add feature-gated case-insensitive timezone parsing

Signed-off-by: Petros Angelatos <petrosagg@gmail.com>

Cargo.toml

@@ -13,12 +13,14 @@ license = "MIT/Apache-2.0"
 [dependencies]
 chrono = { version = "0.4", default-features = false }
 serde = { version = "1", optional = true, default-features = false }
-phf = { version = "0.10", default-features = false }
+phf = { version = "0.10", default-features = false, features = ["uncased"] }
+uncased = { version = "0.9", optional = true, default-features = false }
 
 [features]
 default = ["std"]
 std = []
 filter-by-regex = ["chrono-tz-build/filter-by-regex"]
+uncased_09 = ["uncased", "chrono-tz-build/uncased_09"]
 
 [build-dependencies]
 chrono-tz-build = { path = "./chrono-tz-build", version = "0.0.1" }

chrono-tz-build/Cargo.toml

@@ -12,9 +12,11 @@ documentation = "https://docs.rs/chrono-tz-build"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 [features]
 filter-by-regex = ["regex"]
+uncased_09 = ["uncased"]
 
 [dependencies]
 parse-zoneinfo = { version = "0.3" }
 regex = { default-features = false, version = "1", optional = true }
-phf_codegen = "0.10"
-phf = "0.10"
+phf_codegen = { version = "0.10", default-features = false }
+phf = { version = "0.10", features = ["uncased"] }
+uncased = { version = "0.9", optional = true, default-features = false }

chrono-tz-build/src/lib.rs

@@ -100,6 +100,21 @@ fn write_timezone_file(timezone_file: &mut File, table: &Table) -> io::Result<()
     }
     writeln!(timezone_file, "static TIMEZONES: ::phf::Map<&'static str, Tz> = \n{};", map.build())?;
 
+    #[cfg(feature = "uncased_09")]
+    {
+        writeln!(timezone_file, "use uncased::UncasedStr;\n",)?;
+        let mut map = phf_codegen::Map::new();
+        for zone in &zones {
+            map.entry(uncased::UncasedStr::new(zone), &format!("Tz::{}", convert_bad_chars(zone)));
+        }
+        writeln!(
+            timezone_file,
+            "static TIMEZONES_UNCASED: ::phf::Map<&'static uncased::UncasedStr, Tz> = \n{};",
+            // FIXME(petrosagg): remove this once rust-phf/rust-phf#232 is released
+            map.build().to_string().replace("::std::mem::transmute", "::core::mem::transmute")
+        )?;
+    }
+
     writeln!(
         timezone_file,
         "#[cfg(feature = \"std\")]
@@ -136,9 +151,26 @@ impl FromStr for Tz {{
     writeln!(
         timezone_file,
         "        }}
-    }}
-}}\n"
+    }}"
     )?;
+
+    #[cfg(feature = "uncased_09")]
+    {
+        writeln!(
+            timezone_file,
+            r#"
+    #[cfg(feature = "uncased_09")]
+    /// Parses a timezone string in a case-insensitive way
+    pub fn from_str_insensitive(s: &str) -> Result<Self, ParseError> {{
+        #[cfg(feature = "std")]
+        return TIMEZONES_UNCASED.get(s.into()).cloned().ok_or_else(|| format!("'{{}}' is not a valid timezone", s));
+        #[cfg(not(feature = "std"))]
+        return TIMEZONES_UNCASED.get(s.into()).cloned().ok_or("received invalid timezone");
+    }}"#)?;
+    }
+
+    writeln!(timezone_file, "}}")?;
+
     writeln!(
         timezone_file,
         "impl Debug for Tz {{

src/lib.rs

@@ -158,6 +158,8 @@ extern crate std as core;
 
 extern crate chrono;
 extern crate phf;
+#[cfg(feature = "uncased_09")]
+extern crate uncased;
 
 #[cfg(feature = "serde")]
 mod serde;