From 0388d9858627693bab2433f134eb4ed1d6e9b164 Mon Sep 17 00:00:00 2001 From: Nadrieril Date: Fri, 6 Sep 2019 18:17:36 +0200 Subject: Make ParseInput independent from dhall-specific types --- dhall_proc_macros/src/make_parser.rs | 8 ++++---- dhall_proc_macros/src/parse_children.rs | 6 +++--- 2 files changed, 7 insertions(+), 7 deletions(-) (limited to 'dhall_proc_macros') diff --git a/dhall_proc_macros/src/make_parser.rs b/dhall_proc_macros/src/make_parser.rs index a17ab61..c0594a5 100644 --- a/dhall_proc_macros/src/make_parser.rs +++ b/dhall_proc_macros/src/make_parser.rs @@ -179,7 +179,7 @@ fn apply_special_attrs(f: &mut ParsedFn, rule_enum: &Ident) -> Result<()> { #function #climber.climb( - #input_arg.pair.clone().into_inner(), + #input_arg.as_pair().clone().into_inner(), |p| Self::#child_rule(#input_arg.with_pair(p)), |l, op, r| { #fn_name(#input_arg.clone(), l?, op, r?) @@ -207,9 +207,9 @@ fn apply_special_attrs(f: &mut ParsedFn, rule_enum: &Ident) -> Result<()> { let mut #input_arg = #input_arg; // While the current rule allows shortcutting, and there is a single child, and the // child can still be parsed by the current function, then skip to that child. - while ::allows_shortcut(#input_arg.as_rule()) { + while ::allows_shortcut(#input_arg.as_rule()) { if let Some(child) = #input_arg.single_child() { - if &::rule_alias(child.as_rule()) + if &::rule_alias(child.as_rule()) == stringify!(#fn_name) { #input_arg = child; continue; @@ -313,7 +313,7 @@ pub fn make_parser( 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 { + impl #impl_generics pest_consume::PestConsumer for #ty #where_clause { type Rule = #rule_enum; fn rule_alias(rule: Self::Rule) -> String { match rule { diff --git a/dhall_proc_macros/src/parse_children.rs b/dhall_proc_macros/src/parse_children.rs index a35c03f..d6474a7 100644 --- a/dhall_proc_macros/src/parse_children.rs +++ b/dhall_proc_macros/src/parse_children.rs @@ -186,11 +186,11 @@ pub fn parse_children( .collect::>>()?; Ok(quote!({ - let #i_children_rules: Vec<_> = #input_expr.pair + let #i_children_rules: Vec<_> = #input_expr.as_pair() .clone() .into_inner() .map(|p| p.as_rule()) - .map(::rule_alias) + .map(::rule_alias) .collect(); let #i_children_rules: Vec<&str> = #i_children_rules .iter() @@ -199,7 +199,7 @@ pub fn parse_children( #[allow(unused_mut)] let mut #i_inputs = #input_expr - .pair + .as_pair() .clone() .into_inner() .map(|p| #input_expr.with_pair(p)); -- cgit v1.2.3 From accaf45aa77099654f94319ed1fb12855dd568b4 Mon Sep 17 00:00:00 2001 From: Nadrieril Date: Mon, 9 Sep 2019 22:42:46 +0200 Subject: Move pest_consume macros into their own crate --- dhall_proc_macros/src/lib.rs | 19 -- dhall_proc_macros/src/make_parser.rs | 334 -------------------------------- dhall_proc_macros/src/parse_children.rs | 215 -------------------- 3 files changed, 568 deletions(-) delete mode 100644 dhall_proc_macros/src/make_parser.rs delete mode 100644 dhall_proc_macros/src/parse_children.rs (limited to 'dhall_proc_macros') diff --git a/dhall_proc_macros/src/lib.rs b/dhall_proc_macros/src/lib.rs index 37e8f9f..5304429 100644 --- a/dhall_proc_macros/src/lib.rs +++ b/dhall_proc_macros/src/lib.rs @@ -1,4 +1,3 @@ -#![feature(drain_filter)] //! This crate contains the code-generation primitives for the [dhall-rust][dhall-rust] crate. //! This is highly unstable and breaks regularly; use at your own risk. //! @@ -7,8 +6,6 @@ extern crate proc_macro; mod derive; -mod make_parser; -mod parse_children; use proc_macro::TokenStream; @@ -16,19 +13,3 @@ use proc_macro::TokenStream; pub fn derive_static_type(input: TokenStream) -> TokenStream { derive::derive_static_type(input) } - -#[proc_macro_attribute] -pub fn make_parser(attrs: TokenStream, input: TokenStream) -> TokenStream { - TokenStream::from(match make_parser::make_parser(attrs, input) { - Ok(tokens) => tokens, - Err(err) => err.to_compile_error(), - }) -} - -#[proc_macro] -pub fn parse_children(input: TokenStream) -> TokenStream { - 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 deleted file mode 100644 index c0594a5..0000000 --- a/dhall_proc_macros/src/make_parser.rs +++ /dev/null @@ -1,334 +0,0 @@ -use std::collections::HashMap; -use std::iter; - -use quote::quote; -use syn::parse::{Parse, ParseStream, Result}; -use syn::spanned::Spanned; -use syn::{ - parse_quote, Error, Expr, FnArg, Ident, ImplItem, ImplItemMethod, ItemImpl, - LitBool, Pat, Token, -}; - -mod kw { - syn::custom_keyword!(shortcut); -} - -struct AliasArgs { - target: Ident, - is_shortcut: bool, -} - -struct PrecClimbArgs { - child_rule: Ident, - climber: Expr, -} - -struct AliasSrc { - ident: Ident, - is_shortcut: bool, -} - -struct ParsedFn<'a> { - // Body of the function - function: &'a mut ImplItemMethod, - // Name of the function. - fn_name: Ident, - // Name of the first argument of the function, which should be of type `ParseInput`. - input_arg: Ident, - // List of aliases pointing to this function - alias_srcs: Vec, -} - -impl Parse for AliasArgs { - fn parse(input: ParseStream) -> Result { - let target = input.parse()?; - let is_shortcut = if input.peek(Token![,]) { - // #[alias(rule, shortcut = true)] - let _: Token![,] = input.parse()?; - let _: kw::shortcut = input.parse()?; - let _: Token![=] = input.parse()?; - let b: LitBool = input.parse()?; - b.value - } else { - // #[alias(rule)] - false - }; - Ok(AliasArgs { - target, - is_shortcut, - }) - } -} - -impl Parse for PrecClimbArgs { - fn parse(input: ParseStream) -> Result { - let child_rule = input.parse()?; - let _: Token![,] = input.parse()?; - let climber = input.parse()?; - Ok(PrecClimbArgs { - child_rule, - climber, - }) - } -} - -fn collect_aliases( - imp: &mut ItemImpl, -) -> Result>> { - let functions = imp.items.iter_mut().flat_map(|item| match item { - ImplItem::Method(m) => Some(m), - _ => None, - }); - - let mut alias_map = HashMap::new(); - for function in functions { - let fn_name = function.sig.ident.clone(); - let mut alias_attrs = function - .attrs - .drain_filter(|attr| attr.path.is_ident("alias")) - .collect::>() - .into_iter(); - - if let Some(attr) = alias_attrs.next() { - let args: AliasArgs = attr.parse_args()?; - alias_map.entry(args.target).or_insert_with(Vec::new).push( - AliasSrc { - ident: fn_name, - is_shortcut: args.is_shortcut, - }, - ); - } - if let Some(attr) = alias_attrs.next() { - return Err(Error::new( - attr.span(), - "expected at most one alias attribute", - )); - } - } - - Ok(alias_map) -} - -fn parse_fn<'a>( - function: &'a mut ImplItemMethod, - alias_map: &mut HashMap>, -) -> Result> { - let fn_name = function.sig.ident.clone(); - // Get the name of the first (`input`) function argument - let input_arg = function.sig.inputs.first().ok_or_else(|| { - Error::new( - function.sig.inputs.span(), - "a rule function needs an `input` argument", - ) - })?; - let input_arg = match &input_arg { - FnArg::Receiver(_) => return Err(Error::new( - input_arg.span(), - "a rule function should not have a `self` argument", - )), - FnArg::Typed(input_arg) => match &*input_arg.pat{ - Pat::Ident(ident) => ident.ident.clone(), - _ => return Err(Error::new( - input_arg.span(), - "this argument should be a plain identifier instead of a pattern", - )), - } - }; - - let alias_srcs = alias_map.remove(&fn_name).unwrap_or_else(Vec::new); - - Ok(ParsedFn { - function, - fn_name, - input_arg, - alias_srcs, - }) -} - -fn apply_special_attrs(f: &mut ParsedFn, rule_enum: &Ident) -> Result<()> { - let function = &mut *f.function; - let fn_name = &f.fn_name; - let input_arg = &f.input_arg; - - *function = parse_quote!( - #[allow(non_snake_case)] - #function - ); - - // `prec_climb` attr - let prec_climb_attrs: Vec<_> = function - .attrs - .drain_filter(|attr| attr.path.is_ident("prec_climb")) - .collect(); - - if prec_climb_attrs.len() > 1 { - return Err(Error::new( - prec_climb_attrs[1].span(), - "expected at most one prec_climb attribute", - )); - } else if prec_climb_attrs.is_empty() { - // do nothing - } else { - let attr = prec_climb_attrs.into_iter().next().unwrap(); - let PrecClimbArgs { - child_rule, - climber, - } = attr.parse_args()?; - - function.block = parse_quote!({ - #function - - #climber.climb( - #input_arg.as_pair().clone().into_inner(), - |p| Self::#child_rule(#input_arg.with_pair(p)), - |l, op, r| { - #fn_name(#input_arg.clone(), l?, op, r?) - }, - ) - }); - // Remove the 3 last arguments to keep only the `input` one - function.sig.inputs.pop(); - function.sig.inputs.pop(); - function.sig.inputs.pop(); - // Check that an argument remains - function.sig.inputs.first().ok_or_else(|| { - Error::new( - function.sig.inputs.span(), - "a prec_climb function needs 4 arguments", - ) - })?; - } - - // `alias` attr - if !f.alias_srcs.is_empty() { - let aliases = f.alias_srcs.iter().map(|src| &src.ident); - let block = &function.block; - function.block = parse_quote!({ - let mut #input_arg = #input_arg; - // While the current rule allows shortcutting, and there is a single child, and the - // child can still be parsed by the current function, then skip to that child. - while ::allows_shortcut(#input_arg.as_rule()) { - if let Some(child) = #input_arg.single_child() { - if &::rule_alias(child.as_rule()) - == stringify!(#fn_name) { - #input_arg = child; - continue; - } - } - break - } - - match #input_arg.as_rule() { - #(#rule_enum::#aliases => Self::#aliases(#input_arg),)* - #rule_enum::#fn_name => #block, - r => unreachable!( - "make_parser: called {} on {:?}", - stringify!(#fn_name), - r - ) - } - }); - } - - Ok(()) -} - -pub fn make_parser( - attrs: proc_macro::TokenStream, - input: proc_macro::TokenStream, -) -> Result { - let rule_enum: Ident = syn::parse(attrs)?; - let mut imp: ItemImpl = syn::parse(input)?; - - let mut alias_map = collect_aliases(&mut imp)?; - let rule_alias_branches: Vec<_> = alias_map - .iter() - .flat_map(|(tgt, srcs)| iter::repeat(tgt).zip(srcs)) - .map(|(tgt, src)| { - let ident = &src.ident; - quote!( - #rule_enum::#ident => stringify!(#tgt).to_string(), - ) - }) - .collect(); - let shortcut_branches: Vec<_> = alias_map - .iter() - .flat_map(|(_tgt, srcs)| srcs) - .map(|AliasSrc { ident, is_shortcut }| { - quote!( - #rule_enum::#ident => #is_shortcut, - ) - }) - .collect(); - - let fn_map: HashMap = imp - .items - .iter_mut() - .flat_map(|item| match item { - ImplItem::Method(m) => Some(m), - _ => None, - }) - .map(|method| { - let mut f = parse_fn(method, &mut alias_map)?; - apply_special_attrs(&mut f, &rule_enum)?; - Ok((f.fn_name.clone(), f)) - }) - .collect::>()?; - - // Entries that remain in the alias map don't have a matching method, so we create one. - let extra_fns: Vec<_> = alias_map - .iter() - .map(|(tgt, srcs)| { - // Get the signature of one of the functions that has this alias. They should all have - // essentially the same signature anyways. - let f = fn_map.get(&srcs.first().unwrap().ident).unwrap(); - let input_arg = f.input_arg.clone(); - let mut sig = f.function.sig.clone(); - sig.ident = tgt.clone(); - let srcs = srcs.iter().map(|src| &src.ident); - - Ok(parse_quote!( - #sig { - match #input_arg.as_rule() { - #(#rule_enum::#srcs => Self::#srcs(#input_arg),)* - // We can't match on #rule_enum::#tgt since `tgt` might be an arbitrary - // identifier. - r if &format!("{:?}", r) == stringify!(#tgt) => - return Err(#input_arg.error(format!( - "make_parser: missing method for rule {}", - stringify!(#tgt), - ))), - r => unreachable!( - "make_parser: called {} on {:?}", - stringify!(#tgt), - r - ) - } - } - )) - }) - .collect::>()?; - imp.items.extend(extra_fns); - - let ty = &imp.self_ty; - let (impl_generics, _, where_clause) = imp.generics.split_for_impl(); - Ok(quote!( - impl #impl_generics pest_consume::PestConsumer for #ty #where_clause { - type Rule = #rule_enum; - fn rule_alias(rule: Self::Rule) -> String { - match rule { - #(#rule_alias_branches)* - r => format!("{:?}", r), - } - } - fn allows_shortcut(rule: Self::Rule) -> bool { - match rule { - #(#shortcut_branches)* - _ => false, - } - } - } - - #imp - )) -} diff --git a/dhall_proc_macros/src/parse_children.rs b/dhall_proc_macros/src/parse_children.rs deleted file mode 100644 index d6474a7..0000000 --- a/dhall_proc_macros/src/parse_children.rs +++ /dev/null @@ -1,215 +0,0 @@ -use proc_macro2::{Span, TokenStream}; -use quote::quote; -use syn::parse::{Parse, ParseStream, Result}; -use syn::punctuated::Punctuated; -use syn::spanned::Spanned; -use syn::{bracketed, parenthesized, token, Error, Expr, Ident, Pat, Token}; - -#[derive(Debug, Clone)] -struct ChildrenBranch { - pattern_span: Span, - pattern: Punctuated, - body: Expr, -} - -#[derive(Debug, Clone)] -enum ChildrenBranchPatternItem { - Single { rule_name: Ident, binder: Pat }, - Multiple { rule_name: Ident, binder: Ident }, -} - -#[derive(Debug, Clone)] -struct ParseChildrenInput { - input_expr: Expr, - branches: Punctuated, -} - -impl Parse for ChildrenBranch { - fn parse(input: ParseStream) -> Result { - let contents; - let _: token::Bracket = bracketed!(contents in input); - let pattern_unparsed: TokenStream = contents.fork().parse()?; - let pattern_span = pattern_unparsed.span(); - let pattern = Punctuated::parse_terminated(&contents)?; - let _: Token![=>] = input.parse()?; - let body = input.parse()?; - - Ok(ChildrenBranch { - pattern_span, - pattern, - body, - }) - } -} - -impl Parse for ChildrenBranchPatternItem { - fn parse(input: ParseStream) -> Result { - let contents; - let rule_name = input.parse()?; - parenthesized!(contents in input); - if input.peek(Token![..]) { - let binder = contents.parse()?; - let _: Token![..] = input.parse()?; - Ok(ChildrenBranchPatternItem::Multiple { rule_name, binder }) - } else if input.is_empty() || input.peek(Token![,]) { - let binder = contents.parse()?; - Ok(ChildrenBranchPatternItem::Single { rule_name, binder }) - } else { - Err(input.error("expected `..` or nothing")) - } - } -} - -impl Parse for ParseChildrenInput { - fn parse(input: ParseStream) -> Result { - let input_expr = input.parse()?; - let _: Token![;] = input.parse()?; - let branches = Punctuated::parse_terminated(input)?; - - Ok(ParseChildrenInput { - input_expr, - branches, - }) - } -} - -fn make_parser_branch( - branch: &ChildrenBranch, - i_inputs: &Ident, -) -> Result { - use ChildrenBranchPatternItem::{Multiple, Single}; - - let body = &branch.body; - - // Convert the input pattern into a pattern-match on the Rules of the children. This uses - // slice_patterns. - // A single pattern just checks that the rule matches; a variable-length pattern binds the - // subslice and checks, in the if-guard, that its elements all match the chosen Rule. - let i_variable_pattern = - Ident::new("___variable_pattern", Span::call_site()); - let match_pat = branch.pattern.iter().map(|item| match item { - Single { rule_name, .. } => quote!(stringify!(#rule_name)), - Multiple { .. } => quote!(#i_variable_pattern @ ..), - }); - let match_filter = branch.pattern.iter().map(|item| match item { - Single { .. } => quote!(), - Multiple { rule_name, .. } => quote!( - { - // We can't use .all() directly in the pattern guard; see - // https://github.com/rust-lang/rust/issues/59803. - let all_match = |slice: &[_]| { - slice.iter().all(|r| - *r == stringify!(#rule_name) - ) - }; - all_match(#i_variable_pattern) - } && - ), - }); - - // Once we have found a branch that matches, we need to parse the children. - let mut singles_before_multiple = Vec::new(); - let mut multiple = None; - let mut singles_after_multiple = Vec::new(); - for item in &branch.pattern { - match item { - Single { - rule_name, binder, .. - } => { - if multiple.is_none() { - singles_before_multiple.push((rule_name, binder)) - } else { - singles_after_multiple.push((rule_name, binder)) - } - } - Multiple { - rule_name, binder, .. - } => { - if multiple.is_none() { - multiple = Some((rule_name, binder)) - } else { - return Err(Error::new( - branch.pattern_span.clone(), - "multiple variable-length patterns are not allowed", - )); - } - } - } - } - let mut parses = Vec::new(); - for (rule_name, binder) in singles_before_multiple.into_iter() { - parses.push(quote!( - let #binder = Self::#rule_name( - #i_inputs.next().unwrap() - )?; - )) - } - // Note the `rev()`: we are taking inputs from the end of the iterator in reverse order, so that - // only the unmatched inputs are left for the variable-length pattern, if any. - for (rule_name, binder) in singles_after_multiple.into_iter().rev() { - parses.push(quote!( - let #binder = Self::#rule_name( - #i_inputs.next_back().unwrap() - )?; - )) - } - if let Some((rule_name, binder)) = multiple { - parses.push(quote!( - let #binder = #i_inputs - .map(|i| Self::#rule_name(i)) - .collect::, _>>()? - .into_iter(); - )) - } - - Ok(quote!( - [#(#match_pat),*] if #(#match_filter)* true => { - #(#parses)* - #body - } - )) -} - -pub fn parse_children( - input: proc_macro::TokenStream, -) -> Result { - let input: ParseChildrenInput = syn::parse(input)?; - - let i_children_rules = Ident::new("___children_rules", Span::call_site()); - let i_inputs = Ident::new("___inputs", Span::call_site()); - - let input_expr = &input.input_expr; - let branches = input - .branches - .iter() - .map(|br| make_parser_branch(br, &i_inputs)) - .collect::>>()?; - - Ok(quote!({ - let #i_children_rules: Vec<_> = #input_expr.as_pair() - .clone() - .into_inner() - .map(|p| p.as_rule()) - .map(::rule_alias) - .collect(); - let #i_children_rules: Vec<&str> = #i_children_rules - .iter() - .map(String::as_str) - .collect(); - - #[allow(unused_mut)] - let mut #i_inputs = #input_expr - .as_pair() - .clone() - .into_inner() - .map(|p| #input_expr.with_pair(p)); - - #[allow(unreachable_code)] - match #i_children_rules.as_slice() { - #(#branches,)* - [..] => return Err(#input_expr.error( - format!("Unexpected children: {:?}", #i_children_rules) - )), - } - })) -} -- cgit v1.2.3