Crate nsv 

NSV (Newline-Separated Values) format implementation for Rust

Fast implementation using memchr, with optional parallel parsing via rayon. See https://nsv-format.org for the specification.

Parallel Parsing Strategy

For files larger than 64KB, we use a chunked parallel approach:

1. Pick N evenly-spaced byte positions (one per CPU core)
2. For each, scan forward to the nearest \n\n row boundary — O(avg_row_len)
3. Each worker independently parses its chunk (boundary scan + cell split + unescape)

This works because literal 0x0A bytes in NSV are always structural (never escaped), so row alignment recovery from any byte position is a trivial forward scan. The sequential phase is O(N), not O(input_len) — all real work is parallel.

For smaller files, we use a sequential fast path to avoid thread overhead.

Modules

util

Utility functions for NSV structural operations.

Structs

Reader

Streaming NSV reader. Yields one complete row of byte vectors at a time.

Warning

A single warning found during validation.

Writer

Streaming NSV writer. Wraps any W: Write and writes one row at a time.

Enums

WarningKind

Constants

VERSION

Functions

check

Report edge cases in raw NSV input without altering parsing behavior.

decode

Decode an NSV string into a seqseq.

decode_bytes

Decode raw bytes into a seqseq of byte slices. No encoding assumption — works with any ASCII-compatible encoding.

decode_bytes_projected

Decode only the specified columns from raw bytes.

encode

Encode a seqseq into an NSV string.

encode_bytes

Encode a seqseq of byte vectors into raw NSV bytes.

escape

Escape a single NSV cell.

escape_bytes

Escape a single raw cell (byte-level).

unescape

Unescape a single NSV cell.

unescape_bytes

Unescape a single raw cell (byte-level).