diff --git a/Cargo.toml b/Cargo.toml
index b12e04f41..341c58db0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,3 +14,5 @@ rand = "0.3.13"
 atomicwrites = "0.0.14"
 tempfile = "2.0.0"
 rustc-serialize = "0.3.16"
+combine = "1.2.0"
+tempdir = "0.3.4"
diff --git a/src/core/directory.rs b/src/core/directory.rs
index f2962389f..5dafd14dd 100644
--- a/src/core/directory.rs
+++ b/src/core/directory.rs
@@ -1,4 +1,4 @@
-use std::path::PathBuf;
+use std::path::{PathBuf, Path};
 use std::collections::HashMap;
 use std::collections::hash_map::Entry;
 use std::fs::File;
@@ -17,6 +17,7 @@ use rand::{thread_rng, Rng};
 use fst::raw::MmapReadOnly;
 use rustc_serialize::json;
 use atomicwrites;
+use tempdir::TempDir;
 
 #[derive(Clone, Debug)]
 pub struct SegmentId(pub String);
@@ -43,12 +44,6 @@ impl DirectoryMeta {
     }
 }
 
-#[derive(Clone)]
-pub struct Directory {
-    index_path: PathBuf,
-    mmap_cache: Arc<Mutex<HashMap<PathBuf, MmapReadOnly>>>,
-    metas: DirectoryMeta,
-}
 
 impl fmt::Debug for Directory {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
@@ -79,6 +74,15 @@ fn sync_file(filepath: &PathBuf) -> Result<()> {
     }
 }
 
+
+#[derive(Clone)]
+pub struct Directory {
+    index_path: PathBuf,
+    mmap_cache: Arc<Mutex<HashMap<PathBuf, MmapReadOnly>>>,
+    metas: DirectoryMeta,
+    _temp_directory: Option<Arc<TempDir>>,
+}
+
 impl Directory {
 
     // TODO find a rusty way to hide that, while keeping
@@ -89,16 +93,42 @@ impl Directory {
     }
 
     pub fn from(filepath: &str) -> Result<Directory> {
-        // TODO error management
         let mut directory = Directory {
             index_path: PathBuf::from(filepath),
             mmap_cache: Arc::new(Mutex::new(HashMap::new())),
-            metas: DirectoryMeta::new()
+            metas: DirectoryMeta::new(),
+            _temp_directory: None,
         };
         try!(directory.load_metas()); //< does the directory already exists?
         Ok(directory)
     }
 
+    fn create_tempdir() -> Result<TempDir> {
+        let tempdir_res = TempDir::new("index");
+        match tempdir_res {
+            Ok(tempdir) => Ok(tempdir),
+            Err(_) => Err(Error::FileNotFound(String::from("Could not create temp directory")))
+        }
+    }
+
+    pub fn from_tempdir() -> Result<Directory> {
+        let tempdir = try!(Directory::create_tempdir());
+        let tempdir_path: PathBuf;
+        {
+            tempdir_path = PathBuf::from(tempdir.path());
+        };
+        let tempdir_arc = Arc::new(tempdir);
+        let mut directory = Directory {
+            index_path: PathBuf::from(tempdir_path),
+            mmap_cache: Arc::new(Mutex::new(HashMap::new())),
+            metas: DirectoryMeta::new(),
+            _temp_directory: Some(tempdir_arc)
+        };
+        //< does the directory already exists?
+        try!(directory.load_metas());
+        Ok(directory)
+    }
+
     pub fn load_metas(&mut self,) -> Result<()> {
         // TODO load segment info
         Ok(())
diff --git a/src/core/mod.rs b/src/core/mod.rs
index 59260d8c1..6aca6ad90 100644
--- a/src/core/mod.rs
+++ b/src/core/mod.rs
@@ -1,4 +1,4 @@
-
+pub mod query;
 pub mod postings;
 pub mod global;
 pub mod schema;
diff --git a/src/core/query.rs b/src/core/query.rs
new file mode 100644
index 000000000..b8972fd7a
--- /dev/null
+++ b/src/core/query.rs
@@ -0,0 +1,61 @@
+use combine;
+use combine::{between, char, letter, spaces, space, many1, parser, sep_by1, Parser, ParseError, ParserExt, combinator};
+use combine::primitives::{State, Stream, ParseResult};
+
+#[derive(Debug, PartialEq)]
+pub struct Term(pub String, pub String);
+
+
+#[derive(Debug, PartialEq)]
+pub enum BoolExpr {
+    AlwaysTrue,
+    Conjunction(Vec<Term>),
+}
+
+
+
+pub fn grammar<I>(input: State<I>) -> ParseResult<BoolExpr, I>
+    where I: Stream<Item=char>
+{
+    let make_term = || {
+        let term_field: combinator::Many1<String, _> = many1(letter());
+        let term_value: combinator::Many1<String, _>  = many1(letter());
+        (term_field, char(':'), term_value).map(|t| Term(t.0.clone(), t.2.clone()))
+    };
+
+
+    // let term_seqs = (make_term(), space(), parser(grammar::<I>),).map(|t| BoolExpr::AlwaysTrue);
+    sep_by1(make_term(), space())
+        .map(BoolExpr::Conjunction)
+        .parse_state(input)
+    // make_term().or(term_seqs).parse_state(input)
+    //make_term()
+
+    //
+    // let word = many1(letter());
+    //
+    // //Creates a parser which parses a char and skips any trailing whitespace
+    // let lex_char = |c| char(c).skip(spaces());
+    //
+    // let comma_list = sep_by(parser(expr::<I>), lex_char(','));
+    // let array = between(lex_char('['), lex_char(']'), comma_list);
+    //
+    // //We can use tuples to run several parsers in sequence
+    // //The resulting type is a tuple containing each parsers output
+    // let pair = (lex_char('('),
+    //             parser(expr::<I>),
+    //             lex_char(','),
+    //             parser(expr::<I>),
+    //             lex_char(')'))
+    //                .map(|t| Expr::Pair(Box::new(t.1), Box::new(t.3)));
+    //
+    // word.map(Expr::Id)
+    //     .or(array.map(Expr::Array))
+    //     .or(pair)
+    //     .skip(spaces())
+    //     .parse_state(input)
+}
+
+pub fn parse_query(query_str: &str) -> Result<(BoolExpr, &str), ParseError<&str>> {
+    parser(grammar).parse(query_str)
+}
diff --git a/src/lib.rs b/src/lib.rs
index d9bb16e2d..f53e46ae6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -8,7 +8,8 @@ extern crate memmap;
 extern crate rand;
 extern crate regex;
 extern crate rustc_serialize;
+extern crate combine;
 extern crate atomicwrites;
-
+extern crate tempdir;
 
 pub mod core;
diff --git a/tests/core.rs b/tests/core.rs
index 964ea72fa..8ce0b7fb5 100644
--- a/tests/core.rs
+++ b/tests/core.rs
@@ -20,6 +20,20 @@ use std::io::{ BufWriter, Write};
 use regex::Regex;
 use std::convert::From;
 use std::path::PathBuf;
+use tantivy::core::query;
+use tantivy::core::query::{parse_query, BoolExpr};
+#[test]
+fn test_parse_query() {
+    // let left = VecPostings::new(vec!(1, 3, 9));
+    // let right = VecPostings::new(vec!(3, 4, 9, 18));
+    // let inter = intersection(&left, &right);
+    // let vals: Vec<DocId> = inter.iter().collect();
+    // assert_eq!(vals, vec!(3, 9));
+    {
+        let (parsed_query, _) = parse_query("toto:titi toto:tutu").unwrap();
+        assert_eq!(parsed_query, BoolExpr::Conjunction(vec!(query::Term(String::from("toto"), String::from("titi")), query::Term(String::from("toto"), String::from("tutu")))));
+    }
+}
 
 #[test]
 fn test_intersection() {
@@ -38,7 +52,7 @@ fn test_tokenizer() {
 
 #[test]
 fn test_indexing() {
-    let directory = Directory::from("/Users/pmasurel/temp/idx").unwrap();
+    let directory = Directory::from_tempdir().unwrap();
     {
         // writing the segment
         let mut index_writer = IndexWriter::open(&directory);
@@ -59,6 +73,7 @@ fn test_indexing() {
         }
 
         let commit_result = index_writer.commit();
+        println!("{:?}", commit_result);
         assert!(commit_result.is_ok());
         // reading the segment
         println!("------");
@@ -68,7 +83,7 @@ fn test_indexing() {
             let mut term_cursor = index_reader.term_cursor();
             loop {
                 match term_cursor.next() {
-                    Some((term, mut doc_cursor)) => {
+                    Some((term, doc_cursor)) => {
                         println!("{:?}", term);
                         for doc in doc_cursor {
                             println!("  Doc {}", doc);
@@ -80,7 +95,6 @@ fn test_indexing() {
                 }
             }
         }
-        assert!(false);
     }
     {
         // TODO add index opening stuff
diff --git a/tests/query.rs b/tests/query.rs
new file mode 100644
index 000000000..e69de29bb