Bob Nystrom
fe3997f825
Introduce a new public C API function wrenGetSlotType() that returns the underlying representation type (bool, num, foreign, list, null, string, or unknown) of the object stored in a given VM slot. This allows C extensions to inspect slot contents without needing to call individual type-checking functions or handle errors from mismatched accessors. The implementation in wren_vm.c uses the existing IS_* macros to determine the type and returns the corresponding WrenType enum value. A new WrenType enum is added to wren.h with WREN_TYPE_BOOL, WREN_TYPE_NUM, WREN_TYPE_FOREIGN, WREN_TYPE_LIST, WREN_TYPE_NULL, WREN_TYPE_STRING, and WREN_TYPE_UNKNOWN. Test coverage is added in test/api/slots.c with a slotTypes() foreign method that verifies all seven type values, and a ForeignType foreign class is introduced in slots.wren to provide a foreign object for testing WREN_TYPE_FOREIGN. The test harness in main.c is updated to support binding foreign class allocate methods via slotsBindClass().
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.
System.print("Hello, world!")
class Wren {
flyTo(city) {
System.print("Flying to %(city)")
}
}
var adjectives = Fiber.new {
["small", "clean", "fast"].each {|word| Fiber.yield(word) }
}
while (!adjectives.isDone) System.print(adjectives.call())
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Wren is small. The VM implementation is under 4,000 semicolons. 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, let's get started. You can even try it in your browser! Excited? Well, come on and get involved!
