Use checked_sub

Recently we "if" guarded subtraction manually using `> 0`, we can better
convey the meaning by using `checked_sub` and pattern match on the
option.

Refactor only, no logic changes.
This commit is contained in:
Tobin C. Harding 2023-08-29 09:01:25 +10:00
parent c06c9beb01
commit de95bf52cb
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GPG Key ID: 40BF9E4C269D6607
1 changed files with 21 additions and 17 deletions

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@ -68,27 +68,31 @@ fn fmt_debug(w: &Witness, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error>
f.write_str("witnesses: [")?; f.write_str("witnesses: [")?;
let instructions = w.iter(); let instructions = w.iter();
if instructions.len() > 0 { match instructions.len().checked_sub(1) {
let last_instruction = instructions.len() - 1; Some(last_instruction) => {
for (i, instruction) in instructions.enumerate() { for (i, instruction) in instructions.enumerate() {
let bytes = instruction.iter(); let bytes = instruction.iter();
if bytes.len() > 0 { match bytes.len().checked_sub(1) {
let last_byte = bytes.len() - 1; Some(last_byte) => {
f.write_str("[")?; f.write_str("[")?;
for (j, byte) in bytes.enumerate() { for (j, byte) in bytes.enumerate() {
write!(f, "{:#04x}", byte)?; write!(f, "{:#04x}", byte)?;
f.write_str(comma_or_close(j, last_byte))?; f.write_str(comma_or_close(j, last_byte))?;
} }
} else { }
None => {
// This is possible because the varint is not part of the instruction (see Iter). // This is possible because the varint is not part of the instruction (see Iter).
write!(f, "[]")?; write!(f, "[]")?;
} }
}
f.write_str(comma_or_close(i, last_instruction))?; f.write_str(comma_or_close(i, last_instruction))?;
} }
} else { }
None => {
// Witnesses can be empty because the 0x00 var int is not stored in content. // Witnesses can be empty because the 0x00 var int is not stored in content.
write!(f, "]")?; write!(f, "]")?;
} }
}
f.write_str(" }") f.write_str(" }")
} }