{"id":517,"date":"2009-12-07T16:35:51","date_gmt":"2009-12-07T21:35:51","guid":{"rendered":"http:\/\/vgable.com\/blog\/?p=517"},"modified":"2009-12-07T16:35:59","modified_gmt":"2009-12-07T21:35:59","slug":"dot-syntax-solution","status":"publish","type":"post","link":"https:\/\/vgable.com\/blog\/2009\/12\/07\/dot-syntax-solution\/","title":{"rendered":"Dot Syntax Solution"},"content":{"rendered":"

Surprisingly, the addition of dot syntax<\/em> to Objective-C 2.0 has been a major source of controversy. I wonder if there’s some kind of Bike Shed effect<\/a> at work here: the problem dot-syntax causes is trivial1<\/sup>; while the clarity it brings to code is minor. So it essentially boils down to aesthetics<\/em>. (For the record, I like the dot, even with it’s current flaws, but I don’t believe it’s worth fighting for).<\/p>\n

The Actual Problem<\/h3>\n

The problem<\/a> is that when you see a.b = c;<\/code> you don’t know if it’s:<\/p>\n

    \n
  1. Assigning<\/strong> the b<\/code> field of a struct<\/code><\/strong> to c<\/code>. This basically compiles down to one move<\/code> instruction.<\/li>\n
  2. Invoking<\/strong> the -setB:<\/code> method on an Objective-C object<\/strong>. By convention -setB:<\/code> should update the b<\/code> property of the object to hold the value c<\/code>, and nothing else. But it might have side effects, or be really slow.<\/li>\n<\/ol>\n

    A Solution<\/h3>\n

    Using a different symbol to access Objective-C properties would remove all ambiguity. Nobody would mistake a@b = c;<\/code> as assigning to a C-struct<\/code>. It’s clearly an Objective-C construct.<\/p>\n

    But personally, I’m not a big fan of the @<\/code> character. It’s ugly; it’s noisy; there’re just too many lines in it. I think U+25B8<\/a> ‘BLACK RIGHT-POINTING SMALL TRIANGLE’ would make a better choice,<\/p>\n

    obj▸property = value;<\/code><\/p><\/blockquote>\n

    And since ‘▸’ can’t be part of a valid C identifier, you can basically preprocess your code with s\/▸\/.\/<\/code>, then compile it with existing tools.<\/p>\n

    Of course, it doesn’t matter what character(s) is picked, so long as it’s clearly different from existing C syntax; and you have a way of replacing it with a .<\/code> before building it.<\/p>\n

    1<\/sup> I’ve heard experienced developers complain that dot-syntax = a steeper learning curve for newbies<\/em><\/a>, and that it can<\/em> be confusing, but I haven’t actually seen one come out and say ‘I spent X hours debugging a problem that I couldn’t see because of it’. The fact is, any situation that dot-syntax would obscure is already pathological<\/em>. In the end I just can’t see dot-syntax mattering much.<\/small><\/p>\n","protected":false},"excerpt":{"rendered":"

    Surprisingly, the addition of dot syntax to Objective-C 2.0 has been a major source of controversy. I wonder if there’s some kind of Bike Shed effect at work here: the problem dot-syntax causes is trivial1; while the clarity it brings to code is minor. So it essentially boils down to aesthetics. (For the record, I […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,12,5,4,8],"tags":[543,263,358,48,134],"class_list":["post-517","post","type-post","status-publish","format-standard","hentry","category-cocoa","category-design","category-objective-c","category-programming","category-usability","tag-dot-syntax","tag-objective-c-20","tag-steal-my-ideas-please","tag-syntax","tag-xcode"],"_links":{"self":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/posts\/517","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/comments?post=517"}],"version-history":[{"count":1,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/posts\/517\/revisions"}],"predecessor-version":[{"id":518,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/posts\/517\/revisions\/518"}],"wp:attachment":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/media?parent=517"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/categories?post=517"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/tags?post=517"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}