Add benchmark and regression test for #1521. (#1619)

The new style formats this about 200x faster than the old one. It's still kind of slow, but tolerable.

Fix #1521.

Author: munificent

benchmark/case/curry_2.expect

@@ -0,0 +1,39 @@
+typedef Map1<T1, R> = R Function(T1 arg1);
+
+typedef Map8<T1, T2, T3, T4, T5, T6, T7, T8, R> =
+    R Function(
+      T1 arg1,
+      T2 arg2,
+      T3 arg3,
+      T4 arg4,
+      T5 arg5,
+      T6 arg6,
+      T7 arg7,
+      T8 arg8,
+    );
+
+extension Curry8<T1, T2, T3, T4, T5, T6, T7, T8, R>
+    on Map8<T1, T2, T3, T4, T5, T6, T7, T8, R> {
+  Map1<
+    T1,
+    Map1<T2, Map1<T3, Map1<T4, Map1<T5, Map1<T6, Map1<T7, Map1<T8, R>>>>>>>
+  >
+  get curry =>
+      (T1 arg1) =>
+          (T2 arg2) =>
+              (T3 arg3) =>
+                  (T4 arg4) =>
+                      (T5 arg5) =>
+                          (T6 arg6) =>
+                              (T7 arg7) =>
+                                  (T8 arg8) => this(
+                                    arg1,
+                                    arg2,
+                                    arg3,
+                                    arg4,
+                                    arg5,
+                                    arg6,
+                                    arg7,
+                                    arg8,
+                                  );
+}

benchmark/case/curry_2.expect_short

@@ -0,0 +1,15 @@
+typedef Map1<T1, R> = R Function(T1 arg1);
+
+typedef Map8<T1, T2, T3, T4, T5, T6, T7, T8, R> = R Function(
+    T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8);
+
+extension Curry8<T1, T2, T3, T4, T5, T6, T7, T8, R>
+    on Map8<T1, T2, T3, T4, T5, T6, T7, T8, R> {
+  Map1<
+          T1,
+          Map1<T2,
+              Map1<T3, Map1<T4, Map1<T5, Map1<T6, Map1<T7, Map1<T8, R>>>>>>>>
+      get curry => (T1 arg1) => (T2 arg2) => (T3 arg3) => (T4 arg4) =>
+          (T5 arg5) => (T6 arg6) => (T7 arg7) =>
+              (T8 arg8) => this(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
+}

benchmark/case/curry_2.unit

@@ -0,0 +1,15 @@
+typedef Map1<T1, R> = R Function(T1 arg1);
+
+typedef Map8<T1, T2, T3, T4, T5, T6, T7, T8, R> = R Function(
+    T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8);
+
+extension Curry8<T1, T2, T3, T4, T5, T6, T7, T8, R>
+    on Map8<T1, T2, T3, T4, T5, T6, T7, T8, R> {
+  Map1<
+          T1,
+          Map1<T2,
+              Map1<T3, Map1<T4, Map1<T5, Map1<T6, Map1<T7, Map1<T8, R>>>>>>>>
+      get curry => (T1 arg1) => (T2 arg2) => (T3 arg3) => (T4 arg4) =>
+          (T5 arg5) => (T6 arg6) => (T7 arg7) =>
+              (T8 arg8) => this(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
+}

test/tall/regression/1500/1521.unit

@@ -0,0 +1,56 @@
+>>>
+typedef Map1<T1, R> = R Function(T1 arg1);
+
+typedef Map8<T1, T2, T3, T4, T5, T6, T7, T8, R> = R Function(
+    T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8);
+
+extension Curry8<T1, T2, T3, T4, T5, T6, T7, T8, R>
+    on Map8<T1, T2, T3, T4, T5, T6, T7, T8, R> {
+  Map1<
+          T1,
+          Map1<T2,
+              Map1<T3, Map1<T4, Map1<T5, Map1<T6, Map1<T7, Map1<T8, R>>>>>>>>
+      get curry => (T1 arg1) => (T2 arg2) => (T3 arg3) => (T4 arg4) =>
+          (T5 arg5) => (T6 arg6) => (T7 arg7) =>
+              (T8 arg8) => this(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
+}
+<<<
+typedef Map1<T1, R> = R Function(T1 arg1);
+
+typedef Map8<T1, T2, T3, T4, T5, T6, T7, T8, R> =
+    R Function(
+      T1 arg1,
+      T2 arg2,
+      T3 arg3,
+      T4 arg4,
+      T5 arg5,
+      T6 arg6,
+      T7 arg7,
+      T8 arg8,
+    );
+
+extension Curry8<T1, T2, T3, T4, T5, T6, T7, T8, R>
+    on Map8<T1, T2, T3, T4, T5, T6, T7, T8, R> {
+  Map1<
+    T1,
+    Map1<T2, Map1<T3, Map1<T4, Map1<T5, Map1<T6, Map1<T7, Map1<T8, R>>>>>>>
+  >
+  get curry =>
+      (T1 arg1) =>
+          (T2 arg2) =>
+              (T3 arg3) =>
+                  (T4 arg4) =>
+                      (T5 arg5) =>
+                          (T6 arg6) =>
+                              (T7 arg7) =>
+                                  (T8 arg8) => this(
+                                    arg1,
+                                    arg2,
+                                    arg3,
+                                    arg4,
+                                    arg5,
+                                    arg6,
+                                    arg7,
+                                    arg8,
+                                  );
+}