From: Enric Lafont <enric@1smart.com>
Date: 2002-11-04T07:08:27+09:00
Subject: Re: Thoughts on Ruby


Albert Wagner wrote:

>Yes, superficially, just looking at a piece of Smalltalk code, without 
>understanding what it means, a lot of people come away with the wrong idea: 
>"Smalltalk syntax is wierd and complicated".  Actually, Smalltalk syntax is 
>absurdly simple:  There are ONLY objects and messages. e.g.
>
>conventional language:
>
>if <boolean expression>
>	codeExecutedIfBooleanIsTrue
>else
>	code ExecutedIfBooleanIsFalse
>end
>
>Smalltalk:
>
><boolean expression>
>	IfTrue: [ codeExecutedIfBooleanIsTrue]
>	IfFalse: [ codeExecutedIfBooleanIsFalse]
>
>This does indeed look strange and complicated until you realize that <boolean 
>expression> is an object, that can be sent the message IfTrue: with a code 
>block as an argument that is evaluated by the boolean object if <boolean 
>expression> evaluates to True.  It is exactly the same syntax as:
>  
>
One of the really NICE things in Ruby is the implicit "object" when 
calling functions, this is what enables Ruby to rewrite the
aBoolean ifTrue: [ true Closure] ifFalse: [false Closure]
to
if aBoolean then: [true Closure] else: [false Closure]

in this case, "if" is an Object method that evaluates the boolean expresion.

And yes, it does not fit with the Ruby sintax, but maybe some sintax 
sugar can correct it.... :-)

>[boolean expression]			# object is code block that answers a boolean
>	whileTrue: [ code here ]		# whileTrue: [] is message sent to code block
>
>and:
>
>1 to: 6 do: [ :integer | code here ]  # object is integer 1
>							# to: 6 do: [ ] is message sent to integer 1
>
>It is this consistency in pure languages that cause problems for people coming 
>from such languages to Ruby.  The corrolary is people coming from simple 
>procedural languages (C) and hybrid languages (C++) who have trouble grasping 
>the almost pureness of Ruby.  Ruby sits midway between canonical pure OOP 
>(Smalltalk) and procedural/hybrid languages.  Whether you enter Ruby from the 
>left or right you are bound to be suprised.
><snip>
>
Yes, but in this cases, the sintax sugar can help a lot, because you 
will need to use in very few cases.

Enric