ProcLog

A Datalog variant for procedural generation in games, combining Answer Set Programming (ASP) and declarative design.

Syntax Support

• Facts: parent(john, mary).
• Rules: ancestor(X, Z) :- parent(X, Y), ancestor(Y, Z).
• Constraints: :- unsafe(X).
• Negation: not reachable(X, Y)
• Comments:
  • Line comments: % This is a comment
  • Block comments: /* This is a block comment */

Datatypes

ProcLog supports all common datatypes:

1. Integers

• Positive: 42, 100
• Negative: -25, -10
• Zero: 0

2. Floats

• Positive: 3.14, 10.0
• Negative: -2.5

3. Booleans

• True: true
• False: false

4. Strings

• Quoted text: "Hello, World!", "Alice"
• Empty string: ""

5. Atoms

• Lowercase identifiers: john, warrior, treasure_room
• Used for symbolic constants

6. Variables

• Uppercase: X, Y, Player
• Underscore prefix: _tmp, _x, _y

7. Compound Terms

• Nested structures: f(a, b, c)
• Example: inventory(player1, item(sword, 10, 5.5))

Running Tests

cargo test

Running the app

You can start it in REPL mode:

cargo run -q -p proclog-cli -- repl ./examples/01_basic_facts.pl

Or use the built inn test runner:

cargo run -q -p proclog-cli -- test ./examples/01_basic_facts.pl

Example Programs

You'll find examples in the examples/ directory. A brief tour is available in docs/examples_overview.md.

Sampling examples from the CLI

Use the new run subcommand to execute a program once or sample answer sets directly:

# enumerate all stable models
cargo run -q -- run examples/11_loot_loadouts_asp.pl

# sample three loadouts deterministically
cargo run -q -- run --sample 3 examples/11_loot_loadouts_asp.pl

The test subcommand still evaluates embedded #test blocks:

cargo run -q -p proclog-cli -- test examples/*

Development Approach

This project follows Test-Driven Development (TDD):

• Write tests first
• Implement to pass tests
• Refactor as needed

All major components will have comprehensive test coverage before implementation.