extendr-api: #[extendr]-enum now returns factor,

with levels and tehe right class
CGMossa · Feb 16, 2024 · 9b7c2e5 · 9b7c2e5
1 parent f088997
commit 9b7c2e5
Show file tree

Hide file tree

Showing 2 changed files with 18 additions and 1 deletion.
diff --git a/extendr-api/src/lib.rs b/extendr-api/src/lib.rs
@@ -417,6 +417,12 @@ pub const NA_STRING: Option<&str> = None;
 /// NA value for logical. `r!(NA_LOGICAL)`
 pub const NA_LOGICAL: Rbool = Rbool::na_value();
 
+thread_local! {
+    pub static R_FACTOR_STRING: once_cell::unsync::Lazy<Robj> = once_cell::unsync::Lazy::new(||{
+        "factor".into_robj()
+    });
+}
+
 #[doc(hidden)]
 pub use std::collections::HashMap;
 

diff --git a/extendr-macros/src/extendr_enum.rs b/extendr-macros/src/extendr_enum.rs
@@ -104,7 +104,18 @@ pub(crate) fn extendr_enum(item_enum: syn::ItemEnum) -> proc_macro::TokenStream
             type Error = extendr_api::Error;
             fn try_from(value: #enum_name) -> Result<Self> {
                 let rint: Rint = value.into();
-                Ok(rint.try_into()?)
+                let robj: Robj = rint.try_into()?;
+                unsafe {
+                    #enum_levels_name_strings.with(|strings_enum|{
+                        let strings_enum = once_cell::unsync::Lazy::force(strings_enum);
+                        libR_sys::Rf_setAttrib(robj.get(), libR_sys::R_LevelsSymbol, strings_enum.get());
+                    });
+                    extendr_api::R_FACTOR_STRING.with(|factor_class| {
+                        let factor_class = once_cell::unsync::Lazy::force(factor_class);
+                        libR_sys::Rf_setAttrib(robj.get(), libR_sys::R_ClassSymbol, factor_class.get());
+                    });
+                }
+                Ok(robj)
             }
         }