codegen: Add a nameslug filter

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/src/codegen.rs b/src/codegen.rs
index 0cb63fe..f798b25 100644
--- a/src/codegen.rs
+++ b/src/codegen.rs
@@ -64,6 +64,7 @@ fn tera(tmplspec: &TemplateSpec) -> Result<Tera> {
     // only, so we use a glob that doesn't match anything.
     let mut tera = Tera::new(&"*notexist").expect("new");
     tera.register_filter("base64", base64);
+    tera.register_filter("nameslug", nameslug);
     tera.add_template_file(tmplspec.template_filename(), Some("template"))?;
     Ok(tera)
 }
@@ -90,6 +91,25 @@ fn base64(v: &Value, _: &HashMap<String, Value>) -> tera::Result<Value> {
     }
 }
 
+fn nameslug(name: &Value, _: &HashMap<String, Value>) -> tera::Result<Value> {
+    match name {
+        Value::String(s) => {
+            let newname = s
+                .chars()
+                .map(|c| match c {
+                    'a'..='z' => c,
+                    'A'..='Z' => c.to_ascii_lowercase(),
+                    _ => '_',
+                })
+                .collect();
+            Ok(Value::String(newname))
+        }
+        _ => Err(tera::Error::msg(
+            "can only create nameslugs from strings".to_string(),
+        )),
+    }
+}
+
 #[derive(Debug, Serialize)]
 pub struct Func {
     pub source: PathBuf,