feat!: Ord と重複する compare 関数を消す

Int.compare, Int64.compare, Duration.compare, Instant.compare を消す．これらの型は Ord を満たすので，メソッド呼び出し n.compare(m) が常に E0335 になっていた（proposals/remove-compare.md, #468）．min, max と TestClock は Ord.compare を呼ぶ． methods__method_call_errors のスナップショットも撮り直す（CI の失敗）．
Allianaab2m · Oct 28, 2026 · Oct 27, 2026 · Oct 27, 2026 · Oct 28, 2026 · Oct 28, 2026
commit e58ccf67184bf97a1400efb713c027488ed62064
diff --git a/crates/emela-codegen-c/tests/programs/core_numeric.emel b/crates/emela-codegen-c/tests/programs/core_numeric.emel
@@ -1,7 +1,7 @@
 fn main() {
-  assert Int.compare((-2147483647 - 1), 2147483647) == Less
-  assert Int.compare(2, 1) == Greater
-  assert Int.compare(1, 1) == Equal
+  assert Ord.compare((-2147483647 - 1), 2147483647) == Less
+  assert Ord.compare(2, 1) == Greater
+  assert Ord.compare(1, 1) == Equal
   assert Int.min(-2, 3) == -2
   assert Int.max(-2, 3) == 3
   assert Int.abs(-3) == 3

diff --git a/crates/emela-codegen-emb/tests/release_0_24/collections.emel b/crates/emela-codegen-emb/tests/release_0_24/collections.emel
@@ -3,7 +3,7 @@ import Std.Set.{Set}
 
 type Key(value: Int)
 impl Key: Eq { fn eq(self, other) { self.value % 10 == other.value % 10 } }
-impl Key: Ord { fn compare(self, other) { Int.compare(self.value % 10, other.value % 10) } }
+impl Key: Ord { fn compare(self, other) { Ord.compare(self.value % 10, other.value % 10) } }
 
 pub fn collections(n: Int) -> Int {
   old = Map.from_list([(3, n + 3), (1, n + 1), (2, n + 2)])

diff --git a/crates/emela-codegen-emb/tests/release_0_24/helpers.emel b/crates/emela-codegen-emb/tests/release_0_24/helpers.emel
@@ -33,7 +33,7 @@ pub fn list_helpers(n: Int) -> Int {
   (indexes, items) = List.unzip(enumerated)
   assert(indexes == [0, 1, 2])
   assert(items == List.take(values, 3))
-  sorted = List.sort_by([(1, n), (0, n + 1), (1, n + 2)], fn((a, _), (b, _)) { Int.compare(a, b) })
+  sorted = List.sort_by([(1, n), (0, n + 1), (1, n + 2)], fn((a, _), (b, _)) { Ord.compare(a, b) })
   assert(sorted == [(0, n + 1), (1, n), (1, n + 2)])
   assert(List.sort([3, 1, 2, 1]) == [1, 1, 2, 3])
   List.fold(items, from: 0, f: fn(acc, value) { acc + value })
@@ -44,13 +44,13 @@ pub fn ascii(text: String) -> String {
 }
 
 pub fn numeric(n: Int) -> Int {
-  assert(Int.compare(n, n) == Equal)
+  assert(Ord.compare(n, n) == Equal)
   assert(Int.min(n, n) == n)
   assert(Int.max(n, n) == n)
   Int.abs(n)
 }
 pub fn numeric64(n: Int64) -> Int64 {
-  assert(Int64.compare(n, n) == Equal)
+  assert(Ord.compare(n, n) == Equal)
   Int64.abs(Int64.min(n, Int64.max(n, n)))
 }
 pub fn numeric_float(x: Float) -> Bool {

diff --git a/crates/emela-codegen-emb/tests/release_0_24/traits.emel b/crates/emela-codegen-emb/tests/release_0_24/traits.emel
@@ -3,7 +3,7 @@ import Std.Cause.{Cause}
 
 type Key(value: Int)
 impl Key: Eq { fn eq(self, other) { self.value % 10 == other.value % 10 } }
-impl Key: Ord { fn compare(self, other) { Int.compare(self.value % 10, other.value % 10) } }
+impl Key: Ord { fn compare(self, other) { Ord.compare(self.value % 10, other.value % 10) } }
 impl Key: Show { fn show(self) { "K#{self.value}" } }
 
 type Envelope(key: Key, text: String) derive Eq, Ord, Show

diff --git a/crates/emela-core/lib/core/int.emel b/crates/emela-core/lib/core/int.emel
@@ -52,20 +52,9 @@ pub fn shift_right(n: Int, by: Int) -> Int
 @intrinsic
 pub fn shift_right_unsigned(n: Int, by: Int) -> Int
 
-## Returns Less, Equal or Greater without subtracting (which could overflow).
-pub fn compare(a: Int, b: Int) -> Ordering {
-  if a < b {
-    Less
-  } else if a > b {
-    Greater
-  } else {
-    Equal
-  }
-}
-
 ## Returns the larger value, or `a` when equal.
 pub fn max(a: Int, b: Int) -> Int {
-  compare(a, b) match {
+  Ord.compare(a, b) match {
     Less    -> b
     Greater -> a
     Equal   -> a
@@ -74,7 +63,7 @@ pub fn max(a: Int, b: Int) -> Int {
 
 ## Returns the smaller value, or `a` when equal.
 pub fn min(a: Int, b: Int) -> Int {
-  compare(a, b) match {
+  Ord.compare(a, b) match {
     Less    -> a
     Greater -> b
     Equal   -> a

diff --git a/crates/emela-core/lib/core/int64.emel b/crates/emela-core/lib/core/int64.emel
@@ -37,28 +37,17 @@ pub fn shift_right(n: Int64, by: Int) -> Int64
 @intrinsic
 pub fn shift_right_unsigned(n: Int64, by: Int) -> Int64
 
-## Less, Equal or Greater as `a` is less than, equal to or greater than `b`.
-pub fn compare(a: Int64, b: Int64) -> Ordering {
-  if a < b {
-    Less
-  } else if a > b {
-    Greater
-  } else {
-    Equal
-  }
-}
-
 ## The first argument if they are equal.
 pub fn min(a: Int64, b: Int64) -> Int64 {
-  compare(a, b) match {
+  Ord.compare(a, b) match {
     Greater -> b
     _       -> a
   }
 }
 
 ## The first argument if they are equal.
 pub fn max(a: Int64, b: Int64) -> Int64 {
-  compare(a, b) match {
+  Ord.compare(a, b) match {
     Less -> b
     _    -> a
   }

diff --git a/crates/emela-core/lib/std/clock.emel b/crates/emela-core/lib/std/clock.emel
@@ -66,7 +66,7 @@ pub handler TestClock: Clock {
     at = Instant.add(st.get(), Duration.milliseconds(Int64.from_int(if ms < 0 { 0 } else { ms })))
     when_stalled(Instant.to_unix_milliseconds(at))
     st.update(fn(t) {
-      Instant.compare(t, at) match {
+      Ord.compare(t, at) match {
         Less -> at
         _    -> t
       }

diff --git a/crates/emela-core/lib/std/duration.emel b/crates/emela-core/lib/std/duration.emel
@@ -40,16 +40,6 @@ pub fn subtract(d: Duration, other: Duration) -> Duration {
   Duration(milliseconds: d.milliseconds - other.milliseconds)
 }
 
-pub fn compare(d: Duration, other: Duration) -> Ordering {
-  if d.milliseconds < other.milliseconds {
-    Less
-  } else if d.milliseconds > other.milliseconds {
-    Greater
-  } else {
-    Equal
-  }
-}
-
 ## Milliseconds with an `ms` suffix (`1500ms`).
 pub fn to_string(d: Duration) -> String {
   "#{Int64.to_string(d.milliseconds)}ms"

diff --git a/crates/emela-core/lib/std/instant.emel b/crates/emela-core/lib/std/instant.emel
@@ -32,17 +32,6 @@ pub fn since(t: Instant, earlier: Instant) -> Duration {
   Duration.milliseconds(t.milliseconds - earlier.milliseconds)
 }
 
-## Earlier instants are smaller.
-pub fn compare(t: Instant, other: Instant) -> Ordering {
-  if t.milliseconds < other.milliseconds {
-    Less
-  } else if t.milliseconds > other.milliseconds {
-    Greater
-  } else {
-    Equal
-  }
-}
-
 ## UTC in ISO 8601 (`2026-10-12T03:04:05.678Z`). Same format as JS `Date.prototype.toISOString`:
 ## years outside 0 to 9999 are written with a sign and six digits (`+010000`, `-000001`).
 pub fn to_string(t: Instant) -> String {

diff --git a/crates/emela-driver/tests/run.rs b/crates/emela-driver/tests/run.rs
@@ -1101,7 +1101,7 @@ fn lists_strings_and_int64_run_through_core() {
   dbg(String.to_ascii_uppercase("Hello, äb 東 @[`{"))
   big = Int64.from_int(2147483647) * Int64.from_int(4)
   one = Int64.from_int(1)
-  dbg((Int64.compare(big, one), Int64.min(big, one), Int64.max(big, one), Int64.abs(-big)))
+  dbg((big.compare(one), Int64.min(big, one), Int64.max(big, one), Int64.abs(-big)))
 }
 "##,
     );
@@ -1148,14 +1148,14 @@ fn main() {
     c.print_line(Duration.to_string(d))
     c.print_line(Int64.to_string(Duration.to_seconds(Duration.milliseconds(-1500))))
     c.print_line(Duration.to_string(Duration.subtract(Duration.hours(1), Duration.minutes(61))))
-    c.print_line(show(Duration.compare(Duration.seconds(1), Duration.milliseconds(1000))))
+    c.print_line(show(Duration.seconds(1).compare(Duration.milliseconds(1000))))
     c.print_line(if Duration.seconds(1) == Duration.milliseconds(1000) { "eq" } else { "ne" })
     start = Instant.from_unix_milliseconds(1760238245678)
     later = start |> Instant.add(Duration.hours(25))
     c.print_line(Instant.to_string(start))
     c.print_line(Instant.to_string(later))
     c.print_line(Duration.to_string(later |> Instant.since(start)))
-    c.print_line(show(Instant.compare(start, later)))
+    c.print_line(show(start.compare(later)))
     c.print_line(Int64.to_string(Instant.to_unix_milliseconds(Instant.subtract(start, Duration.milliseconds(678)))))
     c.print_line(Instant.to_string(Instant.from_unix_milliseconds(0)))
     c.print_line(Instant.to_string(Instant.from_unix_milliseconds(-1)))

diff --git a/crates/emela-types/tests/snapshots/methods__method_call_errors.snap b/crates/emela-types/tests/snapshots/methods__method_call_errors.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/emela-types/tests/methods.rs
+assertion_line: 149
 expression: "render_bodies(r#\"\ntype User(name: String)\n\nfn rename(u: User, name: String) -> User {\n  User(name:, ..u)\n}\n\nfn too_few(u: User) {\n  u.rename()\n}\n\nfn not_called(u: User) {\n  u.rename\n}\n\nfn misspelled(u: User) {\n  u.renmae(\"a\")\n}\n\nfn tuple(p: (Int, Int)) {\n  p.first()\n}\n\nfn unknown() {\n  fn(x) { x.rename(\"a\") }\n}\n\"#)"
 ---
 rename: fn(User, String) -> User
@@ -17,6 +18,6 @@ unknown: ∀ A. fn() -> fn(A) -> {unknown}
   x: ?1
 `u.rename()` WrongArgCount { callee: Some("rename"), expected: 1, found: 0 }
 `rename` MethodNotCalled { ty: Named(Idx::<TyConData>(3), []), name: "rename", receiver: Some("u") }
-`renmae` NoFieldOrFunction { ty: Named(Idx::<TyConData>(3), []), name: "renmae" }
+`renmae` no field or function `renmae` for type `User`
 `first` type `(Int, Int)` has no fields (`first`)
 `rename` FieldOnUnknownType { field: "rename", call: true }