miette/miette-derive/src/severity.rs

110 lines
3.8 KiB
Rust

use proc_macro2::{Span, TokenStream};
use quote::quote;
use syn::{
parenthesized,
parse::{Parse, ParseStream},
Token,
};
use crate::{
diagnostic::{DiagnosticConcreteArgs, DiagnosticDef, DiagnosticDefArgs},
utils::forward_to_single_field_variant,
};
pub struct Severity(pub syn::Ident);
impl Parse for Severity {
fn parse(input: ParseStream) -> syn::Result<Self> {
let ident = input.parse::<syn::Ident>()?;
if ident == "severity" {
let la = input.lookahead1();
if la.peek(syn::token::Paren) {
let content;
parenthesized!(content in input);
let la = content.lookahead1();
if la.peek(syn::LitStr) {
let str = content.parse::<syn::LitStr>()?;
let sev = get_severity(&str.value(), str.span())?;
Ok(Severity(syn::Ident::new(&sev, str.span())))
} else {
let ident = content.parse::<syn::Ident>()?;
let sev = get_severity(&ident.to_string(), ident.span())?;
Ok(Severity(syn::Ident::new(&sev, ident.span())))
}
} else {
input.parse::<Token![=]>()?;
let str = input.parse::<syn::LitStr>()?;
let sev = get_severity(&str.value(), str.span())?;
Ok(Severity(syn::Ident::new(&sev, str.span())))
}
} else {
Err(syn::Error::new(
ident.span(),
"MIETTE BUG: not a severity option",
))
}
}
}
fn get_severity(input: &str, span: Span) -> syn::Result<String> {
match input.to_lowercase().as_ref() {
"error" | "err" => Ok("Error".into()),
"warning" | "warn" => Ok("Warning".into()),
"advice" | "adv" | "info" => Ok("Advice".into()),
_ => Err(syn::Error::new(
span,
"Invalid severity level. Only Error, Warning, and Advice are supported.",
)),
}
}
impl Severity {
pub(crate) fn gen_enum(variants: &[DiagnosticDef]) -> Option<TokenStream> {
let sev_pairs = variants
.iter()
.map(
|DiagnosticDef {
ident, fields, args
}| {
match args {
DiagnosticDefArgs::Transparent => {
Some(forward_to_single_field_variant(ident, fields, quote!{ severity() }))
}
DiagnosticDefArgs::Concrete(DiagnosticConcreteArgs { severity, .. }) => {
let severity = &severity.as_ref()?.0;
let fields = match fields {
syn::Fields::Named(_) => quote! { { .. } },
syn::Fields::Unnamed(_) => quote! { (..) },
syn::Fields::Unit => quote!{},
};
Some(quote! { Self::#ident #fields => std::option::Option::Some(miette::Severity::#severity), })
}
}
},
)
.flatten()
.collect::<Vec<_>>();
if sev_pairs.is_empty() {
None
} else {
Some(quote! {
fn severity(&self) -> std::option::Option<miette::Severity> {
match self {
#(#sev_pairs)*
_ => std::option::Option::None,
}
}
})
}
}
pub(crate) fn gen_struct(&self) -> Option<TokenStream> {
let sev = &self.0;
Some(quote! {
fn severity(&self) -> std::option::Option<miette::Severity> {
Some(miette::Severity::#sev)
}
})
}
}