48 lines
1.6 KiB
Rust
48 lines
1.6 KiB
Rust
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use syn::{Error, GenericArgument, PathArguments, Result, Type};
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pub enum OutputType<'a> {
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Value(&'a Type),
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Result(&'a Type, &'a Type),
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}
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impl<'a> OutputType<'a> {
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pub fn parse(input: &'a Type) -> Result<Self> {
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let ty = if let Type::Path(p) = input {
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if p.path.segments.last().unwrap().ident == "Result" {
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if let PathArguments::AngleBracketed(args) = &p.path.segments[0].arguments {
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if args.args.len() == 0 {
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return Err(Error::new_spanned(input, "Invalid type"));
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}
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let mut res = None;
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for arg in &args.args {
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if let GenericArgument::Type(value_ty) = arg {
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res = Some(OutputType::Result(input, value_ty));
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break;
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}
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}
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if res.is_none() {
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return Err(Error::new_spanned(input, "Invalid type"));
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}
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res.unwrap()
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} else {
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return Err(Error::new_spanned(input, "Invalid type"));
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}
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} else {
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OutputType::Value(input)
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}
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} else if let Type::Reference(_) = input {
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OutputType::Value(input)
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} else {
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return Err(Error::new_spanned(input, "Invalid type"));
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};
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Ok(ty)
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}
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pub fn value_type(&self) -> &Type {
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match self {
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OutputType::Value(ty) => ty,
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OutputType::Result(_, ty) => ty,
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}
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}
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}
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