Installation

patch-prolog is built from source. The toolchain is three binaries — plgc (compiler), plgr (REPL), and plgl (language server) — installed together.

Requirements

That last row is the point: the programs plgc produces are standalone. You hand someone the binary and it runs, with no Prolog system installed.

Build and install

just install

This builds the runtime and compiler, then installs all three binaries (plgc, plgr, plgl) with cargo install. To build in place without installing:

just build                 # produces target/release/plgc

Shell completions for plgc:

plgc completions zsh > ~/.zfunc/_plgc      # or: bash | fish | elvish | powershell

Your first program

Create deps.pl — a small build-dependency graph:

depends_on(app, auth).
depends_on(app, ui).
depends_on(auth, crypto).
depends_on(ui, render).
depends_on(render, crypto).

% needs/2 is the transitive closure of depends_on.
needs(X, Y) :- depends_on(X, Y).
needs(X, Y) :- depends_on(X, Z), needs(Z, Y).

Compile it to a native binary and query it — needs/2 walks the graph transitively:

plgc build deps.pl -o deps
./deps --query "needs(app, X)" --format text
# X = auth
# X = ui
# X = crypto
# X = render
# X = crypto

Or skip the explicit build during development — plgc run compiles to a temporary binary and executes it in one step (it still compiles; it never interprets):

plgc run deps.pl --query "needs(app, X)"

To explore interactively, start the REPL:

plgr

plg> depends_on(app, auth).
  defined.  (1 in session)
plg> depends_on(app, ui).
  defined.  (2 in session)
plg> ?- depends_on(app, X).
  X = auth ;
  X = ui .

(At the ; prompt, press ; for the next solution or any other key to stop.)

From here, see Compiler Usage for the full plgc surface and the query wire-contract.