clean code

Author: PinkCrow007

arrow-schema/src/error.rs

@@ -60,6 +60,8 @@ pub enum ArrowError {
     DictionaryKeyOverflowError,
     /// Error when the run end index in a REE array is bigger than the array length
     RunEndIndexOverflowError,
+    /// Error during Variant operations in `arrow-variant`.
+    VariantError(String),
 }
 
 impl ArrowError {
@@ -126,6 +128,9 @@ impl Display for ArrowError {
             ArrowError::RunEndIndexOverflowError => {
                 write!(f, "Run end encoded array index overflow error")
             }
+            ArrowError::VariantError(desc) => {
+                write!(f, "Variant error: {desc}")
+            }
         }
     }
 }

arrow-variant/Cargo.toml

@@ -46,6 +46,7 @@ arrow-data = { workspace = true }
 arrow-schema = { workspace = true, features = ["canonical_extension_types"] }
 serde = { version = "1.0", default-features = false }
 serde_json = { version = "1.0", default-features = false, features = ["std"] }
+indexmap = "2.0.0"
 
 [dev-dependencies]
 arrow-cast = { workspace = true }