diff --git a/raptor/src/lib.rs b/raptor/src/lib.rs index 85ad4628e..999218169 100644 --- a/raptor/src/lib.rs +++ b/raptor/src/lib.rs @@ -4,6 +4,7 @@ pub mod rank; pub mod metadata; pub mod vec_read_only; pub mod automaton; +pub mod tokenizer; pub use self::metadata::{Metadata, MetadataBuilder}; pub use self::rank::RankedStream; diff --git a/raptor/src/tokenizer/mod.rs b/raptor/src/tokenizer/mod.rs new file mode 100644 index 000000000..23bb118a4 --- /dev/null +++ b/raptor/src/tokenizer/mod.rs @@ -0,0 +1,137 @@ +use std::mem; +use self::Separator::*; + +pub struct Tokenizer<'a> { + inner: &'a str, +} + +impl<'a> Tokenizer<'a> { + pub fn new(string: &str) -> Tokenizer { + Tokenizer { inner: string } + } + + pub fn iter(&self) -> Tokens { + Tokens::new(self.inner) + } +} + +pub struct Tokens<'a> { + index: usize, + inner: &'a str, +} + +impl<'a> Tokens<'a> { + fn new(string: &str) -> Tokens { + Tokens { + index: 0, + inner: string.trim_matches(&[' ', '.', ';', ',', '!', '?', '-'][..]), + } + } +} + +#[derive(Debug, Clone, Copy)] +enum Separator { + Short, + Long, +} + +impl Separator { + fn add(self, add: Separator) -> Separator { + match (self, add) { + (_, Long) => Long, + (Short, Short) => Short, + (Long, Short) => Long, + } + } + + fn to_usize(self) -> usize { + match self { + Short => 1, + Long => 8, + } + } +} + +impl<'a> Iterator for Tokens<'a> { + type Item = (usize, &'a str); + + fn next(&mut self) -> Option { + let mut start_word = None; + let mut distance = None; + + for (i, c) in self.inner.char_indices() { + let separator = match c { + '.' | ';' | ',' | '!' | '?' | '-' => Some(Long), + ' ' => Some(Short), + _ => None, + }; + + match separator { + Some(dist) => { + if let Some(start_word) = start_word { + let (word, tail) = self.inner.split_at(i); + + self.inner = tail; + self.index += distance.map(Separator::to_usize).unwrap_or(0); + + let word = &word[start_word..]; + return Some((self.index, word)) + } + distance = Some(distance.map(|s| s.add(dist)).unwrap_or(dist)); + }, + None => { start_word.get_or_insert(i); }, + } + } + + if let Some(start_word) = start_word { + let word = mem::replace(&mut self.inner, ""); + self.index += distance.map(Separator::to_usize).unwrap_or(0); + + let word = &word[start_word..]; + return Some((self.index, word)) + } + + None + } +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn easy() { + let tokenizer = Tokenizer::new("salut"); + let mut tokens = tokenizer.iter(); + + assert_eq!(tokens.next(), Some((0, "salut"))); + assert_eq!(tokens.next(), None); + + let tokenizer = Tokenizer::new("yo "); + let mut tokens = tokenizer.iter(); + + assert_eq!(tokens.next(), Some((0, "yo"))); + assert_eq!(tokens.next(), None); + } + + #[test] + fn hard() { + let tokenizer = Tokenizer::new(" .? yo lolo. aïe"); + let mut tokens = tokenizer.iter(); + + assert_eq!(tokens.next(), Some((0, "yo"))); + assert_eq!(tokens.next(), Some((1, "lolo"))); + assert_eq!(tokens.next(), Some((9, "aïe"))); + assert_eq!(tokens.next(), None); + + let tokenizer = Tokenizer::new("yo ! lolo ? wtf - lol . aïe ,"); + let mut tokens = tokenizer.iter(); + + assert_eq!(tokens.next(), Some((0, "yo"))); + assert_eq!(tokens.next(), Some((8, "lolo"))); + assert_eq!(tokens.next(), Some((16, "wtf"))); + assert_eq!(tokens.next(), Some((24, "lol"))); + assert_eq!(tokens.next(), Some((32, "aïe"))); + assert_eq!(tokens.next(), None); + } +}