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Pre: Move macros out of lib.rs.

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It seems very subtle to use macros in tests: I needed to separate the
modules in order to control load order to get everything to work.
This commit is contained in:
Nick Alexander 2017-04-28 14:09:57 -07:00
parent 953f9f7734
commit 4fa57942d3
2 changed files with 127 additions and 102 deletions
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104
parser-utils/src/lib.rs
View file

@ -11,13 +11,8 @@
extern crate combine;
extern crate edn;
use combine::{
ParseResult,
};
use combine::combinator::{
Expected,
FnParser,
};
#[macro_use]
pub mod macros;
pub mod log;
pub mod value_and_span;
@ -26,13 +21,6 @@ pub use log::{
LogParsing,
};
/// A type definition for a function parser that either parses an `O` from an input stream of type
/// `I`, or fails with an "expected" failure.
/// See <https://docs.rs/combine/2.2.1/combine/trait.Parser.html#method.expected> for more
/// illumination.
/// Nothing about this is specific to the result type of the parser.
pub type ResultParser<O, I> = Expected<FnParser<I, fn(I) -> ParseResult<O, I>>>;
/// `assert_parses_to!` simplifies some of the boilerplate around running a
/// parser function against input and expecting a certain result.
#[macro_export]
@ -56,94 +44,6 @@ macro_rules! assert_edn_parses_to {
}}
}
/// `satisfy_unwrap!` makes it a little easier to implement a `satisfy_map`
/// body that matches a particular `Value` enum case, otherwise returning `None`.
#[macro_export]
macro_rules! satisfy_unwrap {
( $cas: path, $var: ident, $body: block ) => {
satisfy_map(|x: edn::Value| if let $cas($var) = x $body else { None })
}
}
/// Generate a `satisfy_map` expression that matches a `PlainSymbol`
/// value with the given name.
///
/// We do this rather than using `combine::token` so that we don't
/// need to allocate a new `String` inside a `PlainSymbol` inside a `Value`
/// just to match input.
#[macro_export]
macro_rules! matches_plain_symbol {
($name: expr, $input: ident) => {
satisfy_map(|x: edn::Value| {
if let edn::Value::PlainSymbol(ref s) = x {
if s.0.as_str() == $name {
return Some(());
}
}
return None;
}).parse_stream($input)
}
}
/// Define an `impl` body for the `$parser` type. The body will contain a parser
/// function called `$name`, consuming a stream of `$item_type`s. The parser's
/// result type will be `$result_type`.
///
/// The provided `$body` will be evaluated with `$input` bound to the input stream.
///
/// `$body`, when run, should return a `ParseResult` of the appropriate result type.
#[macro_export]
macro_rules! def_parser_fn {
( $parser: ident, $name: ident, $item_type: ty, $result_type: ty, $input: ident, $body: block ) => {
impl<I> $parser<I> where I: Stream<Item = $item_type> {
fn $name() -> ResultParser<$result_type, I> {
fn inner<I: Stream<Item = $item_type>>($input: I) -> ParseResult<$result_type, I> {
$body
}
parser(inner as fn(I) -> ParseResult<$result_type, I>).expected(stringify!($name))
}
}
}
}
#[macro_export]
macro_rules! def_parser {
( $parser: ident, $name: ident, $result_type: ty, $body: block ) => {
impl $parser {
fn $name() -> ResultParser<$result_type, $crate::value_and_span::Stream> {
fn inner(input: $crate::value_and_span::Stream) -> ParseResult<$result_type, $crate::value_and_span::Stream> {
$body.parse_lazy(input).into()
}
parser(inner as fn($crate::value_and_span::Stream) -> ParseResult<$result_type, $crate::value_and_span::Stream>).expected(stringify!($name))
}
}
}
}
/// `def_value_parser_fn` is a short-cut to `def_parser_fn` with the input type
/// being `edn::Value`.
#[macro_export]
macro_rules! def_value_parser_fn {
( $parser: ident, $name: ident, $result_type: ty, $input: ident, $body: block ) => {
def_parser_fn!($parser, $name, edn::Value, $result_type, $input, $body);
}
}
/// `def_value_satisfy_parser_fn` is a short-cut to `def_parser_fn` with the input type
/// being `edn::Value` and the body being a call to `satisfy_map` with the given transformer.
///
/// In practice this allows you to simply pass a function that accepts an `&edn::Value` and
/// returns an `Option<$result_type>`: if a suitable value is at the front of the stream,
/// it will be converted and returned by the parser; otherwise, the parse will fail.
#[macro_export]
macro_rules! def_value_satisfy_parser_fn {
( $parser: ident, $name: ident, $result_type: ty, $transformer: path ) => {
def_value_parser_fn!($parser, $name, $result_type, input, {
satisfy_map(|x: edn::Value| $transformer(&x)).parse_stream(input)
});
}
}
/// A `ValueParseError` is a `combine::primitives::ParseError`-alike that implements the `Debug`,
/// `Display`, and `std::error::Error` traits. In addition, it doesn't capture references, making
/// it possible to store `ValueParseError` instances in local links with the `error-chain` crate.

125
parser-utils/src/macros.rs Normal file
View file

@ -0,0 +1,125 @@
// Copyright 2016 Mozilla
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
// this file except in compliance with the License. You may obtain a copy of the
// License at http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.
// use combine::{
// ParseResult,
// };
// use combine::combinator::{
// Expected,
// FnParser,
// };
use combine::{
ParseResult,
};
// use combine::primitives; // To not shadow Error.
// use combine::primitives::{
// Consumed,
// FastResult,
// };
use combine::combinator::{
Expected,
FnParser,
};
/// A type definition for a function parser that either parses an `O` from an input stream of type
/// `I`, or fails with an "expected" failure.
/// See <https://docs.rs/combine/2.2.1/combine/trait.Parser.html#method.expected> for more
/// illumination.
/// Nothing about this is specific to the result type of the parser.
pub type ResultParser<O, I> = Expected<FnParser<I, fn(I) -> ParseResult<O, I>>>;
/// `satisfy_unwrap!` makes it a little easier to implement a `satisfy_map`
/// body that matches a particular `Value` enum case, otherwise returning `None`.
#[macro_export]
macro_rules! satisfy_unwrap {
( $cas: path, $var: ident, $body: block ) => {
satisfy_map(|x: edn::Value| if let $cas($var) = x $body else { None })
}
}
/// Generate a `satisfy_map` expression that matches a `PlainSymbol`
/// value with the given name.
///
/// We do this rather than using `combine::token` so that we don't
/// need to allocate a new `String` inside a `PlainSymbol` inside a `Value`
/// just to match input.
#[macro_export]
macro_rules! matches_plain_symbol {
($name: expr, $input: ident) => {
satisfy_map(|x: edn::Value| {
if let edn::Value::PlainSymbol(ref s) = x {
if s.0.as_str() == $name {
return Some(());
}
}
return None;
}).parse_stream($input)
}
}
/// Define an `impl` body for the `$parser` type. The body will contain a parser
/// function called `$name`, consuming a stream of `$item_type`s. The parser's
/// result type will be `$result_type`.
///
/// The provided `$body` will be evaluated with `$input` bound to the input stream.
///
/// `$body`, when run, should return a `ParseResult` of the appropriate result type.
#[macro_export]
macro_rules! def_parser_fn {
( $parser: ident, $name: ident, $item_type: ty, $result_type: ty, $input: ident, $body: block ) => {
impl<I> $parser<I> where I: Stream<Item = $item_type> {
fn $name() -> ResultParser<$result_type, I> {
fn inner<I: Stream<Item = $item_type>>($input: I) -> ParseResult<$result_type, I> {
$body
}
parser(inner as fn(I) -> ParseResult<$result_type, I>).expected(stringify!($name))
}
}
}
}
#[macro_export]
macro_rules! def_parser {
( $parser: ident, $name: ident, $result_type: ty, $body: block ) => {
impl $parser {
fn $name() -> ResultParser<$result_type, $crate::value_and_span::Stream> {
fn inner(input: $crate::value_and_span::Stream) -> ParseResult<$result_type, $crate::value_and_span::Stream> {
$body.parse_lazy(input).into()
}
parser(inner as fn($crate::value_and_span::Stream) -> ParseResult<$result_type, $crate::value_and_span::Stream>).expected(stringify!($name))
}
}
}
}
/// `def_value_parser_fn` is a short-cut to `def_parser_fn` with the input type
/// being `edn::Value`.
#[macro_export]
macro_rules! def_value_parser_fn {
( $parser: ident, $name: ident, $result_type: ty, $input: ident, $body: block ) => {
def_parser_fn!($parser, $name, edn::Value, $result_type, $input, $body);
}
}
/// `def_value_satisfy_parser_fn` is a short-cut to `def_parser_fn` with the input type
/// being `edn::Value` and the body being a call to `satisfy_map` with the given transformer.
///
/// In practice this allows you to simply pass a function that accepts an `&edn::Value` and
/// returns an `Option<$result_type>`: if a suitable value is at the front of the stream,
/// it will be converted and returned by the parser; otherwise, the parse will fail.
#[macro_export]
macro_rules! def_value_satisfy_parser_fn {
( $parser: ident, $name: ident, $result_type: ty, $transformer: path ) => {
def_value_parser_fn!($parser, $name, $result_type, input, {
satisfy_map(|x: edn::Value| $transformer(&x)).parse_stream(input)
});
}
}