Module text 

Shared text position types and helpers used by the buffer.

This module is intentionally “rope-agnostic” (it operates on indices and provides conversions given line-start information), so it can be reused whether the backing store is a Rope, a gap buffer, etc.

When used with ropey::Rope, you typically pair these helpers with:

• Rope::len_chars()
• Rope::line_to_char(line)
• Rope::char_to_line(char_idx)
• Rope::line(line).len_chars() (includes newline if present)

Structs

CharIdx

A 0-based character index (Unicode scalar value index).

CharRange

A half-open character range: [start, end).

ColIdx

A 0-based column index in characters within a line.

GoalCol

A small helper for “preferred column” behavior (vim-like vertical motion).

LineCol

A (line, column) location in the buffer.

LineIdx

A 0-based line index.

Functions

apply_goal_col

Updates (actual_col, goal_col) when moving vertically.

char_to_line_col

Computes a (line, col) for a given char_idx using a provided line_to_char function.

clamp_char

Clamps a char index into [0, len_chars].

clamp_col_to_line

Given a line length in chars, clamp a goal column to the line.

clamp_cursor_to_line_editable

Clamp a cursor char index into the editable bounds of its line.

clamp_range

Normalizes and clamps a range into [0, len_chars].

line_col_to_char

Computes a char index for a given (line, col) using a provided line_to_char function and a line_len_chars function.

line_editable_bounds

Computes the common “cursor line start” and “cursor line end” bounds.

line_len_without_newline

Computes a safe “visual” line length in chars, excluding a trailing \n if present (common for ropey lines).

move_char_clamped

Compute the next/prev character index with clamping.

ordered_pair

Returns (min, max) ordering of two char indices.