outside

Documentation

Overview

Package outside makes text that came from outside safe to hand on: a release's name as a public indexer gave it, a file's name, a title or a description fetched from a service anyone can write to.

Such text is written by strangers and read by a model, which takes what it reads as it finds it. What cannot be seen is the easiest to hide an instruction in, and what runs on for pages the easiest to bury one in, so Text takes out the characters that do not show or that change how the rest is shown, and cuts what is left to a length. It does not judge what the words say: what is left is still a stranger's, and is data, not instructions.

Clean what is read, not what is handed back. A value a later call takes as an argument - a path a scan listed, a release's id, a folder's name - has to go back as it came, or it no longer finds the thing it names: a file whose name holds a character that does not show is not found by the name without it. Leave such a value as it is, or look the thing up by the cleaned form.

Index

• func Text(s string, limit int) string

Functions

func Text

func Text(s string, limit int) string

Text is s with what does not show taken out, and no longer than limit characters, ending in an ellipsis where it was cut; a limit of 0 or less is no limit.

Taken out is every character that does not show: the control characters, of which a tab, a line break or the like becomes a space, so the words either side of one stay apart; the format characters, which are the zero-width ones, the joiners, the soft hyphen and the marks, embeddings, overrides and isolates of the direction text runs in, which can show a line as other than it is; the tag characters and the variation selectors, either of which can carry a hidden message after any letter; and the fillers that stand where a letter would and show as nothing. Letters, marks and spaces of every script are left as they are. An emoji loses the selector that asks for its coloured form, and shows as its viewer draws it without one.