Decode an Opcode to Its Mnemonic

Bytecode Is Just Numbered Instructions

Every virtual machine, from CPython to the JVM to Lua, executes a stream of small integers called opcodes. Opcode 100 might mean `LOAD_CONST`; opcode 23 might mean `BINARY_ADD`. The VM's inner loop reads one number and dispatches to the handler that implements it.

The Dispatch Table

The mapping from number to behavior lives in a table or a giant `switch`. Disassemblers like Python's `dis` module do the reverse mapping so humans can read compiled bytecode. You are building that reverse mapping for a five-instruction VM you will grow throughout this track.

Your tiny ISA for now:

• `PUSH` = 1
• `ADD` = 2
• `SUB` = 3
• `PRINT` = 4
• `HALT` = 5

For example, reading opcode `2` should print `ADD`, and reading `99` should print `UNKNOWN`.

Design Notes

Keep opcode numbering stable once you assign it. Production VMs rarely renumber existing instructions because every compiled artifact in the wild depends on the old mapping. Treat your five-opcode table as a contract you will extend, not replace.

For This Exercise

This exercise asks you to map integers to mnemonic names before you implement the stack machine behind them. You will implement a simple `switch` dispatch table that every later VM task extends with real behavior.