From 917080a5c27b3310daab135f9bfdbc531cb54186 Mon Sep 17 00:00:00 2001
From: Joe Wilm <joe@jwilm.com>
Date: Sat, 17 Sep 2016 17:02:29 -0700
Subject: Move utf8 parsing into separate crate

---
 Cargo.toml                |   3 +-
 codegen/src/ext/utf8.rs   |   2 +-
 codegen/src/main.rs       |   4 +-
 src/lib.rs                |   3 +-
 src/utf8/mod.rs           |  91 -----------------------
 src/utf8/table.rs         | 184 ----------------------------------------------
 src/utf8/table.rs.in      |  60 ---------------
 src/utf8/types.rs         |  77 -------------------
 utf8parse/Cargo.toml      |   6 ++
 utf8parse/src/lib.rs      |  93 +++++++++++++++++++++++
 utf8parse/src/table.rs    | 184 ++++++++++++++++++++++++++++++++++++++++++++++
 utf8parse/src/table.rs.in |  60 +++++++++++++++
 utf8parse/src/types.rs    |  77 +++++++++++++++++++
 13 files changed, 427 insertions(+), 417 deletions(-)
 delete mode 100644 src/utf8/mod.rs
 delete mode 100644 src/utf8/table.rs
 delete mode 100644 src/utf8/table.rs.in
 delete mode 100644 src/utf8/types.rs
 create mode 100644 utf8parse/Cargo.toml
 create mode 100644 utf8parse/src/lib.rs
 create mode 100644 utf8parse/src/table.rs
 create mode 100644 utf8parse/src/table.rs.in
 create mode 100644 utf8parse/src/types.rs

diff --git a/Cargo.toml b/Cargo.toml
index 1e38f87..494ece6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,4 +3,5 @@ name = "vte"
 version = "0.1.0"
 authors = ["Joe Wilm <joe@jwilm.com>"]
 
-[dependencies]
+[dependencies.utf8parse]
+path = "./utf8parse"
diff --git a/codegen/src/ext/utf8.rs b/codegen/src/ext/utf8.rs
index 5b73081..17ebc22 100644
--- a/codegen/src/ext/utf8.rs
+++ b/codegen/src/ext/utf8.rs
@@ -13,7 +13,7 @@ use syntex_syntax::parse::PResult;
 use syntex_syntax::ptr::P;
 use syntex_syntax::tokenstream::TokenTree;
 
-#[path="../../../src/utf8/types.rs"]
+#[path="../../../utf8parse/src/types.rs"]
 mod types;
 
 use self::types::{State, Action, pack};
diff --git a/codegen/src/main.rs b/codegen/src/main.rs
index 5f8d153..0d21577 100644
--- a/codegen/src/main.rs
+++ b/codegen/src/main.rs
@@ -17,7 +17,7 @@ fn main() {
     // Expand UTF8 parser state table
     let mut registry = syntex::Registry::new();
     ext::utf8::register(&mut registry);
-    let src = &Path::new("../src/utf8/table.rs.in");
-    let dst = &Path::new("../src/utf8/table.rs");
+    let src = &Path::new("../utf8parse/src/table.rs.in");
+    let dst = &Path::new("../utf8parse/src/table.rs");
     registry.expand("utf8_state_table", src, dst).expect("expand utf8_stable_table ok");
 }
diff --git a/src/lib.rs b/src/lib.rs
index 71953fd..f449e13 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -23,9 +23,10 @@
 //! [`Parser`]: struct.Parser.html
 //! [`Perform`]: trait.Perform.html
 //! [Paul Williams' ANSI parser state machine]: http://vt100.net/emu/dec_ansi_parser
+extern crate utf8parse as utf8;
+
 mod table;
 mod definitions;
-mod utf8;
 
 use definitions::{Action, State, unpack};
 
diff --git a/src/utf8/mod.rs b/src/utf8/mod.rs
deleted file mode 100644
index 3d099b1..0000000
--- a/src/utf8/mod.rs
+++ /dev/null
@@ -1,91 +0,0 @@
-//! A table-driven UTF-8 Parser
-//!
-//! This module implements a table-driven UTF-8 parser which should
-//! theoretically contain the minimal number of branches (1). The only branch is
-//! on the `Action` returned from unpacking a transition.
-use std::char;
-
-mod types;
-use self::types::{State, Action, unpack};
-
-mod table;
-use self::table::TRANSITIONS;
-
-/// Handles codepoint and invalid sequence events from the parser.
-pub trait Receiver {
-    /// Code point parsed
-    ///
-    /// Called with the codepoint
-    fn codepoint(&mut self, char);
-
-    /// Invalid sequence encountered
-    fn invalid_sequence(&mut self);
-}
-
-/// A parser for Utf8 Characters
-///
-/// Repeatedly call `advance` with bytes to emit Utf8 characters
-pub struct Parser {
-    point: u32,
-    state: State,
-}
-
-/// Continuation bytes are masked with this value.
-const CONTINUATION_MASK: u8 = 0b0011_1111;
-
-impl Parser {
-    /// Create a new Parser
-    pub fn new() -> Parser {
-        Parser {
-            point: 0,
-            state: State::Ground,
-        }
-    }
-
-    pub fn advance<R>(&mut self, receiver: &mut R, byte: u8)
-        where R: Receiver
-    {
-        let cur = self.state as usize;
-        let change = TRANSITIONS[cur][byte as usize];
-        let (state, action) = unsafe { unpack(change) };
-
-        self.perform_action(receiver, byte, action);
-        self.state = state;
-    }
-
-    fn perform_action<R>(&mut self, receiver: &mut R, byte: u8, action: Action)
-        where R: Receiver
-    {
-        match action {
-            Action::InvalidSequence => {
-                self.point = 0;
-                receiver.invalid_sequence();
-            },
-            Action::EmitByte => {
-                receiver.codepoint(byte as char);
-            },
-            Action::SetByte1 => {
-                let point = self.point | ((byte & CONTINUATION_MASK) as u32);
-                let c = unsafe { char::from_u32_unchecked(point) };
-                self.point = 0;
-
-                receiver.codepoint(c);
-            },
-            Action::SetByte2 => {
-                self.point |= ((byte & CONTINUATION_MASK) as u32) << 6;
-            },
-            Action::SetByte2Top => {
-                self.point |= ((byte & 0b0001_1111) as u32) << 6;
-            },
-            Action::SetByte3 => {
-                self.point |= ((byte & CONTINUATION_MASK) as u32) << 12;
-            },
-            Action::SetByte3Top => {
-                self.point |= ((byte & 0b0000_1111) as u32) << 12;
-            },
-            Action::SetByte4 => {
-                self.point |= ((byte & 0b0000_0111) as u32) << 18;
-            },
-        }
-    }
-}
diff --git a/src/utf8/table.rs b/src/utf8/table.rs
deleted file mode 100644
index 5a1292b..0000000
--- a/src/utf8/table.rs
+++ /dev/null
@@ -1,184 +0,0 @@
-//! UTF-8 Parse Transition Table
-
-/// Transition table for parsing UTF-8. This is built from the grammar described
-/// at https://tools.ietf.org/html/rfc3629#section-4 which I have copied and
-/// formatted below.
-///
-/// # UTF-8 Grammar
-///
-/// ```ignore
-///     UTF8-octets = *( UTF8-char )
-///     UTF8-char   = UTF8-1 / UTF8-2 / UTF8-3 / UTF8-4
-///     UTF8-1      = %x00-7F
-///     UTF8-2      = %xC2-DF UTF8-tail
-///     UTF8-3      = %xE0    %xA0-BF UTF8-tail /
-///                   %xE1-EC 2( UTF8-tail )    /
-///                   %xED    %x80-9F UTF8-tail /
-///                   %xEE-EF 2( UTF8-tail )
-///     UTF8-4      = %xF0    %x90-BF 2( UTF8-tail ) /
-///                   %xF1-F3 3( UTF8-tail )         /
-///                   %xF4    %x80-8F 2( UTF8-tail )
-///     UTF8-tail   = %x80-BF
-/// ```
-///
-/// Not specifying an action in this table is equivalent to specifying
-/// Action::InvalidSequence. Not specifying a state is equivalent to specifying
-/// state::ground.
-pub static TRANSITIONS: [[u8; 256]; 8] =
-    [[16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
-      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
-      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
-      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
-      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
-      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
-      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
-      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
-      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
-      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
-      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8,
-      67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8,
-      67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 100u8, 98u8,
-      98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 101u8,
-      98u8, 98u8, 118u8, 113u8, 113u8, 113u8, 119u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8],
-     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
-      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
-      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
-      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
-      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
-      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8],
-     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
-      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
-      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
-      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
-      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
-      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8],
-     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8,
-      32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8,
-      32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8,
-      32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8,
-      32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8,
-      32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8],
-     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
-      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
-      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
-      51u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8],
-     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
-      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
-      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8],
-     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
-      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
-      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
-      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
-      82u8, 82u8, 82u8, 82u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8],
-     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
-      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
-      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8]];
diff --git a/src/utf8/table.rs.in b/src/utf8/table.rs.in
deleted file mode 100644
index 2acafe7..0000000
--- a/src/utf8/table.rs.in
+++ /dev/null
@@ -1,60 +0,0 @@
-//! UTF-8 Parse Transition Table
-
-/// Transition table for parsing UTF-8. This is built from the grammar described
-/// at https://tools.ietf.org/html/rfc3629#section-4 which I have copied and
-/// formatted below.
-///
-/// # UTF-8 Grammar
-///
-/// ```ignore
-///     UTF8-octets = *( UTF8-char )
-///     UTF8-char   = UTF8-1 / UTF8-2 / UTF8-3 / UTF8-4
-///     UTF8-1      = %x00-7F
-///     UTF8-2      = %xC2-DF UTF8-tail
-///     UTF8-3      = %xE0    %xA0-BF UTF8-tail /
-///                   %xE1-EC 2( UTF8-tail )    /
-///                   %xED    %x80-9F UTF8-tail /
-///                   %xEE-EF 2( UTF8-tail )
-///     UTF8-4      = %xF0    %x90-BF 2( UTF8-tail ) /
-///                   %xF1-F3 3( UTF8-tail )         /
-///                   %xF4    %x80-8F 2( UTF8-tail )
-///     UTF8-tail   = %x80-BF
-/// ```
-///
-/// Not specifying an action in this table is equivalent to specifying
-/// Action::InvalidSequence. Not specifying a state is equivalent to specifying
-/// state::ground.
-pub static TRANSITIONS: [[u8; 256]; 8] = utf8_state_table! {
-    State::Ground => {
-        0x00...0x7f => (State::Ground,      Action::EmitByte),
-        0xc2...0xdf => (State::Tail1,       Action::SetByte2Top),
-        0xe0        => (State::U3_2_e0,     Action::SetByte3Top),
-        0xe1...0xec => (State::Tail2,       Action::SetByte3Top),
-        0xed        => (State::U3_2_ed,     Action::SetByte3Top),
-        0xee...0xef => (State::Tail2,       Action::SetByte3Top),
-        0xf0        => (State::Utf8_4_3_f0, Action::SetByte4),
-        0xf1...0xf3 => (State::Tail3,       Action::SetByte4),
-        0xf4        => (State::Utf8_4_3_f4, Action::SetByte4),
-    },
-    State::U3_2_e0 => {
-        0xa0...0xbf => (State::Tail1, Action::SetByte2),
-    },
-    State::U3_2_ed => {
-        0x80...0x9f => (State::Tail1, Action::SetByte2),
-    },
-    State::Utf8_4_3_f0 => {
-        0x90...0xbf => (State::Tail2, Action::SetByte3),
-    },
-    State::Utf8_4_3_f4 => {
-        0x80...0x8f => (State::Tail2, Action::SetByte3),
-    },
-    State::Tail3 => {
-        0x80...0xbf => (State::Tail2, Action::SetByte3),
-    },
-    State::Tail2 => {
-        0x80...0xbf => (State::Tail1, Action::SetByte2),
-    },
-    State::Tail1 => {
-        0x80...0xbf => (State::Ground, Action::SetByte1),
-    },
-};
diff --git a/src/utf8/types.rs b/src/utf8/types.rs
deleted file mode 100644
index 4c604f4..0000000
--- a/src/utf8/types.rs
+++ /dev/null
@@ -1,77 +0,0 @@
-//! Types supporting the UTF-8 parser
-#![allow(non_camel_case_types)]
-use std::mem;
-
-/// States the parser can be in.
-///
-/// There is a state for each initial input of the 3 and 4 byte sequences since
-/// the following bytes are subject to different conditions than a tail byte.
-#[allow(dead_code)]
-#[derive(Debug, Copy, Clone)]
-pub enum State {
-    /// Ground state; expect anything
-    Ground = 0,
-    /// 3 tail bytes
-    Tail3 = 1,
-    /// 2 tail bytes
-    Tail2 = 2,
-    /// 1 tail byte
-    Tail1 = 3,
-    /// UTF8-3 starting with E0
-    U3_2_e0 = 4,
-    /// UTF8-3 starting with ED
-    U3_2_ed = 5,
-    /// UTF8-4 starting with F0
-    Utf8_4_3_f0 = 6,
-    /// UTF8-4 starting with F4
-    Utf8_4_3_f4 = 7,
-}
-
-/// Action to take when receiving a byte
-#[allow(dead_code)]
-#[derive(Debug, Copy, Clone)]
-pub enum Action {
-    /// Unexpected byte; sequence is invalid
-    InvalidSequence = 0,
-    /// Received valid 7-bit ASCII byte which can be directly emitted.
-    EmitByte = 1,
-    /// Set the bottom continuation byte
-    SetByte1 = 2,
-    /// Set the 2nd-from-last continuation byte
-    SetByte2 = 3,
-    /// Set the 2nd-from-last byte which is part of a two byte sequence
-    SetByte2Top = 4,
-    /// Set the 3rd-from-last continuation byte
-    SetByte3 = 5,
-    /// Set the 3rd-from-last byte which is part of a three byte sequence
-    SetByte3Top = 6,
-    /// Set the top byte of a four byte sequence.
-    SetByte4 = 7,
-}
-
-/// Convert a state and action to a u8
-///
-/// State will be the bottom 4 bits and action the top 4
-#[inline]
-#[allow(dead_code)]
-pub fn pack(state: State, action: Action) -> u8 {
-    ((action as u8) << 4) | (state as u8)
-}
-
-/// Convert a u8 to a state and action
-///
-/// # Unsafety
-///
-/// If this function is called with a byte that wasn't encoded with the `pack`
-/// function in this module, there is no guarantee that a valid state and action
-/// can be produced.
-#[inline]
-pub unsafe fn unpack(val: u8) -> (State, Action) {
-    (
-        // State is stored in bottom 4 bits
-        mem::transmute(val & 0x0f),
-
-        // Action is stored in top 4 bits
-        mem::transmute(val >> 4),
-    )
-}
diff --git a/utf8parse/Cargo.toml b/utf8parse/Cargo.toml
new file mode 100644
index 0000000..882b108
--- /dev/null
+++ b/utf8parse/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "utf8parse"
+version = "0.1.0"
+authors = ["Joe Wilm <joe@jwilm.com>"]
+
+[dependencies]
diff --git a/utf8parse/src/lib.rs b/utf8parse/src/lib.rs
new file mode 100644
index 0000000..9585642
--- /dev/null
+++ b/utf8parse/src/lib.rs
@@ -0,0 +1,93 @@
+//! A table-driven UTF-8 Parser
+//!
+//! This module implements a table-driven UTF-8 parser which should
+//! theoretically contain the minimal number of branches (1). The only branch is
+//! on the `Action` returned from unpacking a transition.
+use std::char;
+
+mod types;
+use self::types::{State, Action, unpack};
+
+mod table;
+use self::table::TRANSITIONS;
+
+/// Handles codepoint and invalid sequence events from the parser.
+pub trait Receiver {
+    /// Called whenever a codepoint is parsed successfully
+    fn codepoint(&mut self, char);
+
+    /// Called when an invalid_sequence is detected
+    fn invalid_sequence(&mut self);
+}
+
+/// A parser for Utf8 Characters
+///
+/// Repeatedly call `advance` with bytes to emit Utf8 characters
+pub struct Parser {
+    point: u32,
+    state: State,
+}
+
+/// Continuation bytes are masked with this value.
+const CONTINUATION_MASK: u8 = 0b0011_1111;
+
+impl Parser {
+    /// Create a new Parser
+    pub fn new() -> Parser {
+        Parser {
+            point: 0,
+            state: State::Ground,
+        }
+    }
+
+    /// Advance the parser
+    ///
+    /// The provider receiver will be called whenever a codepoint is completed or an invalid
+    /// sequence is detected.
+    pub fn advance<R>(&mut self, receiver: &mut R, byte: u8)
+        where R: Receiver
+    {
+        let cur = self.state as usize;
+        let change = TRANSITIONS[cur][byte as usize];
+        let (state, action) = unsafe { unpack(change) };
+
+        self.perform_action(receiver, byte, action);
+        self.state = state;
+    }
+
+    fn perform_action<R>(&mut self, receiver: &mut R, byte: u8, action: Action)
+        where R: Receiver
+    {
+        match action {
+            Action::InvalidSequence => {
+                self.point = 0;
+                receiver.invalid_sequence();
+            },
+            Action::EmitByte => {
+                receiver.codepoint(byte as char);
+            },
+            Action::SetByte1 => {
+                let point = self.point | ((byte & CONTINUATION_MASK) as u32);
+                let c = unsafe { char::from_u32_unchecked(point) };
+                self.point = 0;
+
+                receiver.codepoint(c);
+            },
+            Action::SetByte2 => {
+                self.point |= ((byte & CONTINUATION_MASK) as u32) << 6;
+            },
+            Action::SetByte2Top => {
+                self.point |= ((byte & 0b0001_1111) as u32) << 6;
+            },
+            Action::SetByte3 => {
+                self.point |= ((byte & CONTINUATION_MASK) as u32) << 12;
+            },
+            Action::SetByte3Top => {
+                self.point |= ((byte & 0b0000_1111) as u32) << 12;
+            },
+            Action::SetByte4 => {
+                self.point |= ((byte & 0b0000_0111) as u32) << 18;
+            },
+        }
+    }
+}
diff --git a/utf8parse/src/table.rs b/utf8parse/src/table.rs
new file mode 100644
index 0000000..5a1292b
--- /dev/null
+++ b/utf8parse/src/table.rs
@@ -0,0 +1,184 @@
+//! UTF-8 Parse Transition Table
+
+/// Transition table for parsing UTF-8. This is built from the grammar described
+/// at https://tools.ietf.org/html/rfc3629#section-4 which I have copied and
+/// formatted below.
+///
+/// # UTF-8 Grammar
+///
+/// ```ignore
+///     UTF8-octets = *( UTF8-char )
+///     UTF8-char   = UTF8-1 / UTF8-2 / UTF8-3 / UTF8-4
+///     UTF8-1      = %x00-7F
+///     UTF8-2      = %xC2-DF UTF8-tail
+///     UTF8-3      = %xE0    %xA0-BF UTF8-tail /
+///                   %xE1-EC 2( UTF8-tail )    /
+///                   %xED    %x80-9F UTF8-tail /
+///                   %xEE-EF 2( UTF8-tail )
+///     UTF8-4      = %xF0    %x90-BF 2( UTF8-tail ) /
+///                   %xF1-F3 3( UTF8-tail )         /
+///                   %xF4    %x80-8F 2( UTF8-tail )
+///     UTF8-tail   = %x80-BF
+/// ```
+///
+/// Not specifying an action in this table is equivalent to specifying
+/// Action::InvalidSequence. Not specifying a state is equivalent to specifying
+/// state::ground.
+pub static TRANSITIONS: [[u8; 256]; 8] =
+    [[16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
+      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
+      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
+      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
+      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
+      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
+      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
+      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
+      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
+      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8,
+      16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 16u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8,
+      67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8,
+      67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 67u8, 100u8, 98u8,
+      98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 98u8, 101u8,
+      98u8, 98u8, 118u8, 113u8, 113u8, 113u8, 119u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8],
+     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
+      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
+      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
+      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
+      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
+      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8],
+     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
+      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
+      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
+      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
+      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
+      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8],
+     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8,
+      32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8,
+      32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8,
+      32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8,
+      32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 32u8,
+      32u8, 32u8, 32u8, 32u8, 32u8, 32u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8],
+     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
+      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
+      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
+      51u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8],
+     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
+      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8,
+      51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 51u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8],
+     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
+      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
+      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
+      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
+      82u8, 82u8, 82u8, 82u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8],
+     [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 82u8,
+      82u8, 82u8, 82u8, 82u8, 82u8, 82u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+      0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8]];
diff --git a/utf8parse/src/table.rs.in b/utf8parse/src/table.rs.in
new file mode 100644
index 0000000..2acafe7
--- /dev/null
+++ b/utf8parse/src/table.rs.in
@@ -0,0 +1,60 @@
+//! UTF-8 Parse Transition Table
+
+/// Transition table for parsing UTF-8. This is built from the grammar described
+/// at https://tools.ietf.org/html/rfc3629#section-4 which I have copied and
+/// formatted below.
+///
+/// # UTF-8 Grammar
+///
+/// ```ignore
+///     UTF8-octets = *( UTF8-char )
+///     UTF8-char   = UTF8-1 / UTF8-2 / UTF8-3 / UTF8-4
+///     UTF8-1      = %x00-7F
+///     UTF8-2      = %xC2-DF UTF8-tail
+///     UTF8-3      = %xE0    %xA0-BF UTF8-tail /
+///                   %xE1-EC 2( UTF8-tail )    /
+///                   %xED    %x80-9F UTF8-tail /
+///                   %xEE-EF 2( UTF8-tail )
+///     UTF8-4      = %xF0    %x90-BF 2( UTF8-tail ) /
+///                   %xF1-F3 3( UTF8-tail )         /
+///                   %xF4    %x80-8F 2( UTF8-tail )
+///     UTF8-tail   = %x80-BF
+/// ```
+///
+/// Not specifying an action in this table is equivalent to specifying
+/// Action::InvalidSequence. Not specifying a state is equivalent to specifying
+/// state::ground.
+pub static TRANSITIONS: [[u8; 256]; 8] = utf8_state_table! {
+    State::Ground => {
+        0x00...0x7f => (State::Ground,      Action::EmitByte),
+        0xc2...0xdf => (State::Tail1,       Action::SetByte2Top),
+        0xe0        => (State::U3_2_e0,     Action::SetByte3Top),
+        0xe1...0xec => (State::Tail2,       Action::SetByte3Top),
+        0xed        => (State::U3_2_ed,     Action::SetByte3Top),
+        0xee...0xef => (State::Tail2,       Action::SetByte3Top),
+        0xf0        => (State::Utf8_4_3_f0, Action::SetByte4),
+        0xf1...0xf3 => (State::Tail3,       Action::SetByte4),
+        0xf4        => (State::Utf8_4_3_f4, Action::SetByte4),
+    },
+    State::U3_2_e0 => {
+        0xa0...0xbf => (State::Tail1, Action::SetByte2),
+    },
+    State::U3_2_ed => {
+        0x80...0x9f => (State::Tail1, Action::SetByte2),
+    },
+    State::Utf8_4_3_f0 => {
+        0x90...0xbf => (State::Tail2, Action::SetByte3),
+    },
+    State::Utf8_4_3_f4 => {
+        0x80...0x8f => (State::Tail2, Action::SetByte3),
+    },
+    State::Tail3 => {
+        0x80...0xbf => (State::Tail2, Action::SetByte3),
+    },
+    State::Tail2 => {
+        0x80...0xbf => (State::Tail1, Action::SetByte2),
+    },
+    State::Tail1 => {
+        0x80...0xbf => (State::Ground, Action::SetByte1),
+    },
+};
diff --git a/utf8parse/src/types.rs b/utf8parse/src/types.rs
new file mode 100644
index 0000000..4c604f4
--- /dev/null
+++ b/utf8parse/src/types.rs
@@ -0,0 +1,77 @@
+//! Types supporting the UTF-8 parser
+#![allow(non_camel_case_types)]
+use std::mem;
+
+/// States the parser can be in.
+///
+/// There is a state for each initial input of the 3 and 4 byte sequences since
+/// the following bytes are subject to different conditions than a tail byte.
+#[allow(dead_code)]
+#[derive(Debug, Copy, Clone)]
+pub enum State {
+    /// Ground state; expect anything
+    Ground = 0,
+    /// 3 tail bytes
+    Tail3 = 1,
+    /// 2 tail bytes
+    Tail2 = 2,
+    /// 1 tail byte
+    Tail1 = 3,
+    /// UTF8-3 starting with E0
+    U3_2_e0 = 4,
+    /// UTF8-3 starting with ED
+    U3_2_ed = 5,
+    /// UTF8-4 starting with F0
+    Utf8_4_3_f0 = 6,
+    /// UTF8-4 starting with F4
+    Utf8_4_3_f4 = 7,
+}
+
+/// Action to take when receiving a byte
+#[allow(dead_code)]
+#[derive(Debug, Copy, Clone)]
+pub enum Action {
+    /// Unexpected byte; sequence is invalid
+    InvalidSequence = 0,
+    /// Received valid 7-bit ASCII byte which can be directly emitted.
+    EmitByte = 1,
+    /// Set the bottom continuation byte
+    SetByte1 = 2,
+    /// Set the 2nd-from-last continuation byte
+    SetByte2 = 3,
+    /// Set the 2nd-from-last byte which is part of a two byte sequence
+    SetByte2Top = 4,
+    /// Set the 3rd-from-last continuation byte
+    SetByte3 = 5,
+    /// Set the 3rd-from-last byte which is part of a three byte sequence
+    SetByte3Top = 6,
+    /// Set the top byte of a four byte sequence.
+    SetByte4 = 7,
+}
+
+/// Convert a state and action to a u8
+///
+/// State will be the bottom 4 bits and action the top 4
+#[inline]
+#[allow(dead_code)]
+pub fn pack(state: State, action: Action) -> u8 {
+    ((action as u8) << 4) | (state as u8)
+}
+
+/// Convert a u8 to a state and action
+///
+/// # Unsafety
+///
+/// If this function is called with a byte that wasn't encoded with the `pack`
+/// function in this module, there is no guarantee that a valid state and action
+/// can be produced.
+#[inline]
+pub unsafe fn unpack(val: u8) -> (State, Action) {
+    (
+        // State is stored in bottom 4 bits
+        mem::transmute(val & 0x0f),
+
+        // Action is stored in top 4 bits
+        mem::transmute(val >> 4),
+    )
+}
-- 
cgit