feat(validators): add validator for comparision

validators/value.ts → validators/equal.ts

@@ -3,12 +3,12 @@
 
 import { shouldBeBut } from "./utils.ts";
 import { ScalarValidator } from "../utils.ts";
-import type { Assert } from "../types.ts";
+import type { Assert, AssertiveValidator } from "../types.ts";
 
-export class ValueValidator<Out = unknown> extends ScalarValidator
-  implements Assert<unknown, Out> {
-  declare [Assert.symbol]: Out;
-  constructor(public value: Out) {
+export class EqualValidator<const In_ = unknown> extends ScalarValidator
+  implements AssertiveValidator<unknown, In_> {
+  declare [Assert.symbol]: In_;
+  constructor(public value: In_) {
     super();
     super.expect(shouldBeBut);
   }

validators/greater.ts

@@ -0,0 +1,20 @@
+// Copyright 2023-latest Tomoki Miyauchi. All rights reserved. MIT license.
+// This module is browser compatible.
+
+import { ScalarValidator } from "../utils.ts";
+import { shouldBeBut } from "./utils.ts";
+
+export class GreaterValidator<In> extends ScalarValidator<In> {
+  constructor(public base: In) {
+    super();
+    super.expect(shouldBeBut);
+  }
+
+  override is(input: In): boolean {
+    return this.base < input;
+  }
+
+  toString(): string {
+    return `greater then ${this.base}`;
+  }
+}

validators/less.ts

@@ -0,0 +1,20 @@
+// Copyright 2023-latest Tomoki Miyauchi. All rights reserved. MIT license.
+// This module is browser compatible.
+
+import { ScalarValidator } from "../utils.ts";
+import { shouldBeBut } from "./utils.ts";
+
+export class LessValidator<In> extends ScalarValidator<In> {
+  constructor(public base: In) {
+    super();
+    super.expect(shouldBeBut);
+  }
+
+  override is(input: In): boolean {
+    return input < this.base;
+  }
+
+  toString(): string {
+    return `less then ${this.base}`;
+  }
+}