It’s because you’re calling pp x.map and passing a block to pp (which ignores it) As explained in the Programming Ruby book Braces have a high precedence; do has a low precedence So, effectively, braces tie to the function call closest to them (x.map) whereas do binds to the furthest away (pp). That’s a bit … Read more
Ruby cookbook says bracket syntax has higher precedence order than do..end Keep in mind that the bracket syntax has a higher precedence than the do..end syntax. Consider the following two snippets of code: 1.upto 3 do |x| puts x end 1.upto 3 { |x| puts x } # SyntaxError: compile error Second example only works … Read more
Check that PATH contains $HOME/.rbenv/shims and $HOME/.rbenv/bin $ env | grep PATH Also check that you have the following in your ~/.bash_profile if using bash or ~/.zshenv if using zsh export PATH=”$HOME/.rbenv/bin:$PATH” eval “$(rbenv init -)” NOTE: Make sure it’s the last setting in your ~/.bash_profile . I ran into an issue where I installed … Read more
It was deemed a “security” risk. You can get around it by using absolute paths File.expand_path(__FILE__) et al or doing require ‘./filename’ (ironically). or by using require_relative ‘filename’ or adding an “include” directory ruby -I . … or the same, using irb; $irb -I .
Your problem is that each time you run the method you are assigning a new value to the constant. This is not allowed, as it makes the constant non-constant; even though the contents of the string are the same (for the moment, anyhow), the actual string object itself is different each time the method is … Read more
” ” allows you to do string interpolation, e.g.: world_type=”Mars” “Hello #{world_type}”
AWS4-HMAC-SHA256, also known as Signature Version 4, (“V4”) is one of two authentication schemes supported by S3. All regions support V4, but US-Standard¹, and many — but not all — other regions, also support the other, older scheme, Signature Version 2 (“V2”). According to http://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-authenticating-requests.html … new S3 regions deployed after January, 2014 will only … Read more
and is the same as && but with lower precedence. They both use short-circuit evaluation. WARNING: and even has lower precedence than = so you’ll usually want to avoid and. An example when and should be used can be found in the Rails Guide under “Avoiding Double Render Errors”.
I am encountering the exact same problem after updating Xcode to 5.1 and news from Apple aren’t good. From Xcode 5.1 Release Notes: The Apple LLVM compiler in Xcode 5.1 treats unrecognized command-line options as errors. This issue has been seen when building both Python native extensions and Ruby Gems, where some invalid compiler options … Read more
I’m going to heavily quote the Object documentation here, because I think it has some great explanations. I encourage you to read it, and also the documentation for these methods as they’re overridden in other classes, like String. Side note: if you want to try these out for yourself on different objects, use something like … Read more