diff --git a/rust/Cargo.lock b/rust/Cargo.lock
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -50,9 +50,11 @@
 version = "0.1.0"
 dependencies = [
  "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_pcg 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -76,7 +78,7 @@
 
 [[package]]
 name = "lazy_static"
-version = "1.2.0"
+version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -262,7 +264,7 @@
 version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -302,7 +304,7 @@
 "checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
 "checksum cpython 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b489034e723e7f5109fecd19b719e664f89ef925be785885252469e9822fa940"
 "checksum fuchsia-cprng 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "81f7f8eb465745ea9b02e2704612a9946a59fa40572086c6fd49d6ddcf30bf31"
-"checksum lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a374c89b9db55895453a74c1e38861d9deec0b01b405a82516e9d5de4820dea1"
+"checksum lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bc5729f27f159ddd61f4df6228e827e86643d4d3e7c32183cb30a1c08f604a14"
 "checksum libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)" = "2d2857ec59fadc0773853c664d2d18e7198e83883e7060b63c924cb077bd5c74"
 "checksum memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2efc7bc57c883d4a4d6e3246905283d8dae951bb3bd32f49d6ef297f546e1c39"
 "checksum num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0b3a5d7cc97d6d30d8b9bc8fa19bf45349ffe46241e8816f50f62f6d6aaabee1"
diff --git a/rust/hg-core/Cargo.toml b/rust/hg-core/Cargo.toml
--- a/rust/hg-core/Cargo.toml
+++ b/rust/hg-core/Cargo.toml
@@ -9,6 +9,8 @@
 
 [dependencies]
 byteorder = "1.3.1"
+lazy_static = "1.3.0"
 memchr = "2.2.0"
 rand = "> 0.6.4"
 rand_pcg = "> 0.1.0"
+regex = "^1.1"
diff --git a/rust/hg-core/src/ancestors.rs b/rust/hg-core/src/ancestors.rs
--- a/rust/hg-core/src/ancestors.rs
+++ b/rust/hg-core/src/ancestors.rs
@@ -8,9 +8,9 @@
 //! Rust versions of generic DAG ancestors algorithms for Mercurial
 
 use super::{Graph, GraphError, Revision, NULL_REVISION};
+use crate::dagops;
 use std::cmp::max;
 use std::collections::{BinaryHeap, HashSet};
-use crate::dagops;
 
 /// Iterator over the ancestors of a given list of revisions
 /// This is a generic type, defined and implemented for any Graph, so that
diff --git a/rust/hg-core/src/lib.rs b/rust/hg-core/src/lib.rs
--- a/rust/hg-core/src/lib.rs
+++ b/rust/hg-core/src/lib.rs
@@ -4,6 +4,9 @@
 // GNU General Public License version 2 or any later version.
 extern crate byteorder;
 extern crate memchr;
+#[macro_use]
+extern crate lazy_static;
+extern crate regex;
 
 mod ancestors;
 pub mod dagops;
@@ -15,6 +18,11 @@
     pack_dirstate, parse_dirstate, CopyVec, CopyVecEntry, DirstateEntry,
     DirstateParents, DirstateVec,
 };
+mod filepatterns;
+
+pub use filepatterns::{
+    build_single_regex, read_pattern_file, PatternSyntax, PatternTuple,
+};
 
 /// Mercurial revision numbers
 ///
@@ -42,6 +50,8 @@
     fn parents(&self, Revision) -> Result<[Revision; 2], GraphError>;
 }
 
+pub type LineNumber = usize;
+
 #[derive(Clone, Debug, PartialEq)]
 pub enum GraphError {
     ParentOutOfRange(Revision),
@@ -73,3 +83,20 @@
         DirstateParseError::CorruptedEntry(e.to_string())
     }
 }
+
+#[derive(Debug)]
+pub enum PatternError {
+    UnsupportedSyntax(String),
+}
+
+#[derive(Debug)]
+pub enum PatternFileError {
+    IO(std::io::Error),
+    Pattern(PatternError, LineNumber),
+}
+
+impl From<std::io::Error> for PatternFileError {
+    fn from(e: std::io::Error) -> Self {
+        PatternFileError::IO(e)
+    }
+}