QuestForth

Interactive text quests powered by a small Forth-like scripting language, a Qt 6 player, and a desktop quest editor.

Language reference: LANGUAGE.md

Sample quests under quests/ are written in Ukrainian; the engine, docs, and tools use English.

Features

• Stack VM with integers, reals, strings, arrays, and objects
• Scenes, choices, inventory, variables, save/load
• Loops (BEGIN/UNTIL, BEGIN/WHILE/REPEAT, DO/LOOP), colon definitions
• Optional canvas drawing and DELAY
• Qt Quick player with catalog menu
• Qt Widgets editor: highlighting, autocomplete, hover help, breakpoints, step debugger
• Headless tests (Catch2) and validate_quests for batch compile checks

Requirements

• C++23 compiler (GCC 13+ / Clang 16+ recommended)
• CMake 3.16+
• Qt 6.2+ (Quick for the player, Widgets for the editor)
• Catch2 is fetched automatically for tests

Build

cmake -S . -B build -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_PREFIX_PATH="$HOME/Qt/6.x.x/gcc_64"   # if Qt is not on the default path
cmake --build build -j

Targets:

Binary	Role
QuestForth	Quest player (Qt Quick)
QuestForthEditor	Script editor / debugger (Qt Widgets)
test_engine	Unit tests
validate_quests	Compile-check quest files

Without Qt, engine tests and validate_quests still build.

Run

./build/QuestForth
./build/QuestForthEditor quests/warmup/01_lost_badge.forth
./build/test_engine
./build/validate_quests quests

Project layout

compiler.* vm.* words.* value.* init.h   engine
GameController.* main.cpp main.qml       player
editor/                                  quest editor
quests/                                  sample scenarios
tests/                                   Catch2 suite
tools/validate_quests.cpp                batch validator
LANGUAGE.md                              language spec

Contributing

• Keep engine comments and docs in English.
• Do not add CI auto-deploy workflows unless agreed.
• Quest content may stay in the author’s language; leave existing quests/*.forth stories intact unless intentionally rewriting them.

License

GNU GPL v3 — see LICENSE.

Copyright (C) 2026 Ihor Dolinskyi

QuestForth uses Qt. Qt is a trademark of The Qt Company Ltd. and is available under LGPLv3, GPLv3, and commercial licenses. See Qt licensing. Third-party build dependencies (Catch2) — NOTICE.