The primary feature of this release is a new experimental compiler flag - :parallel-build. If set to true the compiler will leverage multiple threads to compile ClojureScript sources. Users have reported signifant gains for cold development and production builds.

This release also includes a variety of small fixes and changes.

As always feedback welcome!

Enhancements

• New experimental :parallel-build compiler option

Changes

• CLJS-1538: Type hint some cljs.core predicates
• Docstring typos
• CLJS-1463: (js-debugger) should generate nil-returning expression
• CLJS-1516: better error message when calling macros with arity
• CLJS-1514: Remove Alpha designators on -watch and ex-
• clojure.core/require is not thread safe, use locks
• CLJS-1505: Add tests to characterize type and instance? behavior
• CLJS-1491: Check :source-map is boolean when :optimizations :none
• split sm/encode into 2 functions so JSON generation is optional

Fixes

• CLJS-1539: Parallel compilation fails on circular dependencies
• CLJS-1425: self-host: cljs.js/eval cb argument inconsistent with docstring
• CLJS-1425: self-host: cljs.js/eval cb argument inconsistent with docstring
• CLJS-1524: Bad hashing for Cons
• CLJS-1487: Fix handling of timestamp comparison for dependencies in JARs
• CLJS-1498: Fix parallel build logging
• CLJS-1477: Do not attempt to resolve "native" type symbols
• CLJS-1236: constructor needs to munged if used as namespace segment
• CLJS-1330: self-host: .toString on int needs parens
• CLJS-1512: Self-host: arithmetic form meta missing :numeric
• CLJS-1506: doc for referred fn displays alias ns
• CLJS-1504: Self-host: Pseudo-namespace for macro namespace analysis metadata
• CLJS-1483: Minor DCE regression with advanced compilation mode