Move filter list closer to the actual filters, add docs

2 files changed, 19 insertions, 13 deletions

diff --git a/askama_shared/src/filters/mod.rs b/askama_shared/src/filters/mod.rs
index 75014fa..1f5fa42 100644
--- a/askama_shared/src/filters/mod.rs
+++ b/askama_shared/src/filters/mod.rs
@@ -16,6 +16,23 @@ use std::fmt;
 use super::Result;
 
 
+// This is used by the code generator to decide whether a named filter is part of
+// 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; 9] = [
+    "e",
+    "escape",
+    "format",
+    "lower",
+    "lowercase",
+    "trim",
+    "upper",
+    "uppercase",
+    "json", // Optional feature; reserve the name anyway
+];
+
+
 fn escapable(b: &u8) -> bool {
     *b == b'<' || *b == b'>' || *b == b'&'
 }
diff --git a/askama_shared/src/generator.rs b/askama_shared/src/generator.rs
index 4d101a1..5c4b7f8 100644
--- a/askama_shared/src/generator.rs
+++ b/askama_shared/src/generator.rs
@@ -1,3 +1,4 @@
+use filters;
 use parser::{self, Cond, Expr, Node, Target, WS};
 use path;
 
@@ -262,7 +263,7 @@ impl<'a> Generator<'a> {
             return;
         }
 
-        if BUILT_IN_FILTERS.contains(&name) {
+        if filters::BUILT_IN_FILTERS.contains(&name) {
             self.write(&format!("::askama::filters::{}(&", name));
         } else {
             self.write(&format!("filters::{}(&", name));
@@ -729,15 +730,3 @@ impl<'a, T: 'a> SetChain<'a, T> where T: cmp::Eq + hash::Hash {
 }
 
 type MacroMap<'a> = HashMap<&'a str, (WS, &'a str, Vec<&'a str>, Vec<Node<'a>>, WS)>;
-
-const BUILT_IN_FILTERS: [&str; 9] = [
-    "e",
-    "escape",
-    "format",
-    "lower",
-    "lowercase",
-    "trim",
-    "upper",
-    "uppercase",
-    "json", // Optional feature; reserve the name anyway
-];