diff options
Diffstat (limited to 'challenge-153/bruce-gray/webassembly/ch-1.wat')
| -rw-r--r-- | challenge-153/bruce-gray/webassembly/ch-1.wat | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/challenge-153/bruce-gray/webassembly/ch-1.wat b/challenge-153/bruce-gray/webassembly/ch-1.wat new file mode 100644 index 0000000000..c3d78ef29d --- /dev/null +++ b/challenge-153/bruce-gray/webassembly/ch-1.wat @@ -0,0 +1,35 @@ +(module + (func $left_factorial (export "left_factorial") (param $n i32) (result i32) + (local $acc_left i32) + (local $acc_fact i32) + (local $count i32) + + ;; If $n < 1, return 1, else return the result of the loop. + (i32.lt_s (get_local $n) (i32.const 1)) + if (result i32) + i32.const 1 + else + (set_local $count (i32.const 0)) ;; $count = 0 + (set_local $acc_left (i32.const 1)) ;; $acc_left = 1 + (set_local $acc_fact (i32.const 1)) ;; $acc_fact = 1 + + (loop $accumulate + (set_local $count (i32.add (get_local $count ) (i32.const 1 ))) ;; $count += 1 + (set_local $acc_fact (i32.mul (get_local $acc_fact ) (get_local $count ))) ;; $acc_fact *= $count + (set_local $acc_left (i32.add (get_local $acc_left ) (get_local $acc_fact ))) ;; $acc_left += $acc_fact + + (br_if $accumulate (i32.lt_s (get_local $count) (get_local $n))) ;; loop if $count < $n + ) + + get_local $acc_left ;; return $acc_left + end + ) +) +;; To test, go to https://webassembly.github.io/wabt/demo/wat2wasm/ , +;; copy the code above to the WAT window (top-left), +;; and the code below to the JS window (bottom-left). +;; Output will be in the JS LOG window (bottom-right). +const wasmInstance = new WebAssembly.Instance(wasmModule, {}); +const { left_factorial } = wasmInstance.exports; +console.log([...Array(10+1).keys()].map(left_factorial).join(', ')); +// Output is: 1, 2, 4, 10, 34, 154, 874, 5914, 46234, 409114, 4037914 |