derive_builder_core_fork_arti/
default_expression.rs

1use crate::BlockContents;
2use quote::{ToTokens, TokenStreamExt};
3
4/// A `DefaultExpression` can be either explicit or refer to the canonical trait.
5#[derive(Debug, Clone)]
6pub enum DefaultExpression {
7    Explicit(BlockContents),
8    Trait,
9}
10
11impl DefaultExpression {
12    #[cfg(test)]
13    pub fn explicit<I: Into<BlockContents>>(content: I) -> Self {
14        DefaultExpression::Explicit(content.into())
15    }
16}
17
18impl darling::FromMeta for DefaultExpression {
19    fn from_word() -> darling::Result<Self> {
20        Ok(DefaultExpression::Trait)
21    }
22
23    fn from_value(value: &syn::Lit) -> darling::Result<Self> {
24        Ok(Self::Explicit(BlockContents::from_value(value)?))
25    }
26}
27
28impl ToTokens for DefaultExpression {
29    fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
30        match *self {
31            Self::Explicit(ref block) => block.to_tokens(tokens),
32            Self::Trait => tokens.append_all(quote!(
33                ::derive_builder::export::core::default::Default::default()
34            )),
35        }
36    }
37}

derive_builder_core_fork_arti/default_expression.rs

derive_builder_core_fork_arti/
default_expression.rs