18 lines
679 B
Markdown
18 lines
679 B
Markdown
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# Processing
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## Redundant requires
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Sometimes the code will look like it duplicates matching logic. For example:
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```rust
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fn process_comment(proc: &mut Proc) -> () {
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proc.matches("<!--").require_reason("comment").skip();
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proc.while_not_matches("-->").skip();
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proc.matches("-->").require_reason("comment end").skip();
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}
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```
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At first glance, it might appear that the second call `while_not_matches` makes it redundant to require it again immediately afterwards. However, it's possible that the `while_not_matches` actually stops for some other reason, such as reaching EOF. Even if it's guaranteed, it's still nice to have a declared invariant, like an assertion statement.
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