Concatenative Programming Skill

"Programs are composed by concatenation. The stack is the only state."

Core Concept

In concatenative languages:

1. Stack is the implicit data structure
2. Words (functions) transform the stack
3. Composition = Concatenation — f g means "do f, then g"
4. No variables (mostly) — data flows through stack

3 4 +        \ Push 3, push 4, add → 7 on stack
dup *        \ Duplicate top, multiply → 49

Why It's Strange