Author-Facing Commands

These are the commands you interact with directly when working with plcc-ng. Everything else runs behind the scenes.

Daily drivers

Use these to experiment with your language spec at each stage of the pipeline. They all remember the spec file path between invocations — pass -s <path> once and subsequent commands in the same directory pick it up automatically.

plcc-scan

Tokenize source input and print each token in human-readable format. Useful for checking that your lexical rules match what you expect.

echo "42 36 2" | plcc-scan
plcc-scan -s subtract.plcc samples/

plcc-parse

Parse source input and print the parse tree. Useful for verifying that your grammar accepts the input you intend and rejects what it shouldn't.

echo "42 36 2" | plcc-parse
plcc-parse -s subtract.plcc samples/

plcc-parse also has an interactive mode: when no source files are given and stdin is a terminal, it reads input at a >>> prompt and parses each line as you type.

plcc-rep

Read-eval-print loop. Runs your full language spec — scanning, parsing, and executing semantics — and prints the result of each input.

plcc-rep -s subtract.plcc samples/   # evaluate files and exit
plcc-rep -s subtract.plcc            # enter interactive mode

Common options

All commands accept these options:

Option	Effect
`-h`, `--help`	Show usage and exit
`-v`	Increase verbosity (repeat for more detail: `-v`, `-vv`, `-vvv`)
`--verbose-format=FMT`	Verbosity output format: `text` (default) or `json`

Visualization

plcc-diagram

Generate and display a class diagram from your spec file. Shows the classes and inheritance relationships that plcc-ng derives from your syntactic grammar — useful for understanding the object model you'll program against when writing semantics.

plcc-diagram -s subtract.plcc

Requires the plcc-diagram package. If plcc-diagram is not installed, this command will not be available.

Metadata and extension discovery

plcc-version

Print the installed plcc-ng version.

plcc-version

List the language plugins installed on your system. plcc-ng ships with python and java support; this command shows what is available.

plcc-lang-list

plcc-parser-list

List the parser plugins installed on your system. plcc-ng ships with the table parser (LL(1) table-driven); this command shows what is available.

plcc-parser-list

plcc-diagram-list

List the diagram format plugins installed on your system. plcc-ng ships with mermaid and plantuml support.

plcc-diagram-list

Requires the plcc-diagram package.

Extension points

plcc-ng is built around extension points. The language, parser, and diagram plugins you see above are the built-in implementations, but the system is designed so that new plugins can be installed alongside plcc-ng and discovered automatically. See the Language extensions, Parser extensions, and Diagram extensions guides for details.