Initial rust implementation

.travis.yml

@@ -1,22 +1,36 @@
-sudo: false
 # Travis only supports one language per project, so we need to put something
 # here. node_js is as good as any other I suppose.
 language: node_js
 node_js:
   - "0.10"
 
+# For rust, we need to install cargo, rustc.  In order to do that, we'll use
+# apt-get, which requires sudo.
+sudo: true
+
+# The rust-nightly package is only built for 14.04 (Trusty) and 16.04 (Xenial),
+# so we cannot use the default Travis ubuntu image (Precise) for these tests.
+dist: trusty
 
 # Install package dependencies. See
 # http://docs.travis-ci.com/user/installing-dependencies/
 # gulp: required for JS testing
 before_install:
   - npm install -g gulp
+  - yes | sudo add-apt-repository ppa:jonathonf/rustlang 
+  - yes | sudo add-apt-repository ppa:jonathonf/llvm
+  - yes | sudo add-apt-repository ppa:jonathonf/gcc
+  - sudo apt-get update
+
+install:
+  sudo apt-get -y install libstd-rust-1.16 libstd-rust-dev rustc cargo
 
 # Define the list of directories to execute tests in.
 env:
   - TEST_DIR=js
   - TEST_DIR=go
   - TEST_DIR=ruby
+  - TEST_DIR=rust
 
 # Test script to run. This is called once for each TEST_DIR value above.
 script: ./run_tests.sh

run_tests.sh

@@ -32,4 +32,12 @@ if [ "$TEST_DIR" == "ruby" ]; then
   exit
 fi
 
+if [ "$TEST_DIR" == "rust" ]; then
+  curl https://sh.rustup.rs -sSf | sh -s -- -y
+  export PATH=$PATH:$HOME/.cargo/bin
+  rustup update stable
+  cd rust && rustup run stable cargo test
+  exit
+fi
+
 echo "Unknown test directory: $TEST_DIR"

rust/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "open-location-code"
+description = "Library for translating between GPS coordinates (WGS84) and Open Location Code"
+version = "0.1.0"
+authors = ["James Fysh <james.fysh@gmail.com>"]
+license = "Apache-2.0"
+repository = "https://github.com/google/open-location-code"
+keywords = ["geography", "geospatial", "gis", "gps", "olc"]
+exclude = ["rust.iml"]
+
+[dependencies]
+geo = "^0.4.3"

rust/src/codearea.rs

@@ -0,0 +1,31 @@
+use geo::{Point};
+
+pub struct CodeArea {
+    pub south: f64,
+    pub west: f64,
+    pub north: f64,
+    pub east: f64,
+    pub center: Point<f64>,
+    pub code_length: usize,
+}
+
+impl CodeArea {
+    pub fn new(south: f64, west: f64, north: f64, east: f64, code_length: usize) -> CodeArea {
+        CodeArea {
+            south: south, west: west, north: north, east: east,
+            center: Point::new((west + east) / 2f64, (south + north) / 2f64),
+            code_length: code_length
+        }
+    }
+
+    pub fn merge(self, other: CodeArea) -> CodeArea {
+        CodeArea::new(
+            self.south + other.south,
+            self.west + other.west,
+            self.north + other.north,
+            self.east + other.east,
+            self.code_length + other.code_length
+        )
+    }
+}
+

rust/src/consts.rs

@@ -0,0 +1,48 @@
+// A separator used to break the code into two parts to aid memorability.
+pub const SEPARATOR: char = '+';
+
+// The number of characters to place before the separator.
+pub const SEPARATOR_POSITION: usize = 8;
+
+// The character used to pad codes.
+pub const PADDING_CHAR: char = '0';
+pub const PADDING_CHAR_STR: &'static str = "0";
+
+// The character set used to encode the values.
+pub const CODE_ALPHABET: [char; 20] = [
+'2', '3', '4', '5', '6',
+'7', '8', '9', 'C', 'F',
+'G', 'H', 'J', 'M', 'P',
+'Q', 'R', 'V', 'W', 'X',
+];
+
+// The base to use to convert numbers to/from.
+pub const ENCODING_BASE: f64 = 20f64;
+
+// The maximum value for latitude in degrees.
+pub const LATITUDE_MAX: f64 = 90f64;
+
+// The maximum value for longitude in degrees.
+pub const LONGITUDE_MAX: f64 = 180f64;
+
+// Maxiumum code length using lat/lng pair encoding. The area of such a
+// code is approximately 13x13 meters (at the equator), and should be suitable
+// for identifying buildings. This excludes prefix and separator characters.
+pub const PAIR_CODE_LENGTH: usize = 10;
+
+// The resolution values in degrees for each position in the lat/lng pair
+// encoding. These give the place value of each position, and therefore the
+// dimensions of the resulting area.
+pub const PAIR_RESOLUTIONS: [f64; 5] = [
+    20.0f64, 1.0f64, 0.05f64, 0.0025f64, 0.000125f64
+];
+
+// Number of columns in the grid refinement method.
+pub const GRID_COLUMNS: f64 = 4f64;
+
+// Number of rows in the grid refinement method.
+pub const GRID_ROWS: f64 = 5f64;
+
+// Minimum length of a code that can be shortened.
+pub const MIN_TRIMMABLE_CODE_LEN: usize = 6;
+