Merge pull request #75 from yeslogic/brendanzab/cond-types

Add cond types

Cargo.toml

@@ -15,6 +15,7 @@ keywords = ["binary", "byte", "parser", "parsing", "endian", "big-endian", "litt
 members = [
     "ddl-util",
     "examples/formats/bitmap",
+    "examples/formats/bson",
     "examples/formats/edid",
     "examples/formats/object_id",
     "examples/formats/stl",

ddl-util/src/lib.rs

@@ -3,6 +3,22 @@ extern crate byteorder;
 use byteorder::{BigEndian, LittleEndian, ReadBytesExt};
 use std::io::{self, Read};
 
+#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+pub enum Never {}
+
+#[inline]
+pub fn empty() -> io::Result<()> {
+    Ok(())
+}
+
+#[inline]
+pub fn error<T>() -> io::Result<T> {
+    Err(io::Error::new(
+        io::ErrorKind::InvalidData,
+        "Invalid binary data",
+    ))
+}
+
 #[inline]
 pub fn from_u8<R: Read>(r: &mut R) -> io::Result<u8> {
     r.read_u8()

examples/formats/bson/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "ddl-bson"
+version = "0.0.0"
+license = "Apache-2.0"
+publish = false
+
+[dependencies]
+ddl-util = { path = "../../../ddl-util" }
+
+[build-dependencies]
+ddl = { path = "../../.." }

examples/formats/bson/build.rs

@@ -0,0 +1,26 @@
+extern crate ddl;
+
+use std::env;
+use std::fs::File;
+use std::io::prelude::*;
+use std::str::FromStr;
+
+use ddl::syntax::ast::Program;
+
+fn main() {
+    let src = {
+        let mut src_file = File::open("src/bson.ddl").unwrap();
+        let mut src = String::new();
+        src_file.read_to_string(&mut src).unwrap();
+        src
+    };
+
+    let mut program = Program::from_str(&src).unwrap();
+    program.substitute(&ddl::syntax::ast::base_defs());
+    ddl::syntax::check::check_program(&program).unwrap();
+    let ir = ddl::ir::ast::Program::from(&program);
+
+    let out_dir = env::var("OUT_DIR").unwrap();
+    let mut file = File::create(out_dir + "/bson.rs").unwrap();
+    write!(file, "{}", ddl::codegen::LowerProgram(&ir)).unwrap();
+}

examples/formats/bson/src/bson.ddl

@@ -0,0 +1,85 @@
+/// Binary data
+BinData = struct {
+    /// The number of bytes stored
+    len : i32be,
+    /// Binary data subtype
+    ///
+    /// - `0x00`: Generic binary subtype
+    /// - `0x01`: Function
+    /// - `0x02`: Binary (Old)
+    /// - `0x03`: UUID (Old)
+    /// - `0x04`: UUID
+    /// - `0x05`: MD5
+    /// - `0x80`: User defined
+    subtype : u8,
+    /// The binary data
+    data: [u8; len as u64],
+};
+
+ObjectId = struct {
+    epoch_time: i32be,
+    machine_id: u24be,
+    process_id: u16be,
+    counter: u24be,
+};
+
+Element = struct {
+    elem_type : u8,
+    content: cond {
+        /// 64-bit floating point
+        double : elem_type == 0x01u8 => f64le,
+        // TODO: strings
+        // /// UTF8 string
+        // string : elem_type == 0x02u8 => String,
+        // FIXME: mutual recursion
+        // /// Embedded document
+        // document : elem_type == 0x03u8 => Document,
+        // /// Array
+        // array : elem_type == 0x04u8 => Array,
+        /// Binary data
+        bin_data : elem_type == 0x05u8 => BinData,
+        /// Undefined (value) - deprecated
+        undefined : elem_type == 0x06u8 => empty,
+        /// ObjectId
+        object_id : elem_type == 0x07u8 => ObjectId,
+        /// Boolean
+        ///
+        /// - `0x00`: false
+        /// - `0x01`: true
+        boolean : elem_type == 0x08u8 => u8,
+        /// UTC datetime
+        utc_datetime : elem_type == 0x09u8 => i64le,
+        /// Null value
+        null : elem_type == 0x0au8 => empty,
+        // TODO: Regular Expression
+        // reg_ex : elem_type == 0x0bu8 => RegEx,
+        // TODO: DBPointer — Deprecated
+        // db_pointer : elem_type == 0x0cu8 => DbPointer,
+        // TODO: String
+        // javascript : elem_type == 0x0du8 => String,
+        // TODO: Symbol. Deprecated
+        // symbol : elem_type == 0x0eu8 => Symbol,
+        // TODO: JavaScript code w/ scope
+        // code_with_scope : elem_type == 0x0fu8 => CodeWithScope,
+        /// 32-bit integer
+        int : elem_type == 0x10u8 => i32le,
+        /// Timestamp
+        timestamp : elem_type == 0x11u8 => u64le,
+        /// 64-bit integer
+        long : elem_type == 0x12u8 => i64le,
+        // TODO: 128-bit decimal floating point
+        // number_decimal : elem_type == 0x13u8 => NumberDecimal,
+    },
+};
+
+/// BSON Document
+///
+/// <http://bsonspec.org/spec.html>
+Document = struct {
+    /// Total number of bytes comprising the document.
+    len : i32be,
+    /// The elements that make up this document
+    fields : [Element; 1u8],
+    // /// Terminating byte signalling the end of the file
+    // terminator : u8 where u8 == 0x00,
+};

examples/formats/bson/src/lib.rs

@@ -0,0 +1 @@
+include!(concat!(env!("OUT_DIR"), "/bson.rs"));