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-rw-r--r--Cargo.lock13
-rw-r--r--Cargo.toml2
-rw-r--r--dhall_syntax/Cargo.toml3
-rw-r--r--dhall_syntax/src/parser.rs62
-rw-r--r--pest_consume/Cargo.toml15
-rw-r--r--pest_consume/examples/csv/csv.pest15
-rw-r--r--pest_consume/examples/csv/main.rs69
-rw-r--r--pest_consume/src/lib.rs325
-rw-r--r--pest_consume_macros/Cargo.toml19
-rw-r--r--pest_consume_macros/src/lib.rs27
-rw-r--r--pest_consume_macros/src/make_parser.rs424
-rw-r--r--pest_consume_macros/src/match_nodes.rs248
12 files changed, 36 insertions, 1186 deletions
diff --git a/Cargo.lock b/Cargo.lock
index 82212fe..5e81f7f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -116,8 +116,7 @@ dependencies = [
"lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
"percent-encoding 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
"pest 2.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "pest_consume 0.1.0",
- "pest_derive 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "pest_consume 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
"take_mut 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
]
@@ -240,17 +239,19 @@ dependencies = [
[[package]]
name = "pest_consume"
-version = "0.1.0"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"pest 2.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "pest_consume_macros 0.1.0",
+ "pest_consume_macros 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
"pest_derive 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
"proc-macro-hack 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "pest_consume_macros"
-version = "0.1.0"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"proc-macro-hack 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
"proc-macro2 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -522,6 +523,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
"checksum output_vt100 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "53cdc5b785b7a58c5aad8216b3dfa114df64b0b06ae6e1501cef91df2fbdf8f9"
"checksum percent-encoding 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d4fd5641d01c8f18a23da7b6fe29298ff4b55afcccdf78973b24cf3175fee32e"
"checksum pest 2.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7e4fb201c5c22a55d8b24fef95f78be52738e5e1361129be1b5e862ecdb6894a"
+"checksum pest_consume 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "db19e2b6df75694d2a73accd716c3e2b28d6241ad88ec140a5588eb4486eeb40"
+"checksum pest_consume_macros 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "36dc3a65f772c034446335f2a09fa4ea7a3cc471f130acdb06e96225f0ee6da0"
"checksum pest_derive 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "833d1ae558dc601e9a60366421196a8d94bc0ac980476d0b67e1d0988d72b2d0"
"checksum pest_generator 2.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7b9fcf299b5712d06ee128a556c94709aaa04512c4dffb8ead07c5c998447fc0"
"checksum pest_meta 2.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "df43fd99896fd72c485fe47542c7b500e4ac1e8700bf995544d1317a60ded547"
diff --git a/Cargo.toml b/Cargo.toml
index ec6a760..1e40748 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,8 +8,6 @@ members = [
"dhall_syntax",
"dhall_proc_macros",
"improved_slice_patterns",
- "pest_consume",
- "pest_consume_macros",
"serde_dhall"
]
diff --git a/dhall_syntax/Cargo.toml b/dhall_syntax/Cargo.toml
index 8d9cca6..b98c4a4 100644
--- a/dhall_syntax/Cargo.toml
+++ b/dhall_syntax/Cargo.toml
@@ -12,11 +12,10 @@ doctest = false
itertools = "0.8.0"
percent-encoding = "2.1.0"
pest = "2.1"
-pest_derive = "2.1"
either = "1.5.2"
take_mut = "0.2.2"
hex = "0.3.2"
lazy_static = "1.4.0"
dhall_generated_parser = { path = "../dhall_generated_parser" }
dhall_proc_macros = { path = "../dhall_proc_macros" }
-pest_consume = { path = "../pest_consume" }
+pest_consume = "1.0"
diff --git a/dhall_syntax/src/parser.rs b/dhall_syntax/src/parser.rs
index 2af2d92..71fab0f 100644
--- a/dhall_syntax/src/parser.rs
+++ b/dhall_syntax/src/parser.rs
@@ -1,5 +1,4 @@
use itertools::Itertools;
-use pest::iterators::Pair;
use pest::prec_climber as pcl;
use pest::prec_climber::PrecClimber;
use std::rc::Rc;
@@ -167,7 +166,7 @@ impl DhallParser {
fn double_quote_literal<E: Clone>(
input: ParseInput,
) -> ParseResult<ParsedText<E>> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[double_quote_chunk(chunks)..] => {
chunks.collect()
}
@@ -177,7 +176,7 @@ impl DhallParser {
fn double_quote_chunk<E: Clone>(
input: ParseInput,
) -> ParseResult<ParsedTextContents<E>> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[expression(e)] => {
InterpolatedTextContents::Expr(e)
},
@@ -264,7 +263,7 @@ impl DhallParser {
fn single_quote_literal<E: Clone>(
input: ParseInput,
) -> ParseResult<ParsedText<E>> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[single_quote_continue(lines)] => {
let newline: ParsedText<E> = "\n".to_string().into();
@@ -301,7 +300,7 @@ impl DhallParser {
fn single_quote_continue<E: Clone>(
input: ParseInput,
) -> ParseResult<Vec<Vec<ParsedTextContents<E>>>> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[expression(e), single_quote_continue(lines)] => {
let c = InterpolatedTextContents::Expr(e);
let mut lines = lines;
@@ -387,21 +386,15 @@ impl DhallParser {
#[alias(expression, shortcut = true)]
fn identifier<E: Clone>(input: ParseInput) -> ParseResult<Expr<E>> {
Ok(match_nodes!(input.children();
- [variable(v)] => {
- spanned(input, Var(v))
- },
+ [variable(v)] => spanned(input, Var(v)),
[expression(e)] => e,
))
}
fn variable(input: ParseInput) -> ParseResult<V<Label>> {
- Ok(match_nodes!(input.children();
- [label(l), natural_literal(idx)] => {
- V(l, idx)
- },
- [label(l)] => {
- V(l, 0)
- },
+ Ok(match_nodes!(input.into_children();
+ [label(l), natural_literal(idx)] => V(l, idx),
+ [label(l)] => V(l, 0),
))
}
@@ -437,7 +430,7 @@ impl DhallParser {
.collect())
}
fn path(input: ParseInput) -> ParseResult<Vec<String>> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[path_component(components)..] => {
components.collect()
}
@@ -448,7 +441,7 @@ impl DhallParser {
fn local<E: Clone>(
input: ParseInput,
) -> ParseResult<ImportLocation<Expr<E>>> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[local_path((prefix, p))] => ImportLocation::Local(prefix, p),
))
}
@@ -457,19 +450,19 @@ impl DhallParser {
fn parent_path(
input: ParseInput,
) -> ParseResult<(FilePrefix, Vec<String>)> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[path(p)] => (FilePrefix::Parent, p)
))
}
#[alias(local_path)]
fn here_path(input: ParseInput) -> ParseResult<(FilePrefix, Vec<String>)> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[path(p)] => (FilePrefix::Here, p)
))
}
#[alias(local_path)]
fn home_path(input: ParseInput) -> ParseResult<(FilePrefix, Vec<String>)> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[path(p)] => (FilePrefix::Home, p)
))
}
@@ -477,7 +470,7 @@ impl DhallParser {
fn absolute_path(
input: ParseInput,
) -> ParseResult<(FilePrefix, Vec<String>)> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[path(p)] => (FilePrefix::Absolute, p)
))
}
@@ -491,7 +484,7 @@ impl DhallParser {
}
fn http_raw<E: Clone>(input: ParseInput) -> ParseResult<URL<Expr<E>>> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[scheme(sch), authority(auth), path(p)] => URL {
scheme: sch,
authority: auth,
@@ -521,7 +514,7 @@ impl DhallParser {
fn http<E: Clone>(
input: ParseInput,
) -> ParseResult<ImportLocation<Expr<E>>> {
- Ok(ImportLocation::Remote(match_nodes!(input.children();
+ Ok(ImportLocation::Remote(match_nodes!(input.into_children();
[http_raw(url)] => url,
[http_raw(url), expression(e)] => URL { headers: Some(e), ..url },
)))
@@ -531,7 +524,7 @@ impl DhallParser {
fn env<E: Clone>(
input: ParseInput,
) -> ParseResult<ImportLocation<Expr<E>>> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[environment_variable(v)] => ImportLocation::Env(v),
))
}
@@ -541,7 +534,7 @@ impl DhallParser {
}
#[alias(environment_variable)]
fn posix_environment_variable(input: ParseInput) -> ParseResult<String> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[posix_environment_variable_character(chars)..] => {
chars.collect()
},
@@ -586,7 +579,7 @@ impl DhallParser {
) -> ParseResult<crate::Import<Expr<E>>> {
use crate::Import;
let mode = ImportMode::Code;
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[import_type(location)] => Import { mode, location, hash: None },
[import_type(location), hash(h)] => Import { mode, location, hash: Some(h) },
))
@@ -703,9 +696,8 @@ impl DhallParser {
#[alias(expression, shortcut = true)]
#[prec_climb(expression, PRECCLIMBER)]
fn operator_expression<E: Clone>(
- input: ParseInput,
l: Expr<E>,
- op: Pair<Rule>,
+ op: ParseInput,
r: Expr<E>,
) -> ParseResult<Expr<E>> {
use crate::BinOp::*;
@@ -724,7 +716,7 @@ impl DhallParser {
bool_eq => BoolEQ,
bool_ne => BoolNE,
equivalent => Equivalence,
- r => Err(input.error(format!("Rule {:?} isn't an operator", r)))?,
+ r => Err(op.error(format!("Rule {:?} isn't an operator", r)))?,
};
Ok(spanned_union(
@@ -812,7 +804,7 @@ impl DhallParser {
}
fn labels(input: ParseInput) -> ParseResult<DupTreeSet<Label>> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[label(ls)..] => ls.collect(),
))
}
@@ -865,7 +857,7 @@ impl DhallParser {
fn non_empty_record_type<E: Clone>(
input: ParseInput,
) -> ParseResult<(Expr<E>, DupTreeMap<Label, Expr<E>>)> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[expression(expr), record_type_entry(entries)..] => {
(expr, entries.collect())
}
@@ -875,7 +867,7 @@ impl DhallParser {
fn record_type_entry<E: Clone>(
input: ParseInput,
) -> ParseResult<(Label, Expr<E>)> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[label(name), expression(expr)] => (name, expr)
))
}
@@ -883,7 +875,7 @@ impl DhallParser {
fn non_empty_record_literal<E: Clone>(
input: ParseInput,
) -> ParseResult<(Expr<E>, DupTreeMap<Label, Expr<E>>)> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[expression(expr), record_literal_entry(entries)..] => {
(expr, entries.collect())
}
@@ -893,7 +885,7 @@ impl DhallParser {
fn record_literal_entry<E: Clone>(
input: ParseInput,
) -> ParseResult<(Label, Expr<E>)> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[label(name), expression(expr)] => (name, expr)
))
}
@@ -934,7 +926,7 @@ impl DhallParser {
#[alias(expression)]
fn final_expression<E: Clone>(input: ParseInput) -> ParseResult<Expr<E>> {
- Ok(match_nodes!(input.children();
+ Ok(match_nodes!(input.into_children();
[expression(e), EOI(_)] => e
))
}
diff --git a/pest_consume/Cargo.toml b/pest_consume/Cargo.toml
deleted file mode 100644
index 1b8ebf6..0000000
--- a/pest_consume/Cargo.toml
+++ /dev/null
@@ -1,15 +0,0 @@
-[package]
-name = "pest_consume"
-version = "0.1.0" # remember to update html_root_url
-authors = ["Nadrieril <nadrieril@users.noreply.github.com>"]
-license = "MIT OR Apache-2.0"
-edition = "2018"
-description = "A framework for processing the output of a pest-generated parser"
-readme = "README.md"
-repository = "https://github.com/Nadrieril/dhall-rust"
-
-[dependencies]
-pest = "2.1"
-pest_derive = "2.1"
-proc-macro-hack = "0.5.9"
-pest_consume_macros = { path = "../pest_consume_macros" }
diff --git a/pest_consume/examples/csv/csv.pest b/pest_consume/examples/csv/csv.pest
deleted file mode 100644
index a67af8c..0000000
--- a/pest_consume/examples/csv/csv.pest
+++ /dev/null
@@ -1,15 +0,0 @@
-WHITESPACE = _{ " "+ }
-newline = _{ "\r\n" | "\n" }
-number = { "-"? ~ (ASCII_DIGIT | ".")+ }
-string = { (!"'" ~ ASCII)* }
-field = ${
- number
- | "'" ~ string ~ "'"
-}
-record = {
- field ~ ("," ~ field)*
- | ""
-}
-file = {
- SOI ~ record ~ (newline ~ record)* ~ newline? ~ EOI
-}
diff --git a/pest_consume/examples/csv/main.rs b/pest_consume/examples/csv/main.rs
deleted file mode 100644
index 88621db..0000000
--- a/pest_consume/examples/csv/main.rs
+++ /dev/null
@@ -1,69 +0,0 @@
-use pest_consume::{match_nodes, Error, Parser};
-
-#[derive(Debug)]
-enum CSVField<'a> {
- Number(f64),
- String(&'a str),
-}
-type CSVRecord<'a> = Vec<CSVField<'a>>;
-type CSVFile<'a> = Vec<CSVRecord<'a>>;
-
-type Result<T> = std::result::Result<T, Error<Rule>>;
-type Node<'i> = pest_consume::Node<'i, Rule, ()>;
-
-#[derive(Parser)]
-#[grammar = "../examples/csv/csv.pest"]
-struct CSVParser;
-
-#[pest_consume::parser]
-impl CSVParser {
- fn EOI(_input: Node) -> Result<()> {
- Ok(())
- }
-
- fn number(input: Node) -> Result<f64> {
- input
- .as_str()
- .parse::<f64>()
- // `input.error` links the error to the location in the input file where it occurred.
- .map_err(|e| input.error(e.to_string()))
- }
-
- fn string(input: Node) -> Result<&str> {
- Ok(input.as_str())
- }
-
- fn field(input: Node) -> Result<CSVField> {
- Ok(match_nodes!(input.children();
- [number(n)] => CSVField::Number(n),
- [string(s)] => CSVField::String(s),
- ))
- }
-
- fn record(input: Node) -> Result<CSVRecord> {
- Ok(match_nodes!(input.children();
- [field(fields)..] => fields.collect(),
- ))
- }
-
- fn file(input: Node) -> Result<CSVFile> {
- Ok(match_nodes!(input.children();
- [record(records).., EOI(_)] => records.collect(),
- ))
- }
-}
-
-fn parse_csv(input_str: &str) -> Result<CSVFile> {
- let inputs = CSVParser::parse(Rule::file, input_str)?;
- Ok(match_nodes!(<CSVParser>; inputs;
- [file(e)] => e,
- ))
-}
-
-fn main() {
- let successful_parse = parse_csv("-273.15, ' a string '\n\n42, 0");
- println!("success: {:?}", successful_parse.unwrap());
-
- let unsuccessful_parse = parse_csv("0, 273.15.12");
- println!("failure: {}", unsuccessful_parse.unwrap_err());
-}
diff --git a/pest_consume/src/lib.rs b/pest_consume/src/lib.rs
deleted file mode 100644
index c1d62e5..0000000
--- a/pest_consume/src/lib.rs
+++ /dev/null
@@ -1,325 +0,0 @@
-//! `pest_consume` extends [pest] to make it easy to consume a pest parse tree.
-//! Given a grammar file, pest generates a parser that outputs an untyped parse tree. Then that
-//! parse tree needs to be transformed into whatever datastructures your application uses.
-//! `pest_consume` provides two macros to make this easy.
-//!
-//! Features of `pest_consume` include:
-//! - strong types;
-//! - consuming children uses an intuitive syntax;
-//! - error handling is well integrated.
-//!
-//! # Example
-//!
-//! Here is the [CSV example from the doc](https://pest.rs/book/examples/csv.html),
-//! using `pest_consume`.
-//!
-//! The pest grammar file contains:
-//! ```text
-//! field = { (ASCII_DIGIT | "." | "-")+ }
-//! record = { field ~ ("," ~ field)* }
-//! file = { SOI ~ (record ~ ("\r\n" | "\n"))* ~ EOI }
-//! ```
-//!
-//! ```no_run
-//! use pest_consume::{match_nodes, Error, Parser};
-//!
-//! type Result<T> = std::result::Result<T, Error<Rule>>;
-//! type Node<'i> = pest_consume::Node<'i, Rule, ()>;
-//!
-//! // Construct the first half of the parser using pest as usual.
-//! #[derive(Parser)]
-//! #[grammar = "../examples/csv/csv.pest"]
-//! struct CSVParser;
-//!
-//! // This is the other half of the parser, using pest_consume.
-//! #[pest_consume::parser]
-//! impl CSVParser {
-//! fn EOI(_input: Node) -> Result<()> {
-//! Ok(())
-//! }
-//! fn field(input: Node) -> Result<f64> {
-//! input
-//! .as_str()
-//! .parse::<f64>()
-//! .map_err(|e| input.error(e.to_string()))
-//! }
-//! fn record(input: Node) -> Result<Vec<f64>> {
-//! Ok(match_nodes!(input.children();
-//! [field(fields)..] => fields.collect(),
-//! ))
-//! }
-//! fn file(input: Node) -> Result<Vec<Vec<f64>>> {
-//! Ok(match_nodes!(input.children();
-//! [record(records).., EOI(_)] => records.collect(),
-//! ))
-//! }
-//! }
-//!
-//! fn parse_csv(input_str: &str) -> Result<Vec<Vec<f64>>> {
-//! let inputs = CSVParser::parse(Rule::file, input_str)?;
-//! Ok(match_nodes!(<CSVParser>; inputs;
-//! [file(e)] => e,
-//! ))
-//! }
-//!
-//! fn main() {
-//! let parsed = parse_csv("-273.15, 12\n42, 0").unwrap();
-//! let mut sum = 0.;
-//! for record in parsed {
-//! for field in record {
-//! sum += field;
-//! }
-//! }
-//! println!("{}", sum);
-//! }
-//! ```
-//!
-//! There are several things to note:
-//! - we use two macros provided by `pest_consume`: `parser` and `match_nodes`;
-//! - there is one `fn` item per (non-silent) rule in the grammar;
-//! - we associate an output type to every rule;
-//! - there is no need to fiddle with `.into_inner()`, `.next()` or `.unwrap()`, as is common when using pest
-//!
-//! # How it works
-//!
-//! The main types of this crate ([Node], [Nodes] and [Parser]) are mostly wrappers around
-//! the corresponding [pest] types.
-//!
-//! The `pest_consume::parser` macro does almost nothing when not using advanced features;
-//! most of the magic happens in `match_nodes`.
-//! `match_nodes` desugars rather straightforwardly into calls to the `fn` items corresponding to
-//! the rules matched on.
-//! For example:
-//! ```ignore
-//! match_nodes!(input.children();
-//! [field(fields)..] => fields.collect(),
-//! )
-//! ```
-//! desugars into:
-//! ```ignore
-//! let nodes = { input.children() };
-//! if ... { // check that all rules in `nodes` are the `field` rule
-//! let fields = nodes
-//! .map(|node| Self::field(node)) // Recursively parse children nodes
-//! ... // Propagate errors
-//! { fields.collect() }
-//! } else {
-//! ... // error because we got unexpected rules
-//! }
-//! ```
-//!
-//! # Advanced features
-//!
-//! TODO
-//!
-//! - rule aliasing
-//! - rule shortcutting
-//! - user data
-
-pub use pest::error::Error;
-use pest::Parser as PestParser;
-use pest::RuleType;
-pub use pest_derive::Parser;
-
-#[proc_macro_hack::proc_macro_hack]
-pub use pest_consume_macros::match_nodes;
-pub use pest_consume_macros::parser;
-
-mod node {
- use super::Parser;
- use pest::error::{Error, ErrorVariant};
- use pest::iterators::{Pair, Pairs};
- use pest::Parser as PestParser;
- use pest::{RuleType, Span};
-
- /// Carries a pest Pair alongside custom user data.
- #[derive(Debug, Clone)]
- pub struct Node<'input, Rule: RuleType, Data> {
- pair: Pair<'input, Rule>,
- user_data: Data,
- }
-
- /// Iterator over `Node`s. It is created by `Node::children` or `Nodes::new`.
- #[derive(Debug, Clone)]
- pub struct Nodes<'input, Rule: RuleType, Data> {
- pairs: Pairs<'input, Rule>,
- span: Span<'input>,
- user_data: Data,
- }
-
- impl<'i, R: RuleType, D> Node<'i, R, D> {
- pub fn new(pair: Pair<'i, R>, user_data: D) -> Self {
- Node { pair, user_data }
- }
- /// Create an error that points to the span of the input.
- pub fn error(&self, message: String) -> Error<R> {
- Error::new_from_span(
- ErrorVariant::CustomError { message },
- self.as_span(),
- )
- }
- /// Reconstruct the input with a new pair, passing the user data along.
- pub fn with_pair(&self, new_pair: Pair<'i, R>) -> Self
- where
- D: Clone,
- {
- Node {
- pair: new_pair,
- user_data: self.user_data.clone(),
- }
- }
- /// If the contained pair has exactly one child, return a new Self containing it.
- pub fn single_child(&self) -> Option<Self>
- where
- D: Clone,
- {
- let mut children = self.pair.clone().into_inner();
- if let Some(child) = children.next() {
- if children.next().is_none() {
- return Some(self.with_pair(child));
- }
- }
- None
- }
- /// Return an iterator over the children of this input
- // Can't use `-> impl Iterator` because of weird lifetime limitations
- // (see https://github.com/rust-lang/rust/issues/61997).
- pub fn children(&self) -> Nodes<'i, R, D>
- where
- D: Clone,
- {
- Nodes {
- pairs: self.as_pair().clone().into_inner(),
- span: self.as_span(),
- user_data: self.user_data(),
- }
- }
-
- pub fn user_data(&self) -> D
- where
- D: Clone,
- {
- self.user_data.clone()
- }
- pub fn as_pair(&self) -> &Pair<'i, R> {
- &self.pair
- }
- pub fn into_pair(self) -> Pair<'i, R> {
- self.pair
- }
- pub fn as_span(&self) -> Span<'i> {
- self.pair.as_span()
- }
- pub fn as_str(&self) -> &'i str {
- self.pair.as_str()
- }
- pub fn as_rule(&self) -> R {
- self.pair.as_rule()
- }
- pub fn as_aliased_rule<C>(&self) -> C::AliasedRule
- where
- C: Parser<Rule = R>,
- <C as Parser>::Parser: PestParser<R>,
- {
- C::rule_alias(self.as_rule())
- }
- }
-
- impl<'i, R: RuleType, D> Nodes<'i, R, D> {
- /// `input` must be the _original_ input that `pairs` is pointing to.
- pub fn new(input: &'i str, pairs: Pairs<'i, R>, user_data: D) -> Self {
- let span = Span::new(input, 0, input.len()).unwrap();
- Nodes {
- pairs,
- span,
- user_data,
- }
- }
- /// Create an error that points to the span of the input.
- pub fn error(&self, message: String) -> Error<R> {
- Error::new_from_span(
- ErrorVariant::CustomError { message },
- self.span.clone(),
- )
- }
- pub fn aliased_rules<C>(&self) -> Vec<C::AliasedRule>
- where
- D: Clone,
- C: Parser<Rule = R>,
- <C as Parser>::Parser: PestParser<R>,
- {
- self.clone().map(|p| p.as_aliased_rule::<C>()).collect()
- }
- /// Reconstruct the input with a new pair, passing the user data along.
- fn with_pair(&self, new_pair: Pair<'i, R>) -> Node<'i, R, D>
- where
- D: Clone,
- {
- Node::new(new_pair, self.user_data.clone())
- }
-
- pub fn as_pairs(&self) -> &Pairs<'i, R> {
- &self.pairs
- }
- pub fn into_pairs(self) -> Pairs<'i, R> {
- self.pairs
- }
- }
-
- impl<'i, R, D> Iterator for Nodes<'i, R, D>
- where
- R: RuleType,
- D: Clone,
- {
- type Item = Node<'i, R, D>;
-
- fn next(&mut self) -> Option<Self::Item> {
- let child_pair = self.pairs.next()?;
- let child = self.with_pair(child_pair);
- Some(child)
- }
- }
-
- impl<'i, R, D> DoubleEndedIterator for Nodes<'i, R, D>
- where
- R: RuleType,
- D: Clone,
- {
- fn next_back(&mut self) -> Option<Self::Item> {
- let child_pair = self.pairs.next_back()?;
- let child = self.with_pair(child_pair);
- Some(child)
- }
- }
-}
-
-pub use node::{Node, Nodes};
-
-/// Used by the macros.
-/// Do not implement manually.
-pub trait Parser {
- type Rule: RuleType;
- type AliasedRule: RuleType;
- type Parser: PestParser<Self::Rule>;
-
- fn rule_alias(rule: Self::Rule) -> Self::AliasedRule;
- fn allows_shortcut(rule: Self::Rule) -> bool;
-
- /// Parses a `&str` starting from `rule`
- fn parse<'i>(
- rule: Self::Rule,
- input_str: &'i str,
- ) -> Result<Nodes<'i, Self::Rule, ()>, Error<Self::Rule>> {
- Self::parse_with_userdata(rule, input_str, ())
- }
-
- /// Parses a `&str` starting from `rule`, carrying `user_data` through the parser methods.
- fn parse_with_userdata<'i, D>(
- rule: Self::Rule,
- input_str: &'i str,
- user_data: D,
- ) -> Result<Nodes<'i, Self::Rule, D>, Error<Self::Rule>> {
- let pairs = Self::Parser::parse(rule, input_str)?;
- Ok(Nodes::new(input_str, pairs, user_data))
- }
-}
diff --git a/pest_consume_macros/Cargo.toml b/pest_consume_macros/Cargo.toml
deleted file mode 100644
index aaa0b10..0000000
--- a/pest_consume_macros/Cargo.toml
+++ /dev/null
@@ -1,19 +0,0 @@
-[package]
-name = "pest_consume_macros"
-version = "0.1.0" # remember to update html_root_url
-authors = ["Nadrieril <nadrieril@users.noreply.github.com>"]
-license = "MIT OR Apache-2.0"
-edition = "2018"
-description = "Macros for pest_consume"
-readme = "README.md"
-repository = "https://github.com/Nadrieril/dhall-rust"
-
-[lib]
-proc-macro = true
-doctest = false
-
-[dependencies]
-quote = "1.0.2"
-proc-macro2 = "1.0.2"
-proc-macro-hack = "0.5.9"
-syn = { version = "1.0.5", features = ["full"] }
diff --git a/pest_consume_macros/src/lib.rs b/pest_consume_macros/src/lib.rs
deleted file mode 100644
index d726b5d..0000000
--- a/pest_consume_macros/src/lib.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-//! 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.
-//!
-//! [dhall-rust]: https://github.com/Nadrieril/dhall-rust
-
-extern crate proc_macro;
-
-mod make_parser;
-mod match_nodes;
-
-use proc_macro::TokenStream;
-
-#[proc_macro_attribute]
-pub fn 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_hack::proc_macro_hack]
-pub fn match_nodes(input: TokenStream) -> TokenStream {
- TokenStream::from(match match_nodes::match_nodes(input) {
- Ok(tokens) => tokens,
- Err(err) => err.to_compile_error(),
- })
-}
diff --git a/pest_consume_macros/src/make_parser.rs b/pest_consume_macros/src/make_parser.rs
deleted file mode 100644
index 5bf8fe3..0000000
--- a/pest_consume_macros/src/make_parser.rs
+++ /dev/null
@@ -1,424 +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, Path, Token,
-};
-
-/// Ext. trait adding `partition_filter` to `Vec`. Would like to use `Vec::drain_filter`
-/// but it's unstable for now.
-pub trait VecPartitionFilterExt<Item> {
- fn partition_filter<F>(&mut self, predicate: F) -> Vec<Item>
- where
- F: FnMut(&mut Item) -> bool;
-}
-
-impl<Item> VecPartitionFilterExt<Item> for Vec<Item> {
- fn partition_filter<F>(&mut self, mut predicate: F) -> Vec<Item>
- where
- F: FnMut(&mut Item) -> bool,
- {
- let mut ret = Vec::new();
- let mut i = 0;
- while i != self.len() {
- if predicate(&mut self[i]) {
- ret.push(self.remove(i))
- } else {
- i += 1;
- }
- }
- ret
- }
-}
-
-mod kw {
- syn::custom_keyword!(shortcut);
- syn::custom_keyword!(rule);
- syn::custom_keyword!(parser);
-}
-
-struct MakeParserAttrs {
- parser: Path,
- rule_enum: Path,
-}
-
-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 `Node`.
- input_arg: Ident,
- // List of aliases pointing to this function
- alias_srcs: Vec<AliasSrc>,
-}
-
-impl Parse for MakeParserAttrs {
- fn parse(input: ParseStream) -> Result<Self> {
- // By default, the pest parser is the same type as the pest_consume one
- let mut parser = parse_quote!(Self);
- // By default, use the `Rule` type in scope
- let mut rule_enum = parse_quote!(Rule);
-
- while !input.is_empty() {
- let lookahead = input.lookahead1();
- if lookahead.peek(kw::parser) {
- let _: kw::parser = input.parse()?;
- let _: Token![=] = input.parse()?;
- parser = input.parse()?;
- } else if lookahead.peek(kw::rule) {
- let _: kw::rule = input.parse()?;
- let _: Token![=] = input.parse()?;
- rule_enum = input.parse()?;
- } else {
- return Err(lookahead.error());
- }
-
- if input.peek(Token![,]) {
- let _: Token![,] = input.parse()?;
- } else {
- break;
- }
- }
-
- Ok(MakeParserAttrs { parser, rule_enum })
- }
-}
-
-impl Parse for AliasArgs {
- fn parse(input: ParseStream) -> Result<Self> {
- 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<Self> {
- 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<HashMap<Ident, Vec<AliasSrc>>> {
- 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
- .partition_filter(|attr| attr.path.is_ident("alias"))
- .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,
- },
- );
- } else {
- // Self entry
- alias_map
- .entry(fn_name.clone())
- .or_insert_with(Vec::new)
- .push(AliasSrc {
- ident: fn_name,
- is_shortcut: false,
- });
- }
- 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<Ident, Vec<AliasSrc>>,
-) -> Result<ParsedFn<'a>> {
- 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: &Path) -> 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
- .partition_filter(|attr| attr.path.is_ident("prec_climb"));
-
- 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
- // f.alias_srcs has always at least 1 element because it has an entry pointing from itself.
- if f.alias_srcs.len() > 1 {
- let aliases = f
- .alias_srcs
- .iter()
- .map(|src| &src.ident)
- .filter(|i| i != &fn_name);
- let block = &function.block;
- let self_ty = quote!(<Self as ::pest_consume::Parser>);
- 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 #self_ty::allows_shortcut(#input_arg.as_rule()) {
- if let ::std::option::Option::Some(child) = #input_arg.single_child() {
- if child.as_aliased_rule::<Self>() == #self_ty::AliasedRule::#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 => ::std::unreachable!(
- "make_parser: called {} on {:?}",
- ::std::stringify!(#fn_name),
- r
- )
- }
- });
- }
-
- Ok(())
-}
-
-pub fn make_parser(
- attrs: proc_macro::TokenStream,
- input: proc_macro::TokenStream,
-) -> Result<proc_macro2::TokenStream> {
- let attrs: MakeParserAttrs = syn::parse(attrs)?;
- let parser = &attrs.parser;
- let rule_enum = &attrs.rule_enum;
- 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 => Self::AliasedRule::#tgt,
- )
- })
- .collect();
- let aliased_rule_variants: Vec<_> =
- alias_map.iter().map(|(tgt, _)| tgt.clone()).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<Ident, ParsedFn> = 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::<Result<_>>()?;
-
- // 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 &::std::format!("{:?}", r) == ::std::stringify!(#tgt) =>
- return ::std::result::Result::Err(#input_arg.error(::std::format!(
- "make_parser: missing method for rule {}",
- ::std::stringify!(#tgt),
- ))),
- r => ::std::unreachable!(
- "make_parser: called {} on {:?}",
- ::std::stringify!(#tgt),
- r
- )
- }
- }
- ))
- })
- .collect::<Result<_>>()?;
- imp.items.extend(extra_fns);
-
- let ty = &imp.self_ty;
- let (impl_generics, _, where_clause) = imp.generics.split_for_impl();
- Ok(quote!(
- #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
- #[allow(non_camel_case_types)]
- enum AliasedRule {
- #(#aliased_rule_variants,)*
- }
-
- impl #impl_generics ::pest_consume::Parser for #ty #where_clause {
- type Rule = #rule_enum;
- type AliasedRule = AliasedRule;
- type Parser = #parser;
- fn rule_alias(rule: Self::Rule) -> Self::AliasedRule {
- match rule {
- #(#rule_alias_branches)*
- // TODO: return a proper error ?
- r => ::std::unreachable!("Rule {:?} does not have a corresponding parsing method", r),
- }
- }
- fn allows_shortcut(rule: Self::Rule) -> bool {
- match rule {
- #(#shortcut_branches)*
- _ => false,
- }
- }
- }
-
- #imp
- ))
-}
diff --git a/pest_consume_macros/src/match_nodes.rs b/pest_consume_macros/src/match_nodes.rs
deleted file mode 100644
index a91d1f4..0000000
--- a/pest_consume_macros/src/match_nodes.rs
+++ /dev/null
@@ -1,248 +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, parse_quote, token, Error, Expr, Ident, Pat,
- Token, Type,
-};
-
-#[derive(Clone)]
-struct MatchBranch {
- // Patterns all have the form [a, b, c.., d], with a bunch of simple patterns,
- // optionally a multiple pattern, and then some more simple patterns.
- singles_before_multiple: Vec<(Ident, Pat)>,
- multiple: Option<(Ident, Ident)>,
- singles_after_multiple: Vec<(Ident, Pat)>,
-
- body: Expr,
-}
-
-#[derive(Clone)]
-enum MatchBranchPatternItem {
- Single {
- rule_name: Ident,
- binder: Pat,
- },
- Multiple {
- rule_name: Ident,
- binder: Ident,
- slice_token: Token![..],
- },
-}
-
-#[derive(Clone)]
-struct MacroInput {
- parser: Type,
- input_expr: Expr,
- branches: Punctuated<MatchBranch, Token![,]>,
-}
-
-impl Parse for MatchBranch {
- fn parse(input: ParseStream) -> Result<Self> {
- let contents;
- let _: token::Bracket = bracketed!(contents in input);
-
- let pattern: Punctuated<MatchBranchPatternItem, Token![,]> =
- Punctuated::parse_terminated(&contents)?;
- use MatchBranchPatternItem::{Multiple, Single};
- let mut singles_before_multiple = Vec::new();
- let mut multiple = None;
- let mut singles_after_multiple = Vec::new();
- for item in pattern.clone() {
- 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,
- slice_token,
- } => {
- if multiple.is_none() {
- multiple = Some((rule_name, binder))
- } else {
- return Err(Error::new(
- slice_token.span(),
- "multiple variable-length patterns are not allowed",
- ));
- }
- }
- }
- }
-
- let _: Token![=>] = input.parse()?;
- let body = input.parse()?;
-
- Ok(MatchBranch {
- singles_before_multiple,
- multiple,
- singles_after_multiple,
- body,
- })
- }
-}
-
-impl Parse for MatchBranchPatternItem {
- fn parse(input: ParseStream) -> Result<Self> {
- let contents;
- let rule_name = input.parse()?;
- parenthesized!(contents in input);
- if input.peek(Token![..]) {
- let binder = contents.parse()?;
- let slice_token = input.parse()?;
- Ok(MatchBranchPatternItem::Multiple {
- rule_name,
- binder,
- slice_token,
- })
- } else if input.is_empty() || input.peek(Token![,]) {
- let binder = contents.parse()?;
- Ok(MatchBranchPatternItem::Single { rule_name, binder })
- } else {
- Err(input.error("expected `..` or nothing"))
- }
- }
-}
-
-impl Parse for MacroInput {
- fn parse(input: ParseStream) -> Result<Self> {
- let parser = if input.peek(token::Lt) {
- let _: token::Lt = input.parse()?;
- let parser = input.parse()?;
- let _: token::Gt = input.parse()?;
- let _: Token![;] = input.parse()?;
- parser
- } else {
- parse_quote!(Self)
- };
- let input_expr = input.parse()?;
- let _: Token![;] = input.parse()?;
- let branches = Punctuated::parse_terminated(input)?;
-
- Ok(MacroInput {
- parser,
- input_expr,
- branches,
- })
- }
-}
-
-fn make_branch(
- branch: &MatchBranch,
- i_nodes: &Ident,
- i_node_rules: &Ident,
- parser: &Type,
-) -> Result<TokenStream> {
- let aliased_rule = quote!(<#parser as ::pest_consume::Parser>::AliasedRule);
-
- // Find which branch to take
- let mut conditions = Vec::new();
- let start = branch.singles_before_multiple.len();
- let end = branch.singles_after_multiple.len();
- conditions.push(quote!(
- #start + #end <= #i_node_rules.len()
- ));
- for (i, (rule_name, _)) in branch.singles_before_multiple.iter().enumerate()
- {
- conditions.push(quote!(
- #i_node_rules[#i] == #aliased_rule::#rule_name
- ))
- }
- for (i, (rule_name, _)) in branch.singles_after_multiple.iter().enumerate()
- {
- conditions.push(quote!(
- #i_node_rules[#i_node_rules.len()-1 - #i] == #aliased_rule::#rule_name
- ))
- }
- if let Some((rule_name, _)) = &branch.multiple {
- conditions.push(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 == #aliased_rule::#rule_name
- )
- };
- all_match(&#i_node_rules[#start..#i_node_rules.len() - #end])
- }
- ))
- } else {
- // No variable-length pattern, so the size must be exactly the number of patterns
- conditions.push(quote!(
- #start + #end == #i_node_rules.len()
- ))
- }
-
- // Once we have found a branch that matches, we need to parse the nodes.
- let mut parses = Vec::new();
- for (rule_name, binder) in branch.singles_before_multiple.iter() {
- parses.push(quote!(
- let #binder = #parser::#rule_name(
- #i_nodes.next().unwrap()
- )?;
- ))
- }
- // Note the `rev()`: we are taking nodes from the end of the iterator in reverse order, so that
- // only the unmatched nodes are left in the iterator for the variable-length pattern, if any.
- for (rule_name, binder) in branch.singles_after_multiple.iter().rev() {
- parses.push(quote!(
- let #binder = #parser::#rule_name(
- #i_nodes.next_back().unwrap()
- )?;
- ))
- }
- if let Some((rule_name, binder)) = &branch.multiple {
- parses.push(quote!(
- let #binder = #i_nodes
- .map(|i| #parser::#rule_name(i))
- .collect::<::std::result::Result<::std::vec::Vec<_>, _>>()?
- .into_iter();
- ))
- }
-
- let body = &branch.body;
- Ok(quote!(
- _ if #(#conditions &&)* true => {
- #(#parses)*
- #body
- }
- ))
-}
-
-pub fn match_nodes(
- input: proc_macro::TokenStream,
-) -> Result<proc_macro2::TokenStream> {
- let input: MacroInput = syn::parse(input)?;
-
- let i_nodes = Ident::new("___nodes", input.input_expr.span());
- let i_node_rules = Ident::new("___node_rules", Span::call_site());
-
- let input_expr = &input.input_expr;
- let parser = &input.parser;
- let branches = input
- .branches
- .iter()
- .map(|br| make_branch(br, &i_nodes, &i_node_rules, parser))
- .collect::<Result<Vec<_>>>()?;
-
- Ok(quote!({
- #[allow(unused_mut)]
- let mut #i_nodes = #input_expr;
- let #i_node_rules = #i_nodes.aliased_rules::<#parser>();
-
- #[allow(unreachable_code)]
- match () {
- #(#branches,)*
- _ => return ::std::result::Result::Err(#i_nodes.error(
- std::format!("Nodes didn't match any pattern: {:?}", #i_node_rules)
- )),
- }
- }))
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-23 06:41:43 +0000