Nothing surprising there. Let’s replace that 3 with the call that returns 3.
$ cat f2.rb
puts "foo".length?"stuff":"empty"
$ ruby f2.rb
f2.rb:1:in `': undefined method `length?' for "foo":String (NoMethodError)
Did you mean? length
But that parsed as "foo".length? and was looking for a method call because ruby methods can end in ? but couldn’t find the method so returned an error.
Let’s put a space in there so that its the length method again without trying to become length?
And this returned what was expected… but this needed a lot more spaces in a lot more places than the puts 3?"stuff":"empty" that worked in the first call.
I agree! I don’t think 3?”stuff”:”empty” should work at all because I think it’s an insane way to type a ternary :) I’m also very open to admitting that it’s just my own strongly worded opinion.
I think that in most cases, syntactically significant whitespace is a horrible idea - the one exception being that you should have space between operators/identifiers/etc. I don’t care how much, and 4 spaces should have no more special meaning than 1, but I do think that using a space to indicate “this thing is a different thing than the thing before it” is important.
3?"bar":"qux" only has the ternary expression as a valid parsing of ?
foo?"bar":"qux" fails because foo may be a method and foo? is also a valid method identifier.
foo ?"bar":"qux" fails because ?" uses the ? unary operator that makes the next character a string. So ?"bar" becomes the string " followed by what looks to be an identifier.
And so…
? character is a valid part of an identifier (but only at the end of a method name)
?x unary operator to create a String from a character
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In Ruby,
foo?a:bparses differently thanfoo ?a:band the first one isn’t parsed a ternary expression.Consider the following code snippets and execution:
Nothing surprising there. Let’s replace that
3with the call that returns3.But that parsed as
"foo".length?and was looking for a method call because ruby methods can end in?but couldn’t find the method so returned an error.Let’s put a space in there so that its the
lengthmethod again without trying to becomelength?It’s apparently expecting something with the
"stuff". Lets put in more spaces.And this returned what was expected… but this needed a lot more spaces in a lot more places than the
puts 3?"stuff":"empty"that worked in the first call.Personally, I think that if you’d rather write
foo?a:bthanfoo ? a : b, you’re probably insaneBut why would
3?"stuff":"empty"work andfoo?"stuff":"empty"not work?Syntactically significant whitespace is a nightmare to deal with.
I agree! I don’t think
3?”stuff”:”empty”should work at all because I think it’s an insane way to type a ternary :) I’m also very open to admitting that it’s just my own strongly worded opinion.I think that in most cases, syntactically significant whitespace is a horrible idea - the one exception being that you should have space between operators/identifiers/etc. I don’t care how much, and 4 spaces should have no more special meaning than 1, but I do think that using a space to indicate “this thing is a different thing than the thing before it” is important.
Talking with a rubyist:
3?"bar":"qux"only has the ternary expression as a valid parsing of?foo?"bar":"qux"fails becausefoomay be a method andfoo?is also a valid method identifier.foo ?"bar":"qux"fails because?"uses the?unary operator that makes the next character a string. So?"bar"becomes the string"followed by what looks to be an identifier.And so…
?character is a valid part of an identifier (but only at the end of a method name)?xunary operator to create a String from a characterexpr?expr:exprternary operatorAnd so…