Ranked in these QuestionsQuestion Ranking
Pro Modern syntax
Pro Swift is closer to other platforms
Apple’s modern programming language is easier to understand for non-iOS developers and minimizes time for additional explanations and clarifications. Moreover, Swift can be used as a script language. It is an interesting solution for the iOS community to unify writing of build scripts. At the time being iOS developers are split up in regard to this activity. Some of them write build scripts in Bash, others use Ruby, Python, etc. Swift gives an amazing opportunity to be applied to all iOS programming needs.
More details can be found here https://mlsdev.com/blog/51-7-advantages-of-using-swift-over-objective-c
Pro Works with Apple's Cocoa and Cocoa Touch frameworks
Pro Can be used as a Just-In-Time language
Pro Inherent parallelism
Pro Low memory footprint due to reference counting
Pro Backed by Apple
Pro Performance speed comparable to native C
Pro Swift has some clever tricks up its sleeve
Due to having elements of a functional programming language. Things like 'map' and 'filter' for example.
Pro Uses LLVM compiler and Obj-C runtime allowing C, Objective-C, Objective-C++ and Swift code to run side by side within a single program
Pro Superior type inference
Ocaml type inference is so smart that you never have to repeat yourself and keep code very clean, type errors also are very pleasant
Pro Immutability with escape hatches
reason includes true immutability, but it has escape hatches to let you use mutations in exceptional cases.
The same reasonml code can compile to js (eg. run on browsers or node.js, use any lib in npm), or compile to assembly thru ocaml (unless of course you load js externals), running on any device, with C-comparable (or better) performance.
Pro JSX syntax natively supoorted
reason was created by the creator of react, for developers already using JSX to template web or native UIs this results very familiar
Con Swift is a moving target
They've released 1.2 so far, and 2.0 is coming soon. Every small update brings adjustments to paradigms (such as how to do type casting) that can be a little frustrating to absorb. Objective C was also constantly updating, however, but not at the same rate these days.
Con A standard async syntax is pending
Async syntax is not standard across native/js projects and in both cases a bit awkward for non-ocaml devs. Currently this is reasonml most voted issue in their GitHub repo so hopefully, there's news soon.