zipper package:reflex-vty

TextZipper is designed to be help manipulate the contents of a text input field. It keeps track of the logical lines of text (i.e., lines separated by user-entered newlines) and the current cursor position. Several functions are defined in this module to navigate and edit the TextZipper from the cursor position. TextZippers can be converted into DisplayLines, which describe how the contents of the zipper will be displayed when wrapped to fit within a container of a certain width. It also provides some convenience facilities for converting interactions with the rendered DisplayLines back into manipulations of the underlying TextZipper.

A zipper of the logical text input contents (the "document"). The lines before the line containing the cursor are stored in reverse order. The cursor is logically between the "before" and "after" text. A "logical" line of input is a line of input up until a user-entered newline character (as compared to a "display" line, which is wrapped to fit within a given viewport width).

Map a replacement function over the characters in a TextZipper

Default vty event handler for text inputs