fix(front, back) -> undefined exception; feat(resize)

src/List.js

@@ -35,6 +35,16 @@ export class List {
     return this._end.clone()
   }
 
+  resize(size, value) {
+    if (this._size > size)
+      while (this._size !== size)
+        this.popBack()
+
+    else
+      while (this._size !== size)
+        this.pushBack(value)
+  }
+
   _shiftRight(dest, generator) {
     let prev, res, new_item, item = dest.deref()
 
@@ -75,7 +85,7 @@ export class List {
   }
 }
 
-List.from = function (obj) {
+List.from = function(obj) {
   const list = new List()
   for (const value of obj) {
     list.pushBack(value)
@@ -98,6 +108,7 @@ export class ListItem {
 }
 
 export class ListIterator {
+
   constructor(item) {
     this._item = item
   }
@@ -130,4 +141,4 @@ export class ListIterator {
   }
 }
 
-mixinClasses(ListIterator, BidirectionalIterator)
+mixinClasses(ListIterator, BidirectionalIterator)

src/containers/Sequence.js

@@ -1,5 +1,5 @@
 import { BidirectionalIterator } from "../iterators/Bidirectional"
-import { satisfiesConcept } from "../utils/concept"
+import { getCloneFunc, satisfiesConcept } from "../utils/concept"
 
 export class SequenceContainer {
   clone() {
@@ -16,6 +16,9 @@ export class SequenceContainer {
   }
 
   get front() {
+    if (this.empty())
+      throw new Error('front element is undefined')
+
     return this.begin().value
   }
 
@@ -24,6 +27,9 @@ export class SequenceContainer {
   }
 
   get back() {
+    if (this.empty())
+      throw new Error('back element is undefined')
+
     return this.end().dec().value
   }
 
@@ -151,10 +157,11 @@ export class SequenceContainer {
   }
 }
 
-SequenceContainer.is = function (obj, ...args) {
+SequenceContainer.is = function(obj, ...args) {
   const pure_virtual = [
     'move',
     'size',
+    'resize',
     'begin',
     'end',
     '_shiftRight',
@@ -179,4 +186,4 @@ SequenceContainer.is = function (obj, ...args) {
     'toString',
   ]
   return satisfiesConcept(obj, pure_virtual, virtual, ...args)
-}
+}

src/iterators/Forward.js

@@ -6,7 +6,7 @@ export class ForwardIterator {
   }
 
   get value() {
-    return this.deref()?.value
+    return this.deref().value
   }
 
   set value(value) {
@@ -32,4 +32,4 @@ ForwardIterator.is = function (obj, ...args) {
     'neq',
   ]
   return satisfiesConcept(obj, pure_virtual, virtual, ...args)
-}
+}

src/utils/concept.js

@@ -31,4 +31,4 @@ export function satisfiesConcept(obj, pure_virtual, virtual, debug) {
     }
   }
   return true
-}
+}

src/utils/mixin.js

@@ -4,4 +4,4 @@ export function mixinClasses(dest, ...sources) {
     delete properties.constructor
     Object.defineProperties(dest.prototype, properties)
   }
-}
+}