Wrap text at a column width

Fixed-width text has not gone away. Commit message bodies are conventionally wrapped at 72 columns, plain-text email still expects a hard wrap, and plenty of code review tools, changelogs, README files and terminal output are read at a fixed width whether or not anyone wrote them that way.

The default here is 72 columns, which is the convention for a commit body and leaves room for the indentation that a mail client or a git log adds when quoting it.

The choice that changes the result most is whether to reflow. Reflowing joins each paragraph back into one run of text and then breaks it at the chosen width, which is what prose needs: text that was previously wrapped at a different width comes out wrapped at the new one, with no trace of where the old breaks were. Blank lines separate paragraphs and are preserved, so the structure survives while the line breaks inside it are rebuilt.

Wrapping each line where it already sits does the opposite. It leaves the existing line structure alone and only breaks lines that are too long. This is the mode for anything that is already laid out deliberately, where joining lines would destroy the layout: a list, a table of contents, a block of code, or text whose line breaks are meaningful.

Long words are the only genuinely difficult case. A URL, a long identifier or a file path can easily exceed the whole column width, and there are two ways to handle it. Breaking it produces a tidy right margin and a link that no longer works when clicked or copied. Keeping it whole produces one line that overshoots the column. FileGizmo keeps it whole by default, on the grounds that an overshooting line is visible to whoever is looking at the text while a silently broken URL is not. Breaking is available for the cases where the column really is a hard limit.

The wrapping itself is greedy: each line takes as many words as fit and then breaks. More sophisticated algorithms balance the ragged edge across the whole paragraph and produce a visibly nicer margin, but no editor does that, so the output would stop matching what the same text looks like anywhere else. Agreeing with the tools around it is worth more than the prettier margin.

The result reports the number of lines produced and the width they were wrapped to. Nothing is uploaded.