Soundex — a dart

THE TECHNIQUE keep first letter · map by articulation · drop vowels & dups

Keep the first letter as a letter. Map each following consonant to a digit by where the mouth makes it (labials→1, gutturals/sibilants→2, dentals→3, l→4, nasals→5, r→6). Drop vowels. Collapse runs of the same digit. h and w are transparent — they don’t break a collapse. Pad or cut to one letter + three digits. live demo

B F P V → 1 C G J K Q S X Z → 2 D T → 3 L → 4 M N → 5 R → 6 A E I O U (Y) → dropped (they SEPARATE equal digits) H W → transparent (they do NOT)

■ first letter (kept) ■ coded digit ■ vowel / dropped ■ h,w transparent ■ collapsed / overflow

A cabinet of names — one per line. Encode them, and the ones that sound alike land in the same drawer:

Or type any single name and watch the per-character classification live — this is pure string work, letter by letter:

name = → code —

HISTORY & CREDIT credit where it is due

People meet Soundex inside a database (SOUNDEX() ships in SQL Server, Oracle, PostgreSQL’s fuzzystrmatch) and assume it’s a ~~1970s computing invention~~. It is not — it predates the electronic computer by a generation. cited

1918 · Robert C. Russell files the first patent (US 1,261,167) — a hand method for filing names by sound on index cards.
1922 · Robert C. Russell & Margaret King Odell extend it in a second patent (US 1,435,663). The two of them are the real inventors.
1927 · Rand Kardex Bureau, Inc. registers the SOUNDEX trademark.
1930s · a variant, American Soundex, is used by the U.S. WPA / National Archives to index the 1880–1920 censuses by surname — the use that made it famous.
today · NARA still publishes the canonical coding rules (General Information Leaflet 55).

Commonly mis-credited: Soundex is often attributed vaguely to “the Census Bureau” or to whatever database vendor a programmer met it through — erasing Russell and Odell. The inventors are named on the patents; say their names. cited

What’s open / debated: the exact treatment of Y and of vowel-separated repeats varies between implementations, which is why SOUNDEX() in two databases can disagree on a hard name. Soundex is also known to be weak — it’s Anglo-centric and coarse — which is why NYSIIS (1970), Daitch–Mokotoff (1985) and Metaphone (1990) were built to replace it. open

RECOMMEND FOR I-13 what the galaxy should learn

Every step above is string work: read a character, ask “what letter is this”, branch on its class. I-13 has no strings and no chars — its one literal type, Constant, is f64 only. So this technique is not hard in I-13; it is unspeakable. I proved it on the real compiler — the source that just wants to name “Robert” will not even parse:

$ i13 check s.i13 # source: I s <- "Robert" s.i13:1:8 E0001 unexpected character `"` s.i13:1:15 E0001 unexpected character `"` EXIT=1 — the double-quote is not in the alphabet; there is no string token $ i13 run n.i13 # source: I a <- 66 / I b <- a * 2 RUN OK · 6 step(s) · peak stack 2 a = 66 b = 132 — numbers are all it will hold

Recommend (honest, and NOT the cheap fix): to reach text at all, I-13 would need a genuine string / char type — a new Constant variant carrying bytes, a lexer token for quotes, and at minimum a per-character classify and index operation. That is a type-system change, not a spare BinOp discriminant. Earlier darts could patch a missing operator (%, >>) for zero new alphabet symbols; this one cannot — text needs a new kind of value, and the whole point of the 13-symbol census is that new kinds of value are exactly what it excludes.
So the real recommendation is a scope ruling, not a bug fix: decide whether I-13 is a numeric-scalar language on purpose. If yes, string algorithms like Soundex are permanently and honestly out of range — and that’s fine; the counted alphabet earned its purity. If text is ever in scope, it’s a deliberate second literal type, paid for in full, not smuggled in as an operator.
Tradeoff (honest): a string type buys a whole universe (parsing, hashing, phonetics) but breaks the cleanest thing about I-13 — that a Constant is one f64 and the alphabet was counted, not designed. Soundex is the clarifying case: not a lack to fill, but a border to name.