Trait syn_ext::ext::AttributeExt

pub trait AttributeExt {
    fn from_meta<M>(meta: M) -> Self
    where
        M: IntoAttribute;
    fn try_meta_mut<F, R>(&mut self, f: F) -> Result<R>
    where
        F: FnOnce(&mut Meta) -> Result<R>;
    fn promoted_list(&self) -> Result<MetaList>;
    fn try_promoted_list_mut<F, R>(&mut self, paren: Paren, f: F) -> Result<R>
    where
        F: FnOnce(&mut MetaList) -> Result<R>;
}

Extension for syn::Attribute

Required methods

fn from_meta<M>(meta: M) -> Self where
    M: IntoAttribute, 

Constructs and returns a new syn::Attribute from syn::Meta

fn try_meta_mut<F, R>(&mut self, f: F) -> Result<R> where
    F: FnOnce(&mut Meta) -> Result<R>, 

Takes a closure and calls it with parsed meta. After call, applys back the manipulated syn::Meta.

1. Try syn::Attribute::parse_meta; return if Err
2. Run f
3. Apply back the manipulated syn::Meta by f.
4. Return the result of f.

Note: Even f returns Err, meta will be made into self.

fn promoted_list(&self) -> Result<MetaList>

Returns a fake promoted list value of syn::MetaList.

If syn::Meta::List, return inner syn::MetaList. If syn::Meta::Path, return a fake syn::MetaList with default paren and empty nested. Otherwise return Err

fn try_promoted_list_mut<F, R>(&mut self, paren: Paren, f: F) -> Result<R> where
    F: FnOnce(&mut MetaList) -> Result<R>, 

Takes a closure and calls it with promoted list of parsed meta. After call, applys back the manipulated syn::MetaList.

1. Try syn::Attribute::parse_meta; return if Err
2. Promote to syn::Meta::List if syn::Meta::Path
3. Run f to inner syn::MetaList
4. Apply back the manipulated syn::Meta by f.
5. Return the result of f.

Implementations on Foreign Types

impl AttributeExt for Attribute

fn from_meta<M>(meta: M) -> Self where
    M: IntoAttribute, 

fn try_meta_mut<F, R>(&mut self, f: F) -> Result<R> where
    F: FnOnce(&mut Meta) -> Result<R>, 

fn promoted_list(&self) -> Result<MetaList>

fn try_promoted_list_mut<F, R>(&mut self, paren: Paren, f: F) -> Result<R> where
    F: FnOnce(&mut MetaList) -> Result<R>, 

Implementors