Crates.io | ptb-reader |
lib.rs | ptb-reader |
version | 0.9.1 |
source | src |
created_at | 2017-03-06 20:22:27.410583 |
updated_at | 2017-08-02 14:52:22.704919 |
description | Simple parsing of the merged Penn Treebank format. |
homepage | https://github.com/sjmielke/ptb-reader-rust |
repository | https://github.com/sjmielke/ptb-reader-rust |
max_upload_size | |
id | 8860 |
size | 27,078 |
Natural language processing work on syntax starts with being able to read standard corpora, such as the Penn Treebank. This crate is able to parse the merged (i.e. syntactic structure and POS tags) files of the free sample and the full PTB Wall Street Journal section.
The output of the parser is a Vec<PTBTree>
, PTBTree
being defined by:
pub enum PTBTree {
InnerNode {
label: String,
children: Vec<PTBTree>
},
TerminalNode {
label: String
}
}
PTBTree
implements the Display
trait, showing the PTB-bracketed notation. It also supports From
/Into
String
, yielding the front of the tree (i.e., the concatenation of all terminals).
Parse the whole PTB sample:
let all_trees: Vec<PTBTree> = ptb_reader::parse_ptb_dir("/home/sjm/documents/Uni/penn-treebank-sample/treebank/combined/");
Parse and work with an individual tree:
let s: String = "((S (NNP John) (VP (VBD saw) (NNP Mary))))";
let t: PTBTree =
PTBTree::InnerNode{ label: "S".to_string(), children: vec![
PTBTree::InnerNode{ label: "NNP".to_string(), children: vec![
PTBTree::TerminalNode{ label: "John".to_string() }
] },
PTBTree::InnerNode{ label: "VP".to_string(), children: vec![
PTBTree::InnerNode{ label: "VBD".to_string(), children: vec![
PTBTree::TerminalNode{ label: "saw".to_string() }
] },
PTBTree::InnerNode{ label: "NNP".to_string(), children: vec![
PTBTree::TerminalNode{ label: "Mary".to_string() }
] }
] }
] }
;
assert_eq!(parse_ptbtree(s).unwrap(), t);
assert_eq!(t.render(), s);
assert_eq!(t.front(), "John saw Mary");
Strip predicate-argument annotations:
let s: &str = "((S (NNP John) (VP (VBD saw) (NNP Mary) )))";
let s_pred: &str = "((S (NNP-SBJ John) (VP (NP *T*-1) (VBD saw) (NNP Mary) (-NONE- nada))))";
let mut t = parse_ptbtree(s_pred).unwrap();
t.strip_all_predicate_annotations();
assert_eq!(t, parse_ptbtree(s).unwrap())