Bob Nystrom
6abebbe906
Replace the internal `foreignStackStart` pointer with a public `apiStack` field that tracks the base of available C API slots. Extract the static `ensureStack` helper into a non-static `wrenEnsureStack` function declared in the header, enabling `wrenEnsureSlots()` to create a fiber and stack when called outside a foreign method. Update `callForeign` to use `apiStack` and adjust `metaCompile` to write results through the new pointer. Add a `ensureOutsideForeign` test that allocates slots on a fresh VM, verifies slot count grows from 0 to 20, and exercises all 20 slots with double values to confirm the stack is correctly initialized and usable.
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!
