57 lines
1.4 KiB
Rust
57 lines
1.4 KiB
Rust
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//! # Lexer
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mod characters {
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use std::collections::HashSet;
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use std::iter::FromIterator;
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pub type CharSet = HashSet<char>;
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pub fn ascii_letters() -> CharSet {
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let letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".chars();
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return CharSet::from_iter(letters);
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}
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pub fn ascii_digits() -> CharSet {
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let digits = "1234567890".chars();
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return CharSet::from_iter(digits);
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}
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pub fn identifier_initials() -> CharSet {
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let letters = ascii_letters();
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let extras = CharSet::from_iter("!$%&*/:<=>?~_^".chars());
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let mut initials = CharSet::new();
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initials.extend(letters.iter());
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initials.extend(extras.iter());
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return initials;
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}
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pub fn identifier_subsequents() -> CharSet {
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let initials = identifier_initials();
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let digits = ascii_digits();
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let extras = CharSet::from_iter(".+-".chars());
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let mut subsequents = CharSet::new();
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subsequents.extend(initials.iter());
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subsequents.extend(digits.iter());
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subsequents.extend(extras.iter());
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return subsequents;
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}
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}
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enum Kind {
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LeftParen,
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RightParen,
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Identifier,
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}
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struct Token {
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kind: Kind,
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value: String,
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}
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pub fn hello(person: &str) {
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println!("Hello, {}!", person);
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for (idx, c) in person.char_indices() {
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println!(" {}, {} -> {}", c, idx, characters::ascii_letters().contains(&c));
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}
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}
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