Module util

Utility types for attribute parsing.

Modules

• parse_expr
  Functions to use with #[darling(with = "...")] that control how quoted values in Meta instances are parsed into Expr fields.

Structs

• Flag
  A meta-item that can be present as a word - with no value - or absent.
• IdentString
  A wrapper for an Ident which also keeps the value as a string.
• Ignored
  An efficient way of discarding data from a syntax element.
• PathList
  A list of syn::Path instances. This type is used to extract a list of paths from an attribute.
• ShapeSet
  A set of Shape values, which correctly handles the relationship between newtype and tuple shapes.
• SpannedValue
  A value and an associated position in source code. The main use case for this is to preserve position information to emit warnings from proc macros. You can use a SpannedValue<T> as a field in any struct that implements or derives any of darling’s core traits.
• WithOriginal
  A container to parse some syntax and retain access to the original.

Enums

• Override
  A value which can inherit a default value or have an explicit value specified.
• Shape
  Description of how fields in a struct or variant are syntactically laid out.

Traits

• AsShape
  Get the “shape” of a fields container, such as a struct or variant.

Functions

• parse_attribute_to_meta_list
  Try to parse an attribute into a meta list. Path-type meta values are accepted and returned as empty lists with their passed-in path. Name-value meta values and non-meta attributes will cause errors to be returned.
• path_to_string
  Transform Rust paths to a readable and comparable string.