bare-script

BareScript is a simple, lightweight, and portable programming language. Its Pythonic syntax is influenced by JavaScript, C, and the Unix Shell. BareScript also has a library of built-in functions for common programming operations. BareScript can be embedded within applications or used as a stand-alone programming language using the command-line interface.

There are two implementations of BareScript: BareScript for Python (this package) and BareScript for JavaScript. Both implementations have 100% unit test coverage with identical unit test suites, so you can be confident that BareScript will execute the same regardless of the underlying runtime environment.

Links

• The BareScript Language
• The BareScript Library
• The BareScript Include Library Tests
• API Documentation
• Source code

Executing BareScript Scripts

To execute a BareScript script, parse the script using the parse_script function. Then execute the script using the execute_script function. For example:

from bare_script import execute_script, parse_script

# Parse the script
script = parse_script('''\
# Double a number
function double(n):
    return n * 2
endfunction

return N + ' times 2 is ' + double(N)
''')

# Execute the script
globals = {'N': 10}
print(execute_script(script, {'globals': globals}))

This outputs:

10 times 2 is 20

The BareScript Library

The BareScript Library includes a set of built-in functions for mathematical operations, object manipulation, array manipulation, regular expressions, HTTP fetch and more. The following example demonstrates the use of the systemFetch, objectGet, and arrayLength functions.

import urllib.request

from bare_script import execute_script, fetch_http, parse_script

# Parse the script
script = parse_script('''\
# Fetch the BareScript builtin library documentation JSON
docs = jsonParse(systemFetch('https://craigahobbs.github.io/bare-script-py/library/library-builtin.json'))

# Return the number of builtin functions
return 'The BareScript Library has ' + arrayLength(objectGet(docs, 'functions')) + ' builtin functions'
''')

# Execute the script
print(execute_script(script, {'fetchFn': fetch_http}))

This outputs:

The BareScript Library has 108 builtin functions

Evaluating BareScript Expressions

To evaluate a BareScript expression, parse the expression using the parse_expression function. Then evaluate the expression using the evaluate_expression function.

Expression evaluation includes the BareScript Expression Library, a set of built-in, spreadsheet-like functions.

For example:

from bare_script import evaluate_expression, parse_expression

# Parse the expression
expr = parse_expression('2 * max(a, b, c)')

# Evaluate the expression
variables = {'a': 1, 'b': 2, 'c': 3}
print(evaluate_expression(expr, None, variables))

This outputs:

6

The BareScript Command-Line Interface (CLI)

You can run BareScript from the command line using the BareScript CLI, "bare". BareScript script files use the ".bare" file extension.

bare script.bare

Note: In the BareScript CLI, import statements and the systemFetch function read non-URL paths from the local file system. systemFetch calls with a non-URL path and a request body write the body to the path.

MarkdownUp, a Markdown Viewer with BareScript

MarkdownUp is a Markdown Viewer that executes BareScript embedded within Markdown documents. The MarkdownUp runtime contains functions for dynamically rendering Markdown text, drawing SVG images, etc. For example:

# Markdown Application

This is a Markdown document with embedded BareScript:

``` markdown-script
markdownPrint('Hello, Markdown!')
```

C Runtime

The package ships with an optional CPython C extension, runtime_c, that mirrors the pure-Python runtime for faster script execution. The compiled extension is used automatically when available; set the environment variable BARESCRIPT_RUNTIME_PY=1 to force the pure-Python runtime.

The extension supports CPython 3.10 and later on both the default (GIL) and free-threaded Python builds.

The C runtime runs the BareScript include library test suite (make test-include) about 3.6x faster than the pure-Python runtime (CPython 3.14, Apple M-series):

Compute-intensive scripts run up to roughly 30x faster - for example, the Mandelbrot benchmark (make perf), shown here against the equivalent native Python program:

Using BareScript with an AI Assistant

This repository ships a SKILL.md file that teaches an AI coding assistant how to write idiomatic BareScript — language syntax, the built-in and include libraries, the MarkdownUp application pattern, and the unit-test conventions. It is plain Markdown and applies to either BareScript implementation.

For Claude Code and other tools that follow the Agent Skills convention, install it as a project or user skill:

mkdir -p .claude/skills/bare-script
cp SKILL.md .claude/skills/bare-script/SKILL.md

Use ~/.claude/skills/bare-script/SKILL.md instead to make it available across all projects. For other assistants, include the file's contents in your system prompt or rules file.

Once installed, prompt the assistant with a task like:

claude "Build a MarkdownUp application that plays tic-tac-toe against the user, with a reset button and a running win/loss/draw tally rendered as a bar chart. Save it as ticTacToe.md"

To run the resulting MarkdownUp application locally, install the markdown-up viewer and point it at the Markdown file:

pip install markdown-up
markdown-up ticTacToe.md

The BareScript library is also documented as single-page Markdown, which can be fetched directly into an assistant's context alongside SKILL.md:

• The BareScript Library
• The BareScript Library Models

Development

This package is developed using python-build. It was started using python-template as follows:

template-specialize python-template/template/ bare-script-py/ -k package bare-script -k name 'Craig A. Hobbs' -k email 'craigahobbs@gmail.com' -k github 'craigahobbs'