Brummel
9cf0e3e81c
Eleven binary builtins (+ - * / % == != < <= > >=) render as lhs op rhs when called with two args (tail-flagged keeps prefix). Standard Rust-aligned 4-level precedence table elides parens. not(x) renders as !x. Long /// doc strings wrap at 80 cols on word boundaries. bench_list_sum: 'if ==(n, 0)' becomes 'if n == 0', '+(acc, h)' becomes 'acc + h', tail keyword still visible on tail calls. 19 new unit tests (47 total). 4 snapshots (3 re-rendered + 1 new bench fixture). Public API unchanged.
42 lines
871 B
Plaintext
42 lines
871 B
Plaintext
// module bench_list_sum
|
|
|
|
data IntList = INil | ICons(Int, IntList)
|
|
|
|
/// Tail-recursive list builder. Result = accumulator-prepended list.
|
|
fn cons_n_acc(n: Int, acc: IntList) -> IntList {
|
|
if n == 0 {
|
|
acc
|
|
} else {
|
|
tail cons_n_acc(n - 1, ICons(n - 1, acc))
|
|
}
|
|
}
|
|
|
|
/// Build [0, 1, ..., n-1] :: IntList. Order doesn't matter for sum.
|
|
fn cons_n(n: Int) -> IntList {
|
|
cons_n_acc(n, INil)
|
|
}
|
|
|
|
/// Tail-recursive sum.
|
|
fn sum_acc(xs: IntList, acc: Int) -> Int {
|
|
match xs {
|
|
INil => acc,
|
|
ICons(h, t) => tail sum_acc(t, acc + h)
|
|
}
|
|
}
|
|
|
|
/// Sum every element. Calls sum_acc with seed 0.
|
|
fn sum_list(xs: IntList) -> Int {
|
|
sum_acc(xs, 0)
|
|
}
|
|
|
|
/// Build a list of length n, sum it, print the sum.
|
|
fn run_one(n: Int) -> Unit with IO {
|
|
do io/print_int(sum_list(cons_n(n)))
|
|
}
|
|
|
|
fn main() -> Unit with IO {
|
|
run_one(100000);
|
|
run_one(1000000);
|
|
run_one(3000000)
|
|
}
|