vendor tsgo

tools/tsgo/internal/core/binarysearch.go

@@ -0,0 +1,26 @@
+package core
+
+// BinarySearchUniqueFunc works like [slices.BinarySearchFunc], but avoids extra
+// invocations of the comparison function by assuming that only one element
+// in the slice could match the target. Also, unlike [slices.BinarySearchFunc],
+// the comparison function is passed the current index of the element being
+// compared, instead of the target element.
+func BinarySearchUniqueFunc[S ~[]E, E any](x S, cmp func(int, E) int) (int, bool) {
+	n := len(x)
+	if n == 0 {
+		return 0, false
+	}
+	low, high := 0, n-1
+	for low <= high {
+		middle := low + ((high - low) >> 1)
+		value := cmp(middle, x[middle])
+		if value < 0 {
+			low = middle + 1
+		} else if value > 0 {
+			high = middle - 1
+		} else {
+			return middle, true
+		}
+	}
+	return low, false
+}