perpare for more compact bit operations in JS (#16728)

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/std/private/jsutils.nim b/lib/std/private/jsutils.nim
new file mode 100644
index 000000000..cc463ac74
--- /dev/null
+++ b/lib/std/private/jsutils.nim
@@ -0,0 +1,12 @@
+when defined(js):
+  type
+    ArrayBuffer* = ref object of JsRoot
+    Float64Array* = ref object of JsRoot
+    Uint32Array* = ref object of JsRoot
+
+  func newArrayBuffer*(n: int): ArrayBuffer {.importjs: "new ArrayBuffer(#)".}
+  func newFloat64Array*(buffer: ArrayBuffer): Float64Array {.importjs: "new Float64Array(#)".}
+  func newUint32Array*(buffer: ArrayBuffer): Uint32Array {.importjs: "new Uint32Array(#)".}
+
+  func `[]`*(arr: Uint32Array, i: int): uint32 {.importjs: "#[#]".}
+  func `[]=`*(arr: Float64Array, i: int, v: float) {.importjs: "#[#] = #".}