Documentation

(i :.. n) represents a span of text between index i and index i+n.

The type of indices p is expected to be an instance of Amor.

The length n in an interval (i :.. n) may be zero.

The elements of the interval can be thought of as indexing the interstices between characters. A span of length zero is a single interstice between two characters, where some chunk of text may be inserted.

Example: drawing of 1 :.. 2 in "abcde".

 a b c d e
0 1 2 3 4 5
  ^b+c+ length = 2
  ^
  ^ start = 1

Does the interval have length zero?

A minimalistic representation of text replacements.

A replacement Replace i n m is given by a start location i, the length n of the interval to replace (source) and the length m of its replacement (target). This representation does not keep track of the actual data being inserted.

This may overapproximate the underlying text replacement, with intervals being wider than necessary. For example, the transformation from "abc" to "ac" could be represented by mkReplace 1 1 0 (replace "b" with "" at location 1), and also by mkReplace 0 2 1 (replace "ab" with "a" at location 0).

source   abc   abc
     -    b    ab
     +         a
target   a c   a c

Insertions are replacements with source intervals of length zero. Deletions are replacements with target intervals of length zero.