Side note: The ruby block is usually optional for a Chef resource. It can later be referred to (in other resources, for example) using log.ĪFAIK, the name attribute is mandatory for every Chef resource type as it's what makes it unique, and allows you to, among other things, call actions on it after it has been declared. You're actually creating a log resource whose name attribute is set to "a debug string". This means that, when you say: log "a debug string" do Specifically about Chef resources, their syntax is usually: resource_type(name) do Just for reference, the syntax for that is: foo(bar) do |baz, qux| In some cases, code blocks can receive parameters, but in Chef the resources' blocks never do.
You could then iterate over an array's elements by calling its eachmethod and supplying a block. Theeachiterator loops through every element in the array, callingyieldfor each one. Let's look at how we might implement the Arrayclass'seachiterator that we used in the previous example.
Iterators: methods that return successive elements from some kind ofĪ = %w( ant bee cat dog elk ) # create an arrayĪ.each # iterate over the contents Names of the arguments to receive these parameters between verticalĬode blocks are used throughout the Ruby library to implement You can provide parameters to the call to yield: "In the block") is executed twice, once for Method as coroutines, which transfer control back and forth between The improved syntax is called fenced code. You might be better off thinking of the block and the The code block syntax of Markdown originally involved the use of indentation of the code like so: if foo bar 'Markdown is awesome.' end. This works on one level, but it isn't really the Think of the association of a block with a method as a kind of We then call it, putting a block on the same line, after theĬall (and after any arguments to the method). The following example shows this in action. That method can then invoke the block one or more times using Once you've created a block, you can associate it with a call to a Than C's function pointers), and to implement iterators.Ĭode blocks are just chunks of code between braces or do.end. Implement callbacks (but they're simpler than Java's anonymous innerĬlasses), to pass around chunks of code (but they're more flexible We're about to look at code blocks: chunks of code that you canĪssociate with method invocations, almost as if they were parameters. This section briefly describes one of Ruby's particular strengths. Reflection, ObjectSpace, and Distributed Ruby.But stick with it, because the payoff is big. But stick with it Even if you’ve programmed in other languages, you’ve probably never seen anything like blocks. A code block is denoted through the use of backticks, with a single backtick on each side being. Blocks are a way of encapsulating or packaging statements up and using them wherever you need them. Code blocks change the background of the affected text but leave the overall formatting of the text alone by default. Regular Expressions in Boolean Expressions In Discord, you can separate text and make it really stand out with the use of code blocks.Backslash Sequences in the Substitution.Programming Ruby The Pragmatic Programmer's Guide.