add new option/result methods

src/option.js

@@ -105,33 +105,24 @@ export class Some extends Option {
    * @param {(value: T) => Option<T>} fn
    * @returns {Option<T>}
    */
-  bind(fn) {
+  andThen(fn) {
     return fn(this.#value)
   }
 
-  /**
-   * @template V
-   * @param {(value: T) => V} fn
-   * @returns {Option<V>}
-   */
-  map(fn) {
-    return new Some(fn(this.#value))
-  }
-
   /**
    * @param {Option<T>} other
    * @returns {Option<T>}
    */
-  alt(_other) {
+  and(other) {
-    return this
+    return other
   }
 
   /**
-   * @param {Some<T>} other
+   * @param {Option<T>} other
-   * @returns {Some<T>}
+   * @returns {Option<T>}
    */
-  and(other) {
+  or(_other) {
-    return other
+    return this
   }
 
   /**
@@ -188,6 +179,35 @@ export class Some extends Option {
     }
   }
 
+  /**
+   * @template V
+   * @param {(value: T) => V} fn
+   * @returns {Option<V>}
+   */
+  map(fn) {
+    return new Some(fn(this.#value))
+  }
+  
+  /**
+   * @template V
+   * @param {V} _default
+   * @param {(value: T) => V} fn
+   * @returns {V}
+   */
+  mapOr(_default, fn) {
+    return this.map(fn)
+  }
+
+  /**
+   * @template V
+   * @param {() => V} _defaultFn
+   * @param {(value: T) => V} fn
+   * @returns {V}
+   */
+  mapOrElse(_defaultFn, fn) {
+    return this.map(fn)
+  }
+
   /**
    * @template E
    * @param {E} _err
@@ -263,21 +283,20 @@ class _None extends Option {
 
   /**
    * @template T
-   * @template {Option<T>} R
+   * @param {Option<T>} _other
-   * @param {(value: T) => R} fn
+   * @returns {Option<T>}
-   * @returns {R}
    */
-  bind(_fn) {
+  and(_other) {
     return this
   }
 
   /**
-   * @template V
+   * @template T
    * @template {Option<T>} R
-   * @param {(value: T) => V} fn
+   * @param {(value: T) => R} fn
    * @returns {R}
    */
-  map(_fn) {
+  andThen(_fn) {
     return this
   }
 
@@ -286,7 +305,7 @@ class _None extends Option {
    * @param {Option<T>} other
    * @returns {Option<T>}
    */
-  alt(other) {
+  or(other) {
     return other
   }
 
@@ -299,15 +318,6 @@ class _None extends Option {
     return fn()
   }
 
-  /**
-   * @template T
-   * @param {Some<T>} _other
-   * @returns {Some<T>}
-   */
-  and(_other) {
-    return this
-  }
-
   /**
    * @template T
    * @param {(value: T) => bool} _predicate
@@ -354,6 +364,36 @@ class _None extends Option {
     return this
   }
   
+  /**
+   * @template V
+   * @template {Option<T>} R
+   * @param {(value: T) => V} fn
+   * @returns {R}
+   */
+  map(_fn) {
+    return this
+  }
+
+  /**
+   * @template V
+   * @param {V} defaultValue
+   * @param {(value: T) => V} _fn
+   * @returns {V}
+   */
+  mapOr(defaultValue, _fn) {
+    return defaultValue
+  }
+
+  /**
+   * @template V
+   * @param {() => V} defaultFn
+   * @param {(value: T) => V} _fn
+   * @returns {V}
+   */
+  mapOrElse(defaultFn, _fn) {
+    return defaultFn()
+  }
+
   /**
    * @template T, E
    * @template {Result<T, E>} R
@@ -429,10 +469,10 @@ implementor(Some)
   .implements(...structures)
   .specifiedBy(FantasyLand)
   .with({
-    chain: Some.prototype.bind,
+    chain: Some.prototype.andThen,
     filter: Some.prototype.filter,
     map: Some.prototype.map,
-    alt: Some.prototype.alt,
+    alt: Some.prototype.or,
     equals: Some.prototype.equals,
     lte: Some.prototype.lte,
   })
@@ -441,10 +481,10 @@ implementor(_None)
   .implements(...structures)
   .specifiedBy(FantasyLand)
   .with({
-    chain: _None.prototype.bind,
+    chain: _None.prototype.andThen,
     filter: _None.prototype.filter,
     map: _None.prototype.map,
-    alt: _None.prototype.alt,
+    alt: _None.prototype.or,
     equals: _None.prototype.equals,
     lte: _None.prototype.lte,
   })

src/result.js

@@ -75,7 +75,7 @@ export class Ok extends Result {
    * @param {(value: T) => R} fn
    * @returns {R}
    */
-  bind(fn) {
+  andThen(fn) {
     return fn(this.#value)
   }
 
@@ -89,6 +89,26 @@ export class Ok extends Result {
     return Result.ok(fn(this.#value))
   }
 
+  /**
+   * @template V
+   * @param {V}  _defaultValue
+   * @param {(value: T) => V} fn
+   * @returns {V}
+   */
+  mapOr(_defaultValue, fn) {
+    return this.map(fn)
+  }
+
+  /**
+   * @template V
+   * @param {() => V}  _defaultFn
+   * @param {(value: T) => V} fn
+   * @returns {V}
+   */
+  mapOr(_defaultFn, fn) {
+    return this.map(fn)
+  }
+
   /**
    * @template E
    * @param {Result<T, E>} other
@@ -103,7 +123,7 @@ export class Ok extends Result {
    * @param {Result<T, E>} other
    * @returns {Result<T, E>}
    */
-  alt(_other) {
+  or(_other) {
     return this
   }
 
@@ -249,20 +269,40 @@ export class Err extends Result {
    * @param {(value: T) => R} fn
    * @returns {R}
    */
-  bind(_fn) {
+  andThen(_fn) {
     return this
   }
 
   /**
    * @template V, E
    * @template {Result<V, E>} R
-   * @param {(value: T) => V} fn
+   * @param {(value: T) => V} _fn
    * @returns {R}
    */
   map(_fn) {
     return this
   }
 
+  /**
+   * @template V
+   * @param {V} defaultValue
+   * @param {(value: T) => V} _fn
+   * @returns {V}
+   */
+  mapOr(defaultValue, _fn) {
+    return defaultValue
+  }
+
+  /**
+   * @template V
+   * @param {() => V} defaultFn
+   * @param {(value: T) => V} _fn
+   * @returns {V}
+   */
+  mapOrElse(defaultFn, _fn) {
+    return defaultFn()
+  }
+
   /**
    * @template T
    * @param {Result<T, E>} _other
@@ -277,7 +317,7 @@ export class Err extends Result {
    * @param {Result<T, E>} other
    * @returns {Result<T, E>}
    */
-  alt(other) {
+  or(other) {
     return other
   }
 
@@ -405,10 +445,10 @@ implementor(Ok)
   .implements(...structures)
   .specifiedBy(FantasyLand)
   .with({
-    chain: Ok.prototype.bind,
+    chain: Ok.prototype.andThen,
     map: Ok.prototype.map,
     reduce: Ok.prototype.reduce,
-    alt: Ok.prototype.alt,
+    alt: Ok.prototype.or,
     equals: Ok.prototype.equals,
     lte: Ok.prototype.lte,
   })
@@ -417,10 +457,10 @@ implementor(Err)
   .implements(...structures)
   .specifiedBy(FantasyLand)
   .with({
-    chain: Err.prototype.bind,
+    chain: Err.prototype.andThen,
     map: Err.prototype.map,
     reduce: Err.prototype.reduce,
-    alt: Err.prototype.alt,
+    alt: Err.prototype.or,
     equals: Err.prototype.equals,
     lte: Err.prototype.lte,
   })