40 lines
1.2 KiB
Rust
40 lines
1.2 KiB
Rust
//! Utility functions.
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use std::path::Path;
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use std::fs::File;
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use std::io::{Result, Read};
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/// Read an entire file into a string.
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pub fn read_to_string<P: AsRef<Path>>(path: P) -> Result<String> {
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let mut file = File::open(path)?;
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let mut buffer = String::new();
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file.read_to_string(&mut buffer)?;
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Ok(buffer)
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}
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/// Look for a directive in a comment string.
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/// The directive is of the form "foo:" and should follow the leading `;` in the comment:
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///
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/// ; dominates: ebb3 ebb4
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///
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/// Return the comment text following the directive.
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pub fn match_directive<'a>(comment: &'a str, directive: &str) -> Option<&'a str> {
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assert!(directive.ends_with(':'),
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"Directive must include trailing colon");
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let text = comment.trim_left_matches(';').trim_left();
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if text.starts_with(directive) {
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Some(text[directive.len()..].trim())
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} else {
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None
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}
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}
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#[test]
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fn test_match_directive() {
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assert_eq!(match_directive("; foo: bar ", "foo:"), Some("bar"));
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assert_eq!(match_directive(" foo:bar", "foo:"), Some("bar"));
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assert_eq!(match_directive("foo:bar", "foo:"), Some("bar"));
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assert_eq!(match_directive(";x foo: bar", "foo:"), None);
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assert_eq!(match_directive(";;; foo: bar", "foo:"), Some("bar"));
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}
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