L10 Logic Programming Language

This is a source repository for the L10 programming language. It contains a lot of stuff, the most interesting of which (currently) is the Elton compiler from L10 to Standard ML. There are also lots of pieces of a compiler from L10 to the X10 distributed programming language. See the GitHub wiki for more.

Elton, the L10-to-Standard ML Compiler

Installation

Elton depends on CMlib version 1, which can be installed with Smackage. Once you already have smackage, it's easiest to install Elton through smackage:

$ smackage get elton
$ smackage make elton mlton # or "smackage make elton smlnj"
$ smackage make elton install
$ elton examples/EdgePath1.l10

You can also built Elton by downloading the source directly:

$ make 
Elton - a compiler from L10 to Standard ML
Run 'make mlton' or 'make smlnj' or 'make check'
$ make mlton
$ bin/elton examples/EdgePath1.l10

Use

The commands elton examples/EdgePath1.l10 (Smackage installation) and bin/elton examples/EdgePath1.l10 (source installation) read the file EdgePath1.l10...

edge: string -> string -> rel.
path: string -> string -> rel.

edge X Y -> path X Y.
edge X Y, path Y Z -> path X Z.

example = edge "a" "b", edge "b" "c", edge "b" "d", edge "a" "e", edge "d" "f".

... and create a file EdgePath1.l10.sml. This Elton-generated file contains a structure EdgePath1 satisfying the following signature:

signature EDGE_PATH1 =
sig
   type db (* Type of L10 databases *)
   val empty: db
   val example: db

   type string    = String.string (* builtin *)
   type nat       = IntInf.int (* builtin *)

   structure Assert:
   sig
      val path: (string * string) * db -> db
      val edge: (string * string) * db -> db
   end

   structure Query:
   sig
      val path: db -> (string * string) -> bool
      val edge: db -> (string * string) -> bool
   end
end

The signature EDGE_PATH1 appears at the top of the Elton-generated file EdgePath1.l10.sml.

The generated code from Elton depends on the CMlib version 1, which can be obtained with Smackage. It can be run like this:

$ sml '$SMACKAGE/cmlib/v1/cmlib.cm' examples/EdgePath1.l10.sml
<snip>
- EdgePath1.Query.edge EdgePath1.example ("a", "f");
val it = false : bool
- EdgePath1.Query.path EdgePath1.example ("a", "f");
val it = true : bool