alternative Keyboard Layouts It’s one of the best write-...
New
I ended up cancelling my Moonlander order as I think it’s just going to be a bit too bulky for me.
I think the Planck and the Preonic (o...
New
The V Programming Language
Simple language for building maintainable programs
V is already mentioned couple of times in the forum, but I...
New
We’ve talked about his book briefly here but it is quickly becoming obsolete - so he’s decided to create a series of 7 podcasts, the firs...
New
Author Spotlight
Jamis Buck
@jamis
This month, we have the pleasure of spotlighting author Jamis Buck, who has written Mazes for Prog...
New
I am trying to crate a game for the Nintendo switch, I wanted to use Java as I am comfortable with that programming language. Can you use...
New
Fight complexity and reclaim the original spirit of agility by learning to simplify how you develop software. The result: a more humane a...
New
Ok, well here are some thoughts and opinions on some of the ergonomic keyboards I have, I guess like mini review of each that I use enoug...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /java
- /emacs
- /haskell
- /svelte
- /typescript
- /onivim
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /elm
- /flutter
- /vscode
- /ash
- /html
- /opensuse
- /zig
- /centos
- /deepseek
- /php
- /scala
- /react-native
- /lisp
- /sublime-text
- /textmate
- /nixos
- /debian
- /agda
- /django
- /deno
- /kubuntu
- /arch-linux
- /nodejs
- /revery
- /ubuntu
- /spring
- /manjaro
- /lua
- /diversity
- /julia
- /markdown
- /c









