Add f64 filter

1 files changed, 19 insertions, 1 deletions

diff --git a/askama_shared/src/filters/mod.rs b/askama_shared/src/filters/mod.rs
index 404abd7..a6d2ba6 100644
--- a/askama_shared/src/filters/mod.rs
+++ b/askama_shared/src/filters/mod.rs
@@ -22,7 +22,7 @@ use escaping::{self, MarkupDisplay};
 // Askama or should refer to a local `filters` module. It should contain all the
 // filters shipped with Askama, even the optional ones (since optional inclusion
 // in the const vector based on features seems impossible right now).
-pub const BUILT_IN_FILTERS: [&str; 20] = [
+pub const BUILT_IN_FILTERS: [&str; 21] = [
     "abs",
     "capitalize",
     "center",
@@ -30,6 +30,7 @@ pub const BUILT_IN_FILTERS: [&str; 20] = [
     "escape",
     "format",
     "indent",
+    "into_f64",
     "into_isize",
     "join",
     "linebreaks",
@@ -161,6 +162,14 @@ pub fn indent(s: &fmt::Display, width: &usize) -> Result<String> {
     Ok(indented)
 }
 
+/// Casts number to f64
+pub fn into_f64<T>(number: T) -> Result<f64>
+where
+    T: NumCast,
+{
+    number.to_f64().ok_or(Fmt(fmt::Error))
+}
+
 /// Casts number to isize
 pub fn into_isize<T>(number: T) -> Result<isize>
 where
@@ -313,6 +322,15 @@ mod tests {
     }
 
     #[test]
+    fn test_into_f64() {
+        assert_eq!(into_f64(1).unwrap(), 1.0 as f64);
+        assert_eq!(into_f64(1.9).unwrap(), 1.9 as f64);
+        assert_eq!(into_f64(-1.9).unwrap(), -1.9 as f64);
+        assert_eq!(into_f64(INFINITY as f32).unwrap(), INFINITY);
+        assert_eq!(into_f64(-INFINITY as f32).unwrap(), -INFINITY);
+    }
+
+    #[test]
     fn test_into_isize() {
         assert_eq!(into_isize(1).unwrap(), 1 as isize);
         assert_eq!(into_isize(1.9).unwrap(), 1 as isize);