Brolib-sml

Introduction

Standard ML port of this rope implementation.

This particular rope uses the balancing scheme described in the Purely Functional 1-2 Brother Trees paper authored by Ralph Hinze. It tries to keep the number of nodes to a minimum by joining the strings in adjacent leaf nodes, if joining would not be too expensive.

Usage

The two files are rope.sml and tiny_rope.sml.

rope.sml contains a rope that tracks line metadata (which has a small performance and memory penalty). This is useful if you have line-based operations in mind.

tiny_rope.sml doesn't track line metadata, and is useful when line-queries aren't needed.

Except for those line-based operations marked below, all functions are the same between the two.

Examples

Initialise

val rope = Rope.fromString "hello, world!"

It's best to use a string with a length less than or equal to 1024 for performance reasons. (The point of a rope is to represent a large string using a binary tree that contains smaller pieces.)

Convert to string

val str = Rope.toString rope

This is a function that is better to avoid.

Insert

Rope.insert(0, "hello, world!")