jcompiler

A compiler for the J array programming language.

Getting Started

To build jCompiler, you will need:

• a stable version of Rust
• LLVM 10 and Clang 10 (see scripts/install-llvm-backend-dependencies.sh)

To develop jCompiler, you will want to run the tests, which introduce additional dependencies on:

• ijconsole, the J language interpreter (see scripts/install-common-dependencies.sh)
• Linaro, to cross-assemble and link binaries on an x86_64 development machine, and qemu to run them (see scripts/install-arm-backend-dependencies.sh)

The CircleCI job definitions in this repo invoke the scripts mentioned above when preparing test environments, so they are the authoritative resources as to what exactly is required.

Using the LLVM Backend

$ cargo build --release
$ target/release/jcompiler --backend=llvm <jfile>.ijs
$ ./<jfile>

By default, LLVM use the target architecture of the host machine. You can explicitly choose a target architecture using LLVM target triples:

$ target/release/jcompiler <jfile>.ijs --target=x86_64-pc-linux-gnu

Using the ARM Backend

$ cargo build --release
$ target/release/jcompiler --backend=arm <jfile>.ijs
$ ./<jfile>

Note: the output emitted by this backend most closely matches the godbolt.org configuration "ARM gcc 7.2.1 (none)" with options "-O0 -mfloat-abi=hard".

Examples

You can find many examples of J programs in the jlang_programs directory. As one example, compiling this J program:

'Some array operations...'
*: 1 2 3 4
matrix =: 2 3 $ 5 + 2 3 4 5 6 7
10 * matrix
1 + 10 20 30
1 2 3 + 10
residues =: 2 | 0 1 2 3 4 5 6 7
residues

with jcompiler and running the compiled binary will yield the following on stdout:

Some array operations...
1 4 9 16
 70  80  90
100 110 120
11 21 31
11 12 13
0 1 0 1 0 1 0 1

Documentation

The API reference for the master branch is available here, but is out-of-date and incomplete at the moment.