circuitdk-lossless-sexpr 0.1.1

A lossless concrete syntax tree and text editing library for S-expressions

circuitdk-lossless-sexpr

circuitdk-lossless-sexpr provides a small, lossless concrete syntax tree for S-expressions. Parsing and rendering an unchanged document preserves its source text byte for byte, including whitespace, comments, number formatting, and unknown syntax.

The distribution is maintained as part of CircuitDK, but the Python package can be used independently.

Installation

uv add circuitdk-lossless-sexpr

Usage

from lossless_sexpr import TextEdit, apply_edits, parse

source = '(property "Value" "10 k" (at 1 2))'
document = parse(source)

value = document.lists("property")[0].atom(2)
assert value is not None

updated = apply_edits(source, [TextEdit(value.span, '"47 k"')])
assert updated == '(property "Value" "47 k" (at 1 2))'

Overlapping edits are rejected, and parse errors include source locations. The library deliberately contains no KiCad or circuit-specific semantics.