excerpt

Derives a short, readable excerpt from a longer text — for a card, header or preview where a full paragraph does not fit.

Unlike truncate (a mechanical cut at exactly max_chars), this prefers to cut at the end of a whole sentence (., ! or ?) when one fits within max_chars, even if that leaves the result shorter than the limit. Only when no sentence fits does it fall back to the last whole word before the limit — it never returns partial-word text.

Internal whitespace (line breaks, repeated spaces) is collapsed to single spaces first (see squish).

Known limitation: the sentence-boundary check is a simple heuristic (punctuation followed by whitespace or the end of the text) — it does not special-case abbreviations ("Mr.") or decimal numbers ("3.14"), which can be misread as a sentence end.

Import

use helpers4::string::excerpt;

Cargo feature string (enabled by default). To compile only this module:

cargo add helpers4 --no-default-features --features string

or in Cargo.toml:

[dependencies]
helpers4 = { version = "0.0.7", default-features = false, features = ["string"] }

Signature

pub fn excerpt(text: &str, max_chars: usize, ellipsis: &str) -> String

Parameters

Parameter	Type	Description
text	&str	The text to excerpt.
max_chars	usize	The maximum length of the result, ellipsis included.
ellipsis	&str	Appended only when falling back to a word-boundary cut (a sentence-boundary cut never needs one).

Returns

String — The original text, squished, unchanged if already within max_chars; otherwise a shortened version.

Examples

use helpers4::string::excerpt;

assert_eq!(excerpt("A short game about ducks.", 200, "…"), "A short game about ducks.");

assert_eq!(
    excerpt("Build the biggest, best theme park ever seen. Can you make money?", 47, "…"),
    "Build the biggest, best theme park ever seen.",
);

assert_eq!(
    excerpt("This description has no punctuation at all so it must cut on a word", 30, "…"),
    "This description has no…",
);

Source

src/string/excerpt.rs