New ANTLR Development Tool : live-coding with boot-clj

[Fred Eisele]

https://github.com/babeloff/boot-antlr4/wiki

This tool is a candidate for http://www.antlr.org/tools.html

Rather than being included as a plug-in to a specific IDE it provides tasks for boot-clj.

Boot is tooling that performs arbitrary tasks, tasks may be composed of other tasks.

This project specifically provides the tasks `antlr4` and `test-rig` which are light wrappers around the `org.antlr.v4.Tool` and `org.antlr.v4.runtime.misc.TestRig` classes.

The intent is to provide a "live-coding" experience without depending on a specific IDE.

This works so long as the IDE has the ability to respond to file updates.

I have used this successfully with: Visual Studio Code, Atom.io and Vim.

Included in the project is a demo application which parses the Antlr4 grammar itself.

I plan on demonstrating how the Antlr grammar may be extended to include literate programming elements.

The following composite task watches a prescribed set of files and when they change it automatically performs a workflow.

(deftask build

[]

(comp

(watch)

(antlr4 :grammar "ANTLRv4Lexer.g4"

:package "org.antlr.parser.antlr4")

(antlr4 :grammar "ANTLRv4LiterateParser.g4"

:package "org.antlr.parser.antlr4"

:visitor true)

(javac)

(test-rig :parser "org.antlr.parser.antlr4.ANTLRv4LiterateParser"

:lexer "org.antlr.parser.antlr4.ANTLRv4Lexer"

:start-rule "literaryGrammarSpec"

:input ["src/antlr4/ANTLRv4Lexer.g4"

"src/antlr4/ANTLRv4Parser.g4"]

:tree true

:postscript true

:tokens true)

(target :dir #{"target"})))

Note that the Lexer contains channels which cause problems with the interpreted parser.

Note also that the test-rig :tree option produces  Clojure EDN style lisp the other options should be obvious as they merely wrap their respective classes.