WIP

3 files changed, 341 insertions, 0 deletions

diff --git a/src/definitions.rs b/src/definitions.rs
new file mode 100644
index 0000000..f887559
--- /dev/null
+++ b/src/definitions.rs
@@ -0,0 +1,74 @@
+#[derive(Debug)]
+pub enum State {
+   Anywhere = 0,
+   CsiEntry = 1,
+   CsiIgnore = 2,
+   CsiIntermediate = 3,
+   CsiParam = 4,
+   DcsEntry = 5,
+   DcsIgnore = 6,
+   DcsIntermediate = 7,
+   DcsParam = 8,
+   DcsPassthrough = 9,
+   Escape = 10,
+   EscapeIntermediate = 11,
+   Ground = 12,
+   OscString = 13,
+   SosPmApcString = 14,
+   Unused__ = 15,
+}
+
+#[derive(Debug)]
+pub enum Action {
+   None = 0,
+   Clear = 1,
+   Collect = 2,
+   CsiDispatch = 3,
+   EscDispatch = 4,
+   Execute = 5,
+   Hook = 6,
+   Ignore = 7,
+   OscEnd = 8,
+   OscPut = 9,
+   OscStart = 10,
+   Param = 11,
+   Print = 12,
+   Put = 13,
+   Unhook = 14,
+   Unused__ = 15,
+}
+
+/// Unpack a u8 into a State and Action
+///
+/// The implementation of this assumes that there are *precisely* 16 variants for both Action and
+/// State. Furthermore, it assumes that the enums are tag-only; that is, there is no data in any
+/// variant.
+///
+/// Bad things will happen if those invariants are violated.
+#[inline(always)]
+fn unpack(delta: u8) -> (State, Action) {
+    (
+        // Action is stored in bottom 4 bits
+        unsafe { ::std::mem::transmute(delta & 0x0f) },
+
+        // State is stored in top 4 bits
+        unsafe { ::std::mem::transmute(delta >> 4) },
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{State, Action, unpack};
+    #[test]
+    fn unpack_state_action() {
+        match unpack(0xee) {
+            (State::SosPmApcString, Action::Unhook) => (),
+            _ => panic!("unpack failed"),
+        }
+
+        match unpack(0xff) {
+            (State::Unused__, Action::Unused__) => (),
+            _ => panic!("unpack failed"),
+        }
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..d7dadad
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,53 @@
+mod table;
+mod definitions;
+
+pub use definitions::{Action, State, unpack};
+
+use table::{EXIT_ACTIONS, ENTRY_ACTIONS, STATE_CHANGE};
+
+impl State {
+    /// Get exit action for this state
+    #[inline(always)]
+    pub fn exit_action(&self) -> Action {
+        unsafe {
+            ::table::EXIT_ACTIONS.get_unchecked(*self as usize)
+        }
+    }
+
+    /// Get entry action for this state
+    #[inline(always)]
+    pub fn entry_action(&self) -> Action {
+        unsafe {
+            ::table::ENTRY_ACTIONS.get_unchecked(*self as usize)
+        }
+    }
+}
+
+
+// struct StateMachine<P: Parser> {
+//     state: State,
+// }
+// 
+// trait Parser {
+//     fn csi_entry(&mut self, c: char);
+//     fn csi_param(&mut self, c: char);
+// }
+// 
+// struct Foo;
+// 
+// impl Parser for Foo {
+//     fn csi_entry(&mut self, c: char) {
+//         println!("csi_entry char={:?}", c);
+//     }
+//     fn csi_param(&mut self, c: char) {
+//         println!("csi_param char={:?}", c);
+//     }
+// }
+// 
+// #[test]
+// fn it_works() {
+//     let table: u8 = &[Parser::csi_entry, Parser::csi_param];
+//     let mut foo = Foo;
+//     table[0](&mut foo, 'b');
+// }
+
diff --git a/src/table.rs.in b/src/table.rs.in
new file mode 100644
index 0000000..9c39f5e
--- /dev/null
+++ b/src/table.rs.in
@@ -0,0 +1,214 @@
+/// This is the state change table. It's indexed first by current state and then by the next
+/// character in the pty stream.
+///
+/// TODO implement a syntax extension that runs via syntex in build.rs to actually turn this into a
+/// table.
+static STATE_CHANGE: [[u8; 256]; 16] = state_table! {
+    State::Anywhere => {
+        0x18        => (Action::Execute, State::Ground),
+        0x1a        => (Action::Execute, State::Ground),
+        0x80...0x8f => (Action::Execute, State::Ground),
+        0x91...0x97 => (Action::Execute, State::Ground),
+        0x99        => (Action::Execute, State::Ground),
+        0x9a        => (Action::Execute, State::Ground),
+        0x9c        => (Action::Execute, State::Ground),
+        0x1b        => State::Escape,
+        0x98        => State::SosPmApcString,
+        0x9e        => State::SosPmApcString,
+        0x9f        => State::SosPmApcString,
+        0x90        => State::DcsEntry,
+        0x9d        => State::OscString,
+        0x9b        => State::CsiEntry,
+    },
+
+    State::Ground => {
+        0x00...0x17 => Action::Execute,
+        0x19        => Action::Execute,
+        0x1c...0x1f => Action::Execute,
+        0x20...0x7f => Action::Print,
+        0x80...0x8f => Action::Execute,
+        0x91...0x9a => Action::Execute,
+        0x9c        => Action::Execute
+    },
+
+    State::Escape => {
+        0x00...0x17 => Action::Execute,
+        0x19        => Action::Execute,
+        0x1c...0x1f => Action::Execute,
+        0x7f        => Action::Ignore,
+        0x20...0x2f => (Action::Collect, State::EscapeIntermediate),
+        0x30...0x4f => (Action::EscDispatch, State::Ground),
+        0x51...0x57 => (Action::EscDispatch, State::Ground),
+        0x59        => (Action::EscDispatch, State::Ground),
+        0x5a        => (Action::EscDispatch, State::Ground),
+        0x5c        => (Action::EscDispatch, State::Ground),
+        0x60...0x7e => (Action::EscDispatch, State::Ground),
+        0x5b        => State::CsiEntry,
+        0x5d        => State::OscString,
+        0x50        => State::DcsEntry,
+        0x58        => State::SosPmApcString,
+        0x5e        => State::SosPmApcString,
+        0x5f        => State::SosPmApcString,
+    },
+
+    State::EscapeIntermediate => {
+        0x00...0x17 => Action::Execute,
+        0x19        => Action::Execute,
+        0x1c...0x1f => Action::Execute,
+        0x20...0x2f => Action::Collect,
+        0x7f        => Action::Ignore,
+        0x30...0x7e => (Action::EscDispatch, State::Ground)
+    },
+
+    State::CsiEntry => {
+        0x00...0x17 => Action::Execute,
+        0x19        => Action::Execute,
+        0x1c...0x1f => Action::Execute,
+        0x7f        => Action::Ignore,
+        0x20...0x2f => (Action::Collect, State::CsiIntermediate),
+        0x3a        => State::CsiIgnore,
+        0x30...0x39 => (Action::Param, State::CsiParam),
+        0x3b        => (Action::Param, State::CsiParam),
+        0x3c...0x3f => (Action::Collect, State::CsiParam),
+        0x40...0x7e => (Action::CsiDispatch, State::Ground)
+    },
+
+    State::CsiIgnore => {
+        0x00...0x17 => Action::Execute,
+        0x19        => Action::Execute,
+        0x1c...0x1f => Action::Execute,
+        0x20...0x3f => Action::Ignore,
+        0x7f        => Action::Ignore,
+        0x40...0x7e => State::Ground,
+    },
+
+    State::CsiParam => {
+        0x00...0x17 => Action::Execute,
+        0x19        => Action::Execute,
+        0x1c...0x1f => Action::Execute,
+        0x30...0x39 => Action::Param,
+        0x3b        => Action::Param,
+        0x7f        => Action::Ignore,
+        0x3a        => State::CsiIgnore,
+        0x3c...0x3f => State::CsiIgnore,
+        0x20...0x2f => (Action::Collect, State::CsiIntermediate),
+        0x40...0x7e => (Action::CsiDispatch, State::Ground)
+    },
+
+    State::CsiIntermediate => {
+        0x00...0x17 => Action::Execute,
+        0x19        => Action::Execute,
+        0x1c...0x1f => Action::Execute,
+        0x20...0x2f => Action::Collect,
+        0x7f        => Action::Ignore,
+        0x30...0x3f => State::CsiIgnore,
+        0x40...0x7e => (Action::CsiDispatch, State::Ground),
+    },
+
+    State::DcsEntry => {
+        0x00...0x17 => Action::Ignore,
+        0x19        => Action::Ignore,
+        0x1c...0x1f => Action::Ignore,
+        0x7f        => Action::Ignore,
+        0x3a        => State::DcsIgnore,
+        0x20...0x2f => (Action::Collect, State::DcsIntermediate),
+        0x30...0x39 => (Action::Param, State::DcsParam),
+        0x3b        => (Action::Param, State::DcsParam),
+        0x3c...0x3f => (Action::Collect, State::DcsParam),
+        0x40...0x7e => State::DcsPassthrough
+    },
+
+    State::DcsIntermediate => {
+        0x00...0x17 => Action::Ignore,
+        0x19        => Action::Ignore,
+        0x1c...0x1f => Action::Ignore,
+        0x20...0x2f => Action::Collect,
+        0x7f        => Action::Ignore,
+        0x30...0x3f => State::DcsIgnore,
+        0x40...0x7e => State::DcsPassthrough
+    },
+
+    State::DcsIgnore => {
+        0x00...0x17 => Action::Ignore,
+        0x19        => Action::Ignore,
+        0x1c...0x1f => Action::Ignore,
+        0x20...0x7f => Action::Ignore,
+        0x9c        => State::Ground
+    },
+
+    State::DcsParam => {
+        0x00...0x17 => Action::Ignore,
+        0x19        => Action::Ignore,
+        0x1c...0x1f => Action::Ignore,
+        0x30...0x39 => Action::Param,
+        0x3b        => Action::Param,
+        0x7f        => Action::Ignore,
+        0x3a        => State::DcsIgnore,
+        0x3c...0x3f => State::DcsIgnore,
+        0x20...0x2f => (Action::Collect, State::DcsIntermediate),
+        0x40...0x7e => State::DcsPassthrough
+    },
+
+    State::DcsPassthrough => {
+        0x00...0x17 => Action::Put,
+        0x19        => Action::Put,
+        0x1c...0x1f => Action::Put,
+        0x20...0x7e => Action::Put,
+        0x7f        => Action::Ignore,
+        0x9c        => State::Ground,
+    },
+
+    State::SosPmApcString => {
+        0x00...0x17 => Action::Ignore,
+        0x19        => Action::Ignore,
+        0x1c...0x1f => Action::Ignore,
+        0x20...0x7f => Action::Ignore,
+        0x9c       => State::Ground
+    },
+
+    State::OscString => {
+        0x00...0x17 => Action::Ignore,
+        0x19        => Action::Ignore,
+        0x1c...0x1f => Action::Ignore,
+        0x20...0x7f => Action::OscPut,
+        0x9c        => State::Ground,
+    }
+};
+
+static ENTRY_ACTIONS: &'static [Action] = &[
+   Action::None,     // State::Anywhere
+   Action::Clear,    // State::CsiEntry
+   Action::None,     // State::CsiIgnore
+   Action::None,     // State::CsiIntermediate
+   Action::None,     // State::CsiParam
+   Action::Clear,    // State::DcsEntry
+   Action::None,     // State::DcsIgnore
+   Action::None,     // State::DcsIntermediate
+   Action::None,     // State::DcsParam
+   Action::Hook,     // State::DcsPassthrough
+   Action::Clear,    // State::Escape
+   Action::None,     // State::EscapeIntermediate
+   Action::None,     // State::Ground
+   Action::OscStart, // State::OscString
+   Action::None,     // State::SosPmApcString
+   Action::None,     // State::Unused__
+];
+
+static EXIT_ACTIONS: &'static [Action] = &[
+   Action::None,   // State::Anywhere
+   Action::None,   // State::CsiEntry
+   Action::None,   // State::CsiIgnore
+   Action::None,   // State::CsiIntermediate
+   Action::None,   // State::CsiParam
+   Action::None,   // State::DcsEntry
+   Action::None,   // State::DcsIgnore
+   Action::None,   // State::DcsIntermediate
+   Action::None,   // State::DcsParam
+   Action::Unhook, // State::DcsPassthrough
+   Action::None,   // State::Escape
+   Action::None,   // State::EscapeIntermediate
+   Action::None,   // State::Ground
+   Action::OscEnd, // State::OscString
+   Action::None,   // State::SosPmApcString
+   Action::None,   // State::Unused__
+];