The author: "I think I prefer length over len, because then I'll use len as
the variable name". One arm in check.ml, one row in the table beside it, and
every (len x) in lib, test, examples, vendor, spike, docs, web, emacs,
plan.org and NEXT.md rewritten.
Shadowing and builtin/ had already taken most of the sting out: a (defn len
...) was legal and won in its own file, and builtin/len reached past it. What
was left is that len was still a builtin — the defn earned a warning, and a
wrapper had to say builtin/ at every inner call. Now there is nothing under
the short name: len is an ordinary identifier in every position, which is
what (let [len (length xs)] ...) wants.
length takes over as shadowing's worked example rather than the feature
losing one. shadow-builtin.flan, builtin-qualified.flan, pkgs/shadowed and the
builtin/ rows in test_flan move to it and go on testing shadowing.
A call to a len nothing defines is answered where an unknown function is,
after every table and after the shadowing guard, so a program with its own len
never reaches it. The sentence is said rather than guessed at — len and length
are three edits apart and the did-you-mean's net is one — and the call is
written back out through spell_arg, as-slice's spelling lifted out of it and
now shared, so what is printed compiles.
sand.flan:33 still calls the old name and is the author's to change; until it
does, test_acceptance and test_session abort there. Both were run green
against a copy with that one line changed. FIX.org says so.
The !-means-mutates convention distinguished nothing — there is no
immutable counterpart to contrast with — so every mutating name drops
the mark: sort, sort-by, sort-bytes, swap, reverse, append, append-i64,
append-f64, encode-rune, split-next, map-remove, map-next, and the test
helpers beside them. Two could not simply shed it: map! is map-in-place,
because map is the into transform's word and means the non-mutating
thing; put! is put-at, because put is the Map builtin. The ?-means-asks
convention stays. Dated records keep the old spellings; watch.clj's
reset-spies! and the other Clojure names are not ours to rename.
swap!, reverse!, sort!, sort-by!, index-of, min-of, max-of, map!,
reduce and filter, each written once over $t. Every call site in the
corpus moves with them.
min-of and max-of are not min and max because min and max are builtins
over two or more numbers and nothing shadows a builtin. These reduce a
slice, which is a different operation at a different arity.
sort-bytes! did not collapse into sort!, and the reason is the point of
the predicates: a [u8] is not ordered? and cannot be, because < is an
instruction and comparing two slices lexicographically is a loop. It is
sort-by! with bytes<? written in, one line, keeping its name and its
stability note. sum-i32/sum-f32 and append-i64!/append-f64! stay for the
reasons the spike gave.
Not what the notes predicted: none of the ten collapses on a signature
change alone. filter and reduce need copyable? because the checker
demands it - reduce's accumulator at (Vec i32) is a double move - and
the rest declare it because a slice of owning elements would have them
duplicating headers.
