Configuration¶

Project config file¶

Snapper looks for .snapperrc.toml starting from the current directory and walking up to the filesystem root. Override the search with --config path/to/config.toml.

Or generate one with snapper init.

Config format¶

# Language for abbreviation sets (en, de, fr, is, pl)
lang = "en"

# Extra abbreviations (merged with built-in list for the selected language)
extra_abbreviations = ["GROMACS", "LAMMPS", "DFT"]

# File patterns to ignore (glob syntax)
ignore = ["*.bib", "*.cls", "*.sty"]

# Default format (overridden by --format flag)
format = "org"

# Maximum line width (0 = unlimited, overridden by --max-width flag)
max_width = 0

# Per-format overrides
[org]
extra_abbreviations = ["PROPERTIES", "DEADLINE"]

[latex]
extra_abbreviations = ["Thm", "Lem"]
max_width = 100

# Per-language code-block comment reflow and optional formatters.
# Used when the parser emits a Region::Code with a matching language.
# --format-code runs `formatter` on the block body after comment reflow.
[code.rust]
line_comment = "//"
block_comment = ["/*", "*/"]
formatter = ["rustfmt", "--edition", "2024"]

[code.python]
line_comment = "#"
block_comment = ["\"\"\"", "\"\"\""]
formatter = ["ruff", "format", "-"]

Fields¶

lang¶

String. Language code for the built-in abbreviation set used by the rule-based splitter. One of: en (default), de, fr, is, pl. Also selectable via --lang CLI flag.

extra_{abbreviations}¶

String array. Each entry names an abbreviation that should not trigger a sentence break when followed by a period. Merged with the built-in list for the selected language. Useful for domain-specific terms your papers use frequently.

ignore¶

String array of glob patterns. Files matching these patterns get skipped during --in-place and --check operations. Does not affect stdin/stdout mode.

format¶

String. Default format when auto-detection from file extension does not apply. One of: org, latex, markdown, rst, plaintext.

max_width¶

Integer. Sentences exceeding this width get wrapped at word boundaries. Set to 0 for unlimited (the default). Also respects max_line_length from .editorconfig if present.

Per-format sections¶

Add [org], [latex], [markdown], [rst], or [plaintext] sections to override settings for specific formats.

Per-format extra_abbreviations merge with the top-level list. Per-format max_width overrides the top-level value.

Code-block sections (`[code.<lang>]`)¶

Each [code.<lang>] table configures how fenced or delimited source blocks for that language are handled. snapper init writes seed entries for common languages (rust, python, toml, lua, lisp, html, javascript).

line_comment¶

String. Marker for single-line comments (for example "//" or "#"). Comment text after the marker is reflowed with the sentence splitter; the marker and indentation are preserved.

block_comment¶

String array of length two: open and close markers (for example ["/*", "*/"]). One-line and multi-line block comments are reflowed as prose between the markers.

formatter¶

String array treated as argv for std::process::Command. Only runs when the CLI flag --format-code is set. Missing binaries, non-zero exits, and a ~30s watchdog timeout each leave the reflowed body in place (non-fatal).

If a language has no [code.<lang>] entry (or the fence has no language), the block body passes through unchanged aside from normal trailing-newline preservation.

Precedence¶

CLI flags override config file values. Per-format sections override top-level config values. Config file values override .editorconfig values. .editorconfig overrides built-in defaults.