Datasets:
File size: 1,097 Bytes
c62beea | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 | use vstd::prelude::*;
fn main() {}
verus!{
spec fn f1_is_lower_case(c: u8) -> bool {
c >= 97 && c <= 122
}
spec fn f1_is_upper_case(c: u8) -> bool {
c >= 65 && c <= 90
}
spec fn f1_count_uppercase_recursively(seq: Seq<u8>) -> int
decreases seq.len(),
{
if seq.len() == 0 {
0
} else {
f1_count_uppercase_recursively(seq.drop_last()) + if f1_is_upper_case(seq.last()) {
1 as int
} else {
0 as int
}
}
}
fn f1_count_uppercase(text: &[u8]) -> (count: u64)
{
let mut index = 0;
let mut count = 0;
while index < text.len()
{
if (text[index] >= 65 && text[index] <= 90) {
count += 1;
}
index += 1;
}
count
}
spec fn step1(__hp0: Seq<u8>, outp: u64) -> bool {
(0 <= outp <= __hp0.len())
&& (f1_count_uppercase_recursively(__hp0) == outp)
}
fn chain_driver(text: &[u8]) -> (r_final: u64)
ensures
step1(text@, r_final),
{
let x1 = f1_count_uppercase(text);
proof {
assert(step1(text@, x1));
}
x1
}
} // verus!
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