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|
use proc_macro2::TokenStream;
use quote::{format_ident, quote};
use syn::{
parenthesized,
parse::{Parse, ParseStream},
spanned::Spanned,
Fields, Token,
};
use crate::{
diagnostic::{DiagnosticConcreteArgs, DiagnosticDef},
utils::{display_pat_members, gen_all_variants_with},
};
use crate::{
fmt::{self, Display},
forward::WhichFn,
};
pub enum Help {
Display(Display),
Field(syn::Member, Box<syn::Type>),
}
impl Parse for Help {
fn parse(input: ParseStream) -> syn::Result<Self> {
let ident = input.parse::<syn::Ident>()?;
if ident == "help" {
let la = input.lookahead1();
if la.peek(syn::token::Paren) {
let content;
parenthesized!(content in input);
let fmt = content.parse()?;
let args = if content.is_empty() {
TokenStream::new()
} else {
fmt::parse_token_expr(&content, false)?
};
let display = Display {
fmt,
args,
has_bonus_display: false,
};
Ok(Help::Display(display))
} else {
input.parse::<Token![=]>()?;
Ok(Help::Display(Display {
fmt: input.parse()?,
args: TokenStream::new(),
has_bonus_display: false,
}))
}
} else {
Err(syn::Error::new(ident.span(), "not a help"))
}
}
}
impl Help {
pub(crate) fn from_fields(fields: &syn::Fields) -> syn::Result<Option<Self>> {
match fields {
syn::Fields::Named(named) => Self::from_fields_vec(named.named.iter().collect()),
syn::Fields::Unnamed(unnamed) => {
Self::from_fields_vec(unnamed.unnamed.iter().collect())
}
syn::Fields::Unit => Ok(None),
}
}
fn from_fields_vec(fields: Vec<&syn::Field>) -> syn::Result<Option<Self>> {
for (i, field) in fields.iter().enumerate() {
for attr in &field.attrs {
if attr.path().is_ident("help") {
let help = if let Some(ident) = field.ident.clone() {
syn::Member::Named(ident)
} else {
syn::Member::Unnamed(syn::Index {
index: i as u32,
span: field.span(),
})
};
return Ok(Some(Help::Field(help, Box::new(field.ty.clone()))));
}
}
}
Ok(None)
}
pub(crate) fn gen_enum(variants: &[DiagnosticDef]) -> Option<TokenStream> {
gen_all_variants_with(
variants,
WhichFn::Help,
|ident, fields, DiagnosticConcreteArgs { help, .. }| {
let (display_pat, display_members) = display_pat_members(fields);
match &help.as_ref()? {
Help::Display(display) => {
let (fmt, args) = display.expand_shorthand_cloned(&display_members);
Some(quote! {
Self::#ident #display_pat => std::option::Option::Some(std::boxed::Box::new(format!(#fmt #args))),
})
}
Help::Field(member, ty) => {
let help = match &member {
syn::Member::Named(ident) => ident.clone(),
syn::Member::Unnamed(syn::Index { index, .. }) => {
format_ident!("_{}", index)
}
};
let var = quote! { __miette_internal_var };
Some(quote! {
Self::#ident #display_pat => {
use miette::macro_helpers::ToOption;
miette::macro_helpers::OptionalWrapper::<#ty>::new().to_option(&#help).as_ref().map(|#var| -> std::boxed::Box<dyn std::fmt::Display + '_> { std::boxed::Box::new(format!("{}", #var)) })
},
})
}
}
},
)
}
pub(crate) fn gen_struct(&self, fields: &Fields) -> Option<TokenStream> {
let (display_pat, display_members) = display_pat_members(fields);
match self {
Help::Display(display) => {
let (fmt, args) = display.expand_shorthand_cloned(&display_members);
Some(quote! {
fn help(&self) -> std::option::Option<std::boxed::Box<dyn std::fmt::Display + '_>> {
#[allow(unused_variables, deprecated)]
let Self #display_pat = self;
std::option::Option::Some(std::boxed::Box::new(format!(#fmt #args)))
}
})
}
Help::Field(member, ty) => {
let var = quote! { __miette_internal_var };
Some(quote! {
fn help(&self) -> std::option::Option<std::boxed::Box<dyn std::fmt::Display + '_>> {
#[allow(unused_variables, deprecated)]
let Self #display_pat = self;
use miette::macro_helpers::ToOption;
miette::macro_helpers::OptionalWrapper::<#ty>::new().to_option(&self.#member).as_ref().map(|#var| -> std::boxed::Box<dyn std::fmt::Display + '_> { std::boxed::Box::new(format!("{}", #var)) })
}
})
}
}
}
}
|
