build script to convert json locales at compile time

Cargo.toml

@@ -2,7 +2,7 @@
 name = "chrono-locale"
 version = "0.1.0"
 authors = ["Alessandro Pellizzari <alex@amiran.it>"]
-# build = "build.rs"
+build = "build.rs"
 
 [dependencies]
 chrono = "0.4"

build.rs

@@ -1,62 +1,174 @@
 extern crate walkdir;
+extern crate serde;
+#[macro_use]
+extern crate serde_derive;
+extern crate serde_json;
 
 use std::env;
 use std::fs::File;
-use std::io::Write;
+use std::io::{Write, Read, Error as IoError};
 use std::path::Path;
+use serde_json::{Error as JsonError};
 
-use walkdir::WalkDir;
+use walkdir::{WalkDir, DirEntry};
 
+#[derive(Deserialize)]
 pub struct Locale {
-	short_months: Vec<String>,
-	long_months: Vec<String>,
-	short_weekdays: Vec<String>,
-	long_weekdays: Vec<String>,
+	short_months: Option<Vec<String>>,
+	long_months: Option<Vec<String>>,
+	short_weekdays: Option<Vec<String>>,
+	long_weekdays: Option<Vec<String>>,
 }
 
-
 fn main() {
 	let out_dir = env::var("OUT_DIR").unwrap();
 	let dest_path = Path::new(&out_dir).join("locales.rs");
 	let mut f = File::create(&dest_path).unwrap();
 
-	f.write_all(r###"
-		use std::collections::HashMap;
+	let _ = f.write_all(r#####"lazy_static! {
+		pub static ref LOCALES: Locales = {
+			let mut res = Locales {
+				short_months: HashMap::new(),
+				long_months: HashMap::new(),
+				short_weekdays: HashMap::new(),
+				long_weekdays: HashMap::new(),
+			};
 
-		pub type Locales = HashMap<String, Locale>;
+			res.short_months.insert(
+				"C".into(),
+				vec!["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"],
+			);
 
-		pub struct Locale {
-			short_months: Vec<String>,
-			long_months: Vec<String>,
-			short_weekdays: Vec<String>,
-			long_weekdays: Vec<String>,
-		}
+			res.long_months.insert(
+				"C".into(),
+				vec![
+					"January",
+					"February",
+					"March",
+					"April",
+					"May",
+					"June",
+					"July",
+					"August",
+					"September",
+					"October",
+					"November",
+					"December",
+				],
+			);
 
-		lazy_static! {
-			static ref LOCALES: Locales = {
-				let mut res = HashMap::new();
-"###.as_bytes()).unwrap();
+			res.short_weekdays
+				.insert("C".into(), vec!["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]);
 
+			res.long_weekdays.insert(
+				"C".into(),
+				vec!["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"],
+			);
+	"#####.as_bytes());
 
 	println!("Building...");
 	for entry in WalkDir::new("locales") {
 		let entry = entry.unwrap();
-		println!("{}", entry.path().display());
+		println!("Found {}", entry.path().display());
 
 		if entry.path().extension().map(|e| e != "json").unwrap_or(false) {
 			println!("Not a json file");
 			continue
 		}
 
+		let locale_name = entry.path().file_stem().map(|n| n.to_string_lossy());
+		if locale_name.is_none() {
+			continue;
+		}
 
 
+		let locale_name = locale_name.unwrap().to_string();
+		if let Ok(locale_data) = load_locale(&entry) {
+			if let Some(long_months) = locale_data.long_months {
+				if long_months.len() == 12 {
+					let _ = f.write_all(format!(
+						"res.long_months.insert(\"{}\".into(), vec![{}]);\n",
+						locale_name,
+						long_months
+							.iter()
+							.map(|s| format!("\"{}\"", s))
+							.collect::<Vec<String>>()
+							.join(",")
+					).as_bytes()).unwrap();
+				}
+			}
+
+			if let Some(short_months) = locale_data.short_months {
+				if short_months.len() == 12 {
+					let _ = f.write_all(format!(
+						"res.short_months.insert(\"{}\".into(), vec![{}]);\n",
+						locale_name,
+						short_months
+							.iter()
+							.map(|s| format!("\"{}\"", s))
+							.collect::<Vec<String>>()
+							.join(",")
+					).as_bytes()).unwrap();
+				}
+			}
+
+			if let Some(long_weekdays) = locale_data.long_weekdays {
+				if long_weekdays.len() == 7 {
+					let _ = f.write_all(format!(
+						"res.long_weekdays.insert(\"{}\".into(), vec![{}]);\n",
+						locale_name,
+						long_weekdays
+							.iter()
+							.map(|s| format!("\"{}\"", s))
+							.collect::<Vec<String>>()
+							.join(",")
+					).as_bytes()).unwrap();
+				}
+			}
+
+			if let Some(short_weekdays) = locale_data.short_weekdays {
+				if short_weekdays.len() == 7 {
+					let _ = f.write_all(format!(
+						"res.short_weekdays.insert(\"{}\".into(), vec![{}]);\n",
+						locale_name,
+						short_weekdays
+							.iter()
+							.map(|s| format!("\"{}\"", s))
+							.collect::<Vec<String>>()
+							.join(",")
+					).as_bytes()).unwrap();
+				}
+			}
+		}
 	}
 
-
-	f.write_all(r###"
-
-				res
+	let _ = f.write_all(r####"		res
 			};
 		}
-    "###.as_bytes()).unwrap();
+		"####.as_bytes());
+}
+
+fn load_locale(entry: &DirEntry) -> Result<Locale, BuildError> {
+	let mut locale_data = String::new();
+	let mut f = File::open(entry.path())?;
+	f.read_to_string(&mut locale_data)?;
+	let locale = serde_json::from_str::<Locale>(&locale_data)?;
+	Ok(locale)
+}
+
+enum BuildError {
+	Io(IoError),
+	Json(JsonError),
+}
+
+impl From<IoError> for BuildError {
+	fn from(e: IoError) -> Self {
+		BuildError::Io(e)
+	}
+}
+
+impl From<JsonError> for BuildError {
+	fn from(e: JsonError) -> Self {
+		BuildError::Json(e)
+	}
 }

src/locales-old.rs

@@ -0,0 +1,55 @@
+// This file will be overwritten by build.rs during compilation
+
+use std::collections::HashMap;
+
+#[derive(Debug)]
+pub struct Locales {
+	pub short_months: HashMap<String, Vec<&'static str>>,
+	pub long_months: HashMap<String, Vec<&'static str>>,
+	pub short_weekdays: HashMap<String, Vec<&'static str>>,
+	pub long_weekdays: HashMap<String, Vec<&'static str>>,
+}
+
+lazy_static! {
+	pub static ref LOCALES: Locales = {
+		let mut res = Locales {
+			short_months: HashMap::new(),
+			long_months: HashMap::new(),
+			short_weekdays: HashMap::new(),
+			long_weekdays: HashMap::new(),
+		};
+
+		res.short_months.insert(
+			"C".into(),
+			vec!["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"],
+		);
+
+		res.long_months.insert(
+			"C".into(),
+			vec![
+				"January",
+				"February",
+				"March",
+				"April",
+				"May",
+				"June",
+				"July",
+				"August",
+				"September",
+				"October",
+				"November",
+				"December",
+			],
+		);
+
+		res.short_weekdays
+			.insert("C".into(), vec!["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]);
+
+		res.long_weekdays.insert(
+			"C".into(),
+			vec!["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"],
+		);
+
+		res
+	};
+}

src/locales.rs

@@ -1,7 +1,6 @@
-// This file will be overwritten by build.rs during compilation
-
 use std::collections::HashMap;
 
+#[derive(Debug)]
 pub struct Locales {
 	pub short_months: HashMap<String, Vec<&'static str>>,
 	pub long_months: HashMap<String, Vec<&'static str>>,
@@ -9,46 +8,5 @@ pub struct Locales {
 	pub long_weekdays: HashMap<String, Vec<&'static str>>,
 }
 
-lazy_static! {
-	pub static ref LOCALES: Locales = {
-		let mut res = Locales {
-			short_months: HashMap::new(),
-			long_months: HashMap::new(),
-			short_weekdays: HashMap::new(),
-			long_weekdays: HashMap::new(),
-		};
+include!(concat!(env!("OUT_DIR"), "/locales.rs"));
 
-		res.short_months.insert(
-			"C".into(),
-			vec!["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"],
-		);
-
-		res.long_months.insert(
-			"C".into(),
-			vec![
-				"January",
-				"February",
-				"March",
-				"April",
-				"May",
-				"June",
-				"July",
-				"August",
-				"September",
-				"October",
-				"November",
-				"December",
-			],
-		);
-
-		res.short_weekdays
-			.insert("C".into(), vec!["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]);
-
-		res.long_weekdays.insert(
-			"C".into(),
-			vec!["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"],
-		);
-
-		res
-	};
-}