merge.interval_index: Merge Two Interval Indices

In Immutables: Fast and Functional Data Structures

Merge Two Interval Indices

Description

Returns a new interval_index containing every entry from both inputs, preserving start-position order. On tied start positions, x's entries precede y's (left-biased FIFO).

Usage

## S3 method for class 'interval_index'
merge(x, y, ...)

Arguments

x	An interval_index.
y	An interval_index.
...	Unused.

Details

The merge runs in O(m + n) via a zipper-style traversal on interval starts, with a fast path to O(log(min(m, n))) when the start ranges are disjoint.

Both indices must share the same endpoint type and the same bounds convention (e.g. "[)" half-open vs. "[]" closed), and the same monoid set. Mismatches error.

The reserved monoids .ivx_min_end / .ivx_max_end recompute automatically on the merged tree, so min_endpoint() / max_endpoint() and interval-relation queries work immediately on the result.

Both inputs are left unmodified.

Value

A new interval_index of size length(x) + length(y).

Examples

a <- interval_index("A1", "A2", start = c(1, 5), end = c(4, 8))
b <- interval_index("B1", "B2", start = c(3, 7), end = c(6, 10))
m <- merge(a, b)
as.list(m)

Immutables documentation built on April 29, 2026, 1:06 a.m.