1 files changed, 37 insertions, 0 deletions
diff --git a/ops/attrs.rs b/ops/attrs.rs
new file mode 100644
index 000000000..95374ef36
--- /dev/null
+++ b/ops/attrs.rs
@@ -0,0 +1,37 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+use syn::{
+  parse::{Parse, ParseStream},
+  punctuated::Punctuated,
+  Error, Ident, Result, Token,
+};
+
+#[derive(Copy, Clone, Debug, Default)]
+pub struct Attributes {
+  pub is_unstable: bool,
+  pub is_v8: bool,
+  pub must_be_fast: bool,
+  pub deferred: bool,
+}
+
+impl Parse for Attributes {
+  fn parse(input: ParseStream) -> Result<Self> {
+    let vars = Punctuated::<Ident, Token![,]>::parse_terminated(input)?;
+
+    let vars: Vec<_> = vars.iter().map(Ident::to_string).collect();
+    let vars: Vec<_> = vars.iter().map(String::as_str).collect();
+    for var in vars.iter() {
+      if !["unstable", "v8", "fast", "deferred"].contains(var) {
+        return Err(Error::new(
+          input.span(),
+          "invalid attribute, expected one of: unstable, v8, fast, deferred",
+        ));
+      }
+    }
+    Ok(Self {
+      is_unstable: vars.contains(&"unstable"),
+      is_v8: vars.contains(&"v8"),
+      must_be_fast: vars.contains(&"fast"),
+      deferred: vars.contains(&"deferred"),
+    })
+  }
+}