shithub: mc

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Don't count trailing elements when hashing bitsets.

	These don't logically affect the contents, so we shouldn't
	care what they have.

--- a/lib/std/bitset.myr

+++ b/lib/std/bitset.myr

@@ -156,7 +156,13 @@

 }

 const bshash = {a

-	-> std.slhash(a.bits)

+	var end : size

+

+	end = a.bits.len

+	while end > 0 && a.bits[end - 1] == 0

+		end--

+	;;

+	-> std.slhash(a.bits[:end])

 }

 const ensurelen = {bs, len

--- a/lib/std/test/bitset.myr

+++ b/lib/std/test/bitset.myr

@@ -46,6 +46,15 @@

 			var bs = mkset([0, 63, 64, 65, 73, 127, 128, 129][:])

 			testr.check(ctx, std.bscount(bs) == 8, "wrong element count, expected {}", std.bscount(bs))

 			std.bsfree(bs)

+		}],

+		[.name="hash", .fn={ctx

+			var bs = mkset([][:])

+			testr.check(ctx, std.bshash(bs) == 493832887, "wrong hash, expected {}", std.bshash(bs))

+			std.bsput(bs, 123456)

+			testr.check(ctx, std.bshash(bs) == 746495367, "wrong hash, expected {}", std.bshash(bs))

+			std.bsdel(bs, 123456)

+			testr.check(ctx, std.bshash(bs) == 493832887, "wrong hash, expected {}", std.bshash(bs))

+			std.bsfree(bs)

 		}]

 	][:])

 }