add solutions to Objects and Classes chapter

docs/answers.md

@@ -38,6 +38,58 @@ const annotateData = (array) => array.reduce(reducer, [])
 const newData = annotateData(data)
 ```
 
+## Objects and Classes
+
+### Delays
+
+```{js}
+class Delay {
+ constructor(initialValue){
+ this.nextValue = initialValue
+ }
+
+ call(nextValue) {
+ let previousValue = this.nextValue
+ this.nextValue = nextValue
+ return previousValue
+ }
+}
+```
+
+### Filtering
+
+```{js}
+class Filter {
+ constructor(...values){
+ this.filterValues = values
+ }
+
+ call(inputValue){
+ return this.filterValues.some((value) => value === inputValue) ? null : inputValue
+ }
+}
+```
+
+### Pipelines
+
+```{js}
+class Pipeline {
+ constructor(...pipes){
+ this.pipes = pipes
+ }
+
+ call(inputValue){
+ let returnValue
+ for (let pipe of this.pipes){
+ returnValue = (() => pipe.call(inputValue))()
+ if (!returnValue) break
+ inputValue = returnValue
+ }
+ return returnValue
+ }
+}
+```
+
 ## Data-Forge
 
 ### Revisting Data Manipulation