diff options
Diffstat (limited to 'dhall_proc_macros')
-rw-r--r-- | dhall_proc_macros/src/lib.rs | 7 | ||||
-rw-r--r-- | dhall_proc_macros/src/make_parser.rs | 90 | ||||
-rw-r--r-- | dhall_proc_macros/src/parse_children.rs (renamed from dhall_proc_macros/src/parser.rs) | 88 |
3 files changed, 95 insertions, 90 deletions
diff --git a/dhall_proc_macros/src/lib.rs b/dhall_proc_macros/src/lib.rs index 63dd29a..37e8f9f 100644 --- a/dhall_proc_macros/src/lib.rs +++ b/dhall_proc_macros/src/lib.rs @@ -7,7 +7,8 @@ extern crate proc_macro; mod derive; -mod parser; +mod make_parser; +mod parse_children; use proc_macro::TokenStream; @@ -18,7 +19,7 @@ pub fn derive_static_type(input: TokenStream) -> TokenStream { #[proc_macro_attribute] pub fn make_parser(attrs: TokenStream, input: TokenStream) -> TokenStream { - TokenStream::from(match parser::make_parser(attrs, input) { + TokenStream::from(match make_parser::make_parser(attrs, input) { Ok(tokens) => tokens, Err(err) => err.to_compile_error(), }) @@ -26,7 +27,7 @@ pub fn make_parser(attrs: TokenStream, input: TokenStream) -> TokenStream { #[proc_macro] pub fn parse_children(input: TokenStream) -> TokenStream { - TokenStream::from(match parser::parse_children(input) { + TokenStream::from(match parse_children::parse_children(input) { Ok(tokens) => tokens, Err(err) => err.to_compile_error(), }) diff --git a/dhall_proc_macros/src/make_parser.rs b/dhall_proc_macros/src/make_parser.rs new file mode 100644 index 0000000..63ce779 --- /dev/null +++ b/dhall_proc_macros/src/make_parser.rs @@ -0,0 +1,90 @@ +use quote::quote; +use syn::parse::{ParseStream, Result}; +use syn::spanned::Spanned; +use syn::{ + parse_quote, Error, Expr, Ident, ImplItem, ImplItemMethod, ItemImpl, + ReturnType, Token, +}; + +fn apply_special_attrs( + rule_enum: &Ident, + function: &mut ImplItemMethod, +) -> Result<()> { + let recognized_attrs: Vec<_> = function + .attrs + .drain_filter(|attr| attr.path.is_ident("prec_climb")) + .collect(); + + let name = function.sig.ident.clone(); + let output_type = match &function.sig.output { + ReturnType::Default => parse_quote!(()), + ReturnType::Type(_, t) => (**t).clone(), + }; + + if recognized_attrs.is_empty() { + } else if recognized_attrs.len() > 1 { + return Err(Error::new( + recognized_attrs[1].span(), + "expected a single prec_climb attribute", + )); + } else { + let attr = recognized_attrs.into_iter().next().unwrap(); + let (child_rule, climber) = + attr.parse_args_with(|input: ParseStream| { + let child_rule: Ident = input.parse()?; + let _: Token![,] = input.parse()?; + let climber: Expr = input.parse()?; + Ok((child_rule, climber)) + })?; + + *function = parse_quote!( + fn #name<'a>( + input: ParseInput<'a, #rule_enum>, + ) -> #output_type { + #[allow(non_snake_case, dead_code)] + #function + + #climber.climb( + input.pair.clone().into_inner(), + |p| Self::#child_rule(input.with_pair(p)), + |l, op, r| { + #name(input.clone(), l?, op, r?) + }, + ) + } + ); + } + + *function = parse_quote!( + #[allow(non_snake_case, dead_code)] + #function + ); + + Ok(()) +} + +pub fn make_parser( + attrs: proc_macro::TokenStream, + input: proc_macro::TokenStream, +) -> Result<proc_macro2::TokenStream> { + let rule_enum: Ident = syn::parse(attrs)?; + + let mut imp: ItemImpl = syn::parse(input)?; + imp.items + .iter_mut() + .map(|item| match item { + ImplItem::Method(m) => apply_special_attrs(&rule_enum, m), + _ => Ok(()), + }) + .collect::<Result<()>>()?; + + let ty = &imp.self_ty; + let (impl_generics, _, where_clause) = imp.generics.split_for_impl(); + Ok(quote!( + impl #impl_generics PestConsumer for #ty #where_clause { + type RuleEnum = #rule_enum; + } + + #imp + )) +} diff --git a/dhall_proc_macros/src/parser.rs b/dhall_proc_macros/src/parse_children.rs index a440b16..ce6f66c 100644 --- a/dhall_proc_macros/src/parser.rs +++ b/dhall_proc_macros/src/parse_children.rs @@ -3,10 +3,7 @@ use quote::quote; use syn::parse::{Parse, ParseStream, Result}; use syn::punctuated::Punctuated; use syn::spanned::Spanned; -use syn::{ - bracketed, parenthesized, parse_quote, token, Error, Expr, Ident, ImplItem, - ImplItemMethod, ItemImpl, Pat, ReturnType, Token, -}; +use syn::{bracketed, parenthesized, token, Error, Expr, Ident, Pat, Token}; #[derive(Debug, Clone)] struct ChildrenBranch { @@ -76,89 +73,6 @@ impl Parse for ParseChildrenInput { } } -fn apply_special_attrs( - rule_enum: &Ident, - function: &mut ImplItemMethod, -) -> Result<()> { - let recognized_attrs: Vec<_> = function - .attrs - .drain_filter(|attr| attr.path.is_ident("prec_climb")) - .collect(); - - let name = function.sig.ident.clone(); - let output_type = match &function.sig.output { - ReturnType::Default => parse_quote!(()), - ReturnType::Type(_, t) => (**t).clone(), - }; - - if recognized_attrs.is_empty() { - } else if recognized_attrs.len() > 1 { - return Err(Error::new( - recognized_attrs[1].span(), - "expected a single prec_climb attribute", - )); - } else { - let attr = recognized_attrs.into_iter().next().unwrap(); - let (child_rule, climber) = - attr.parse_args_with(|input: ParseStream| { - let child_rule: Ident = input.parse()?; - let _: Token![,] = input.parse()?; - let climber: Expr = input.parse()?; - Ok((child_rule, climber)) - })?; - - *function = parse_quote!( - fn #name<'a>( - input: ParseInput<'a, #rule_enum>, - ) -> #output_type { - #[allow(non_snake_case, dead_code)] - #function - - #climber.climb( - input.pair.clone().into_inner(), - |p| Self::#child_rule(input.with_pair(p)), - |l, op, r| { - #name(input.clone(), l?, op, r?) - }, - ) - } - ); - } - - *function = parse_quote!( - #[allow(non_snake_case, dead_code)] - #function - ); - - Ok(()) -} - -pub fn make_parser( - attrs: proc_macro::TokenStream, - input: proc_macro::TokenStream, -) -> Result<proc_macro2::TokenStream> { - let rule_enum: Ident = syn::parse(attrs)?; - - let mut imp: ItemImpl = syn::parse(input)?; - imp.items - .iter_mut() - .map(|item| match item { - ImplItem::Method(m) => apply_special_attrs(&rule_enum, m), - _ => Ok(()), - }) - .collect::<Result<()>>()?; - - let ty = &imp.self_ty; - let (impl_generics, _, where_clause) = imp.generics.split_for_impl(); - Ok(quote!( - impl #impl_generics PestConsumer for #ty #where_clause { - type RuleEnum = #rule_enum; - } - - #imp - )) -} - fn make_parser_branch(branch: &ChildrenBranch) -> Result<TokenStream> { use ChildrenBranchPatternItem::{Multiple, Single}; |