Tags » Lazy Evaluation

A mimic of pipeline implementation in jdk 8 stream

Here a complete program is provided to show how pipeline is implemented which replicates the part of the diagram in previous post. The test below is demonstrated with an efficient stream style. 676 more words

A Note on Lazy Evaluation in R

R is commonly thought of as a functional programming language. If you associate functional programming (FP) with lambda calculus and pure FP languages like Haskell, then you may get surprised by aspects of R’s computational model. 134 more words

Data Science

Be(a)ware of Laziness

Let’s assume we have a simple JavaScript “class” called Module. Each instance of the class has a name, a start() method and a stop() 502 more words

Software Development

Scala: Lazy vs Non-Lazy evaluations

Function is a first class citizen in Scala, therefore lazy evaluation feels very intuitive and handy in many situations. However recently I encountered a situation where lazy evaluation could be catastrophic if we’re not careful. 876 more words


How lazy is compiled in Scala

Scalaのlazyというkeywordはどのように実装されているのかを見てみます。確認したプログラムは以下のシンプルなもので、lzというフィルドはlazy valによって宣言されています。

class Foo {
  lazy val lz = 5


public class Foo
  private int lz;
  private volatile boolean bitmap$0;

  private int lz$lzycompute()
    synchronized (this) {
      if (!this.bitmap$0) { this.lz = 5; this.bitmap$0 = true;}
      return this.lz;
  public int lz() { 
      return this.bitmap$0 ? 13 more words

Python Generators (Part 2)

So what, then, are the benefits of using generators over regular list-returning functions? The answer is lazy evaluation, and below I’ll give you a few examples of how laziness can be much better than “thoroughness”… 1,158 more words