vml

This repository contains the source for $V^{-}$ and $P^{+}$, a subset of Verse and a pattern-based language.

The code is the implementation component of An Alternative to Pattern Matching, Inspired by Verse, my undergraduate senior thesis with Norman Ramsey and Milod Kazerounian. The repository also contains the source for the paper. The full paper can be found here.

Dependencies

To build ML Source

mosmlc or mlton is required. Compilation instructions for each are below.

make is required.

To build the paper

latexmk and xelatex are required. simplebnf is the only package that gave install trouble to others; if you have latex build issues due to another package, please open a github issue.

Building

To build ML Source

While in src:

make $progname, where $progname is one of vminus, dtran, or pplus, builds $progname. make by iteslf builds dtran by default.

This build uses mosmlc. If you don't have mosmlc and you do have mlton, make $progname-mlton builds $progname (same as above) with mlton.

For example:

make vminus -> Builds vminus with mosmlc.

make pplus-mlton -> Builds pplus with mlton.

All targets are built into bin.

To build the paper

In tex/thesis: make builds the paper. The builds runs all bibtex passes until it reaches a fix point, so compilation can take a few tens of seconds.

Directory Structure

src: source code for dtran, pplus, and vminus.

tests: testing code. Mostly for parsers; correctness testing yet to be made public.

bin: binaries, including scripts. All compiled binaries live here.

tex: tex source and generated pdfs.

tex/thesis: contains the build of full paper. make compiles it. xelatex is required.

tex/.tex-out: the glut of latex build output lives here.

tex/old: outdated files, or for later use.

tex-tech: source for some of the latex tricks used during paper-writing.

tex-util: latex macros and templates.

futurework: Contains directories that exist as digital reminders for future work.

Running the Code

bin contains the vminus, pplus, and dtran binaries after compilation.

vminus and pplus can be executed as an interpreter or with a filename as a single argument.

dtran is a differentiable compiler, and it takes several arguments: from and to, an optional output file, and any number of input files. Each of from and to, separated by a dash to form a single command-line argument, is a language, and dtran will attempt to compile from from as source to to as target. For example, dtran pp-vm will translate $P^{+}$ to $V^{-}$.

All output is written to stdout, unless an output filename is provided with -o outfile. Outfile specification must come before input files.

Example commands:

dtran pp-vm test.pp -> Translates test.pp to $V^{-}$, writing the result to stdout.

dtran vm-vm -o output.vm test.vm -> Parses test.vm and unparses it into output.vm.

dtran pp-d -o output.d -> Runs dtran as an interpreter that takes in $P^{+}$ code and emits $D$ code to output.d.

dtran pp-pp -> Runs dtran as an interpreter that parses $P^{+}$ code unparses it to stdout.

dtran can also execute programs with the special eval flag:

dtran vm-eval test.vm -> Interprets and evaluates test.vm.

Of course, eval cannot go before the dash. You know better than to try.

All language names can be found by running dtran with no arguments.

dtran has some limitations; an ongoing bugfix means it currently cannot parse $D$. A fix is in progress.

Bugs, limitations, and contributions

If you want to contribute, please open an issue or PR!