Posts (238+)

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May 2026

Bi-Arity:Two Arguments Without a Pair Type

Use BiFunction, BiPredicate, and BiConsumer for two-argument slots — apply, test, accept — and fill Map.merge, compute, and forEach without inventing a pair type.

Linux

Linux grep:Search Files Like You Mean It

Hands-on grep recipes for everyday work — find text, filter logs, search codebases, and pipe results with confidence.

Java

Unary and Binary Operators:Same Type In, Same Type Out

Use UnaryOperator and BinaryOperator when input and output are the same type — List.replaceAll, Stream.reduce, Collectors.reducing, and minBy / maxBy.

Java

Supplier:Produce a Value When Asked

Use Java’s Supplier<T> for lazy values — get, orElseGet, factories, supplyAsync — so you do not build work until something actually needs the result.

Java

Consumer:Accept a Value for a Side Effect

Use Java’s Consumer<T> for side effects — accept, andThen — and see where Stream.forEach, Optional.ifPresent, and peek already ask for it.

Java

Predicate:Ask a Yes/No Question You Can Combine

Use Java’s Predicate<T> to test values — test, and, or, negate, isEqual, Predicate.not (Java 11) — and see where Stream.filter, anyMatch, and removeIf already ask for it.

Linux

Linux Common Directories:Know Where Things Live

Learn the Linux filesystem hierarchy — what /, /etc, /var, /usr, /home and friends are for, and when to look in each one.

Java

Function:Turn T into R Without a One-Off Interface

Use Java’s Function<T,R> to map values — apply, compose, andThen, identity — and see where Stream.map, Optional.map, and Collectors already ask for it.

Java

Functional Interfaces Roadmap:The Four Shapes Behind Every Lambda

What a Java functional interface is, the four shapes in java.util.function, when to write your own SAM type, and a living map of every post in this series.