Phonetic encoders

Hand-vectorised implementations of the standard phonetic codecs — Soundex, Metaphone (two variants), Double Metaphone (two variants), NYSIIS, Match Rating Approach (MRA), Caverphone 2, Cologne Phonetic, Daitch-Mokotoff Soundex, and Beider-Morse Phonetic Matching. Bit-for-bit agreement with the reference implementation in each case; the variant kwarg picks which spec where multiple ports diverge.

Encoder / matcher pairs

Each encoder family ships in two flavours: an encode(name) that returns the phonetic key as a string, and an equal(a, b) (or compare(a, b) for MRA) that returns whether two names encode to the same key, with the engine avoiding the allocation. Use the second when you only care about the match.

Variant-selecting enums

MetaphoneVariant

from stride_align import metaphone, MetaphoneVariant

metaphone("school", MetaphoneVariant.PHILIPS)    # 'SXKL'  (Apache Commons branch)
metaphone("school", MetaphoneVariant.JELLYFISH)  # 'SXKL'  (jellyfish branch)
metaphone("rough",  MetaphoneVariant.PHILIPS)    # 'RF'    (Philips: GH silent)
metaphone("rough",  MetaphoneVariant.JELLYFISH)  # 'RFKH'  (jellyfish: GH → KH at end)

• PHILIPS (default) — Lawrence Philips' 1990 spec, matches Apache Commons Codec.
• JELLYFISH — matches the jellyfish PyPI package (diverges on SCH and word-final GH).

DoubleMetaphoneVariant

from stride_align import double_metaphone, DoubleMetaphoneVariant

double_metaphone("Hugh", DoubleMetaphoneVariant.COMMONS)  # ('H',  '')
double_metaphone("Hugh", DoubleMetaphoneVariant.PYTHON)   # ('HH', '')  — bug-for-bug

• COMMONS (default) — Apache Commons Codec / doublemetaphone PyPI package. Correct per the Philips spec.
• PYTHON — bug-for-bug compatibility with the metaphone PyPI package, which has a missing else in its GH branch that lets the previous character's emission leak.

Examples

import stride_align as sa

sa.soundex("Robert")             # 'R163'
sa.soundex_equal("Robert", "Rupert")  # True

sa.nysiis("Knuth")               # 'NAT'
sa.metaphone("Schwarzenegger")   # 'SWRSNKR'
sa.caverphone("Catherine")       # 'KTRN111111'
sa.cologne_phonetic("Müller")    # '657'   (Latin-1 / Unicode-aware)

# Daitch-Mokotoff and Beider-Morse return MULTIPLE codes for a name
# (one per pronunciation branch). Compare via set intersection:
codes_a = set(sa.daitch_mokotoff("Goldberg").split())
codes_b = set(sa.daitch_mokotoff("Goldburg").split())
match = bool(codes_a & codes_b)

# Beider-Morse with rule-family selection
from stride_align import beider_morse, BmpmRuleType
codes = beider_morse("Müller", rule_type=BmpmRuleType.GENERIC)

Unicode behaviour

Soundex and NYSIIS are pure-ASCII algorithms by definition; non-ASCII codepoints are skipped. Metaphone, Double Metaphone, Caverphone, MRA, and Daitch-Mokotoff follow their reference implementations on the ASCII subset.

The encoders that were designed for non-ASCII text — Cologne Phonetic (German) and Beider-Morse (Jewish names, many rule families) — accept the full Unicode codepoint range through the UCS-1 / UCS-2 / UCS-4 zero-copy bridge and handle diacritics natively. No .encode('utf-8') round-trip needed.

When to use which