[swift-users] "business applications market" flame

Jens Alfke jens at mooseyard.com
Wed Jan 6 12:55:47 CST 2016

> On Jan 6, 2016, at 10:30 AM, Don Wills <don.wills at portablesoftware.com> wrote:
> 1. The lack a Character type that are the constituent elements of a String
> 2. Missing methods (Java names used):  valueOf, charAt, trim(), length(),

No offense, but it sounds like you haven’t read the justifications in the Swift book or on the web. The short form: Unicode is complicated, necessarily so because human writing is complicated. Even the notion of a “character” is problematic. To quote from objc.io's (prerelease) Advanced Swift book: "But even when encoded using 32-bit code units, what a user might consider 'a single character' — as displayed on the screen — might require multiple code points composed together. Most string manipulation code exhibits a certain level of denial about Unicode’s variable-width nature. This can lead to some unpleasant bugs.”

charAt isn’t available because a String is not just a simple “array of characters” as in older / more simplistic languages. Ditto with length.
valueOf IIRC is for converting to/from integers — there are methods on the integer types for that.
trim is one of those methods that is supplied in the Foundation framework, which hasn’t been ported to a Swift-native version yet so isn’t available outside Apple platforms.

> getBytes(), toUpperCase(), toLowerCase()

getBytes is basically a UTF-8 view.
Upper/lowercase conversions are again part of Foundation.

> 3. The lack of the + operator for appending

You can add this in a couple of lines of code if it’s important to you.

> 4. The lack of a StringBuilder (Java again) class

Apples and oranges. Java needs StringBuilder/StringBuffer because its String is always immutable. In Swift mutability is an aspect of the variable containing the String, so the String class itself contains mutating methods.

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