Bob Nystrom
a83205ef89
Implement `containsKey()` native method on Map that returns a boolean indicating whether the given key exists in the map. Add `validateKey()` helper to reject non-value-type keys (objects, lists, fibers, etc.) with a clear runtime error. Refactor `wrenMapGet()` signature to return success/failure via bool and output the value through an out-parameter, enabling both `containsKey()` and the existing subscript operator to share the same key validation and lookup logic. Update `map_subscript` to return `null` instead of crashing when a key is not found. Add test cases for `containsKey` success/failure, and runtime error tests for invalid key types in subscript getter, setter, and containsKey.
Wren is a small, fast, class-based concurrent scripting language
Think Smalltalk in a Lua-sized package with a dash of Erlang and wrapped up in a familiar, modern syntax.
IO.print("Hello, world!")
class Wren {
flyTo(city) {
IO.print("Flying to ", city)
}
}
var adjectives = new Fiber {
["small", "clean", "fast"].map {|word| Fiber.yield(word) }
}
while (!adjectives.isDone) IO.print(adjectives.call)
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Wren is small. The codebase is about 5,000 lines. You can skim the whole thing in an afternoon. It's small, but not dense. It is readable and lovingly-commented.
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Wren is fast. A fast single-pass compiler to tight bytecode, and a compact object representation help Wren compete with other dynamic languages.
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Wren is class-based. There are lots of scripting languages out there, but many have unusual or non-existent object models. Wren places classes front and center.
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Wren is concurrent. Lightweight fibers are core to the execution model and let you organize your program into an army of communicating coroutines.
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Wren is a scripting language. Wren is intended for embedding in applications. It has no dependencies, a small standard library, and an easy-to-use C API. It compiles cleanly as C99, C++98 or anything later.
If you like the sound of this, give it a try! Even better, you can contribute to Wren itself.
