add day 20

Author: zyhou

2024/20/index.ts

@@ -0,0 +1,69 @@
+import type { Expect, Equal } from "type-testing";
+
+type AnalyzeScope<T> = T extends `${" " | "\n" | "\t" | "\r"}${infer Tail}`
+  ? AnalyzeScope<Tail>
+  : T extends `${"let" | "const" | "var"} ${infer Variable} = "${string}";${infer Tail}`
+    ? {
+        declared: [Variable, ...AnalyzeScope<Tail>["declared"]];
+        used: AnalyzeScope<Tail>["used"];
+      }
+    : T extends `${string}(${infer Param});${infer Tail}`
+      ? {
+          declared: AnalyzeScope<Tail>["declared"];
+          used: [Param, ...AnalyzeScope<Tail>["used"]];
+        }
+      : { declared: []; used: [] };
+
+// ------------------- Test section ---------------------
+
+type t0_actual = AnalyzeScope<`
+let teddyBear = "standard_model";
+`>;
+interface t0_expected {
+  declared: ["teddyBear"];
+  used: [];
+}
+type t0 = Expect<Equal<t0_actual, t0_expected>>;
+
+type t1_actual = AnalyzeScope<`
+buildToy(teddyBear);
+`>;
+interface t1_expected {
+  declared: [];
+  used: ["teddyBear"];
+}
+type t1 = Expect<Equal<t1_actual, t1_expected>>;
+
+type t2_actual = AnalyzeScope<`
+let robotDog = "deluxe_model";
+assembleToy(robotDog);
+`>;
+interface t2_expected {
+  declared: ["robotDog"];
+  used: ["robotDog"];
+}
+type t2 = Expect<Equal<t2_actual, t2_expected>>;
+
+type t3_actual = AnalyzeScope<`
+  let robotDog = "standard_model";
+  const giftBox = "premium_wrap";
+    var ribbon123 = "silk";
+
+  \t
+  wrapGift(giftBox);
+  \r\n
+      addRibbon(ribbon123);
+`>;
+interface t3_expected {
+  declared: ["robotDog", "giftBox", "ribbon123"];
+  used: ["giftBox", "ribbon123"];
+}
+type t3 = Expect<Equal<t3_actual, t3_expected>>;
+
+type t4_input = "\n\t\r \t\r ";
+type t4_actual = AnalyzeScope<t4_input>;
+interface t4_expected {
+  declared: [];
+  used: [];
+}
+type t4 = Expect<Equal<t4_actual, t4_expected>>;