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#[macro_use]
extern crate combine;
use combine::char::{char, digit, space, string, Str};
use combine::error::FastResult::*;
use combine::error::{Consumed, StreamError, Tracked};
use combine::parser::combinator::{no_partial, recognize, NotFollowedBy, Try};
use combine::parser::error::Expected;
use combine::parser::function::EnvParser;
use combine::parser::item::Token;
use combine::parser::sequence::{Between, Skip};
use combine::stream::{RangeStream, Resetable, Stream, StreamOnce};
use combine::{
any, between, char, env_parser, from_str, many, not_followed_by, one_of, optional, parser,
satisfy, skip_many, skip_many1, token, try, unexpected, ConsumedResult, ParseError,
ParseResult, Parser,
};
use std::borrow::Cow;
use std::cell::RefCell;
use std::marker::PhantomData;
use combine::range::take;
pub type LanguageParser<'a, 'b, I, T> = Expected<EnvParser<&'b LanguageEnv<'a, I>, I, T>>;
pub type LexLanguageParser<'a, 'b, I, T> = Lex<'a, 'b, LanguageParser<'a, 'b, I, T>>;
pub struct Lex<'a: 'b, 'b, P>
where
P: Parser,
P::Input: Stream<Item = char> + 'b,
<P::Input as StreamOnce>::Error:
ParseError<char, <P::Input as StreamOnce>::Range, <P::Input as StreamOnce>::Position>,
{
parser: Skip<P, WhiteSpace<'a, 'b, P::Input>>,
}
impl<'a, 'b, P> Parser for Lex<'a, 'b, P>
where
P: Parser,
P::Input: Stream<Item = char> + 'b,
<P::Input as StreamOnce>::Error:
ParseError<char, <P::Input as StreamOnce>::Range, <P::Input as StreamOnce>::Position>,
{
type Input = P::Input;
type Output = P::Output;
type PartialState = ();
fn parse_stream(&mut self, input: &mut P::Input) -> ParseResult<P::Output, P::Input> {
self.parser.parse_stream(input)
}
fn parse_stream_consumed(
&mut self,
input: &mut P::Input,
) -> ConsumedResult<P::Output, P::Input> {
self.parser.parse_stream_consumed(input)
}
fn parse_lazy(&mut self, input: &mut P::Input) -> ConsumedResult<P::Output, P::Input> {
self.parser.parse_lazy(input).into()
}
fn add_error(&mut self, errors: &mut Tracked<<P::Input as StreamOnce>::Error>) {
self.parser.add_error(errors);
}
}
#[derive(Clone)]
pub struct WhiteSpace<'a: 'b, 'b, I>
where
I: Stream<Item = char> + 'b,
I::Error: ParseError<I::Item, I::Range, I::Position>,
{
env: &'b LanguageEnv<'a, I>,
}
impl<'a, 'b, I> Parser for WhiteSpace<'a, 'b, I>
where
I: Stream<Item = char> + 'b,
I::Error: ParseError<I::Item, I::Range, I::Position>,
{
type Input = I;
type Output = ();
type PartialState = ();
fn parse_lazy(&mut self, input: &mut I) -> ConsumedResult<(), I> {
let mut comment_start = self.env.comment_start.borrow_mut();
let mut comment_end = self.env.comment_end.borrow_mut();
let mut comment_line = self.env.comment_line.borrow_mut();
parse_comment(
&mut **comment_start,
&mut **comment_end,
&mut **comment_line,
input,
).into()
}
}
fn parse_comment<I, P>(
mut comment_start: P,
mut comment_end: P,
comment_line: P,
input: &mut I,
) -> ParseResult<(), I>
where
I: Stream<Item = char>,
P: Parser<Input = I, Output = ()>,
I::Error: ParseError<I::Item, I::Range, I::Position>,
{
let linecomment: &mut (Parser<Input = I, Output = (), PartialState = _>) =
&mut try(comment_line)
.and(skip_many(satisfy(|c| c != '\n')))
.map(|_| ());
let blockcomment = parser(|input| {
let (_, mut consumed) = try!(try(&mut comment_start).parse_lazy(input).into());
loop {
match consumed.combine(|_| try(&mut comment_end).parse_lazy(input).into()) {
Ok((_, consumed)) => return Ok(((), consumed)),
Err(_) => match consumed.combine(|_| any().parse_stream(input)) {
Ok((_, rest)) => consumed = rest,
Err(err) => return Err(err),
},
}
}
});
let whitespace = skip_many1(space()).or(linecomment).or(blockcomment);
skip_many(whitespace).parse_stream(input)
}
pub struct Reserved<'a: 'b, 'b, I>
where
I: Stream<Item = char> + 'b,
I::Error: ParseError<I::Item, I::Range, I::Position>,
{
parser: Lex<'a, 'b, Try<Skip<Str<I>, NotFollowedBy<LanguageParser<'a, 'b, I, char>>>>>,
}
impl<'a, 'b, I> Parser for Reserved<'a, 'b, I>
where
I: Stream<Item = char> + 'b,
I::Error: ParseError<I::Item, I::Range, I::Position>,
{
type Input = I;
type Output = &'static str;
type PartialState = ();
fn parse_stream(&mut self, input: &mut I) -> ParseResult<&'static str, I> {
self.parser.parse_stream(input)
}
fn parse_stream_consumed(&mut self, input: &mut I) -> ConsumedResult<&'static str, I> {
self.parser.parse_stream_consumed(input)
}
fn parse_lazy(&mut self, input: &mut I) -> ConsumedResult<&'static str, I> {
self.parser.parse_lazy(input).into()
}
fn add_error(&mut self, errors: &mut Tracked<I::Error>) {
self.parser.add_error(errors);
}
}
pub struct BetweenChar<'a: 'b, 'b, P>
where
P: Parser,
P::Input: Stream<Item = char> + 'b,
<P::Input as StreamOnce>::Error:
ParseError<char, <P::Input as StreamOnce>::Range, <P::Input as StreamOnce>::Position>,
{
parser: Between<Lex<'a, 'b, Token<P::Input>>, Lex<'a, 'b, Token<P::Input>>, P>,
}
impl<'a, 'b, I, P> Parser for BetweenChar<'a, 'b, P>
where
I: Stream<Item = char> + 'b,
P: Parser<Input = I>,
I::Error: ParseError<I::Item, I::Range, I::Position>,
{
type Input = I;
type Output = P::Output;
type PartialState = ();
fn parse_stream(&mut self, input: &mut I) -> ParseResult<P::Output, I> {
self.parser.parse_stream(input)
}
fn parse_stream_consumed(&mut self, input: &mut I) -> ConsumedResult<P::Output, I> {
self.parser.parse_stream_consumed(input)
}
fn parse_lazy(&mut self, input: &mut I) -> ConsumedResult<P::Output, I> {
self.parser.parse_lazy(input).into()
}
fn add_error(&mut self, errors: &mut Tracked<<P::Input as StreamOnce>::Error>) {
self.parser.add_error(errors);
}
}
pub struct Identifier<PS, P>
where
PS: Parser<Output = char>,
P: Parser<Input = PS::Input, Output = char>,
{
pub start: PS,
pub rest: P,
pub reserved: Vec<Cow<'static, str>>,
}
pub struct LanguageDef<IS, I, OS, O, CL, CS, CE>
where
I: Parser<Output = char>,
IS: Parser<Input = I::Input, Output = char>,
O: Parser<Input = I::Input, Output = char>,
OS: Parser<Input = I::Input, Output = char>,
CL: Parser<Input = I::Input, Output = ()>,
CS: Parser<Input = I::Input, Output = ()>,
CE: Parser<Input = I::Input, Output = ()>,
{
pub ident: Identifier<IS, I>,
pub op: Identifier<OS, O>,
pub comment_line: CL,
pub comment_start: CS,
pub comment_end: CE,
}
type IdentParser<'a, I> = (
Box<Parser<Input = I, Output = char, PartialState = ()> + 'a>,
Box<Parser<Input = I, Output = char, PartialState = ()> + 'a>,
);
pub struct LanguageEnv<'a, I> {
ident: RefCell<IdentParser<'a, I>>,
reserved: Vec<Cow<'static, str>>,
op: RefCell<IdentParser<'a, I>>,
op_reserved: Vec<Cow<'static, str>>,
comment_line: RefCell<Box<Parser<Input = I, Output = (), PartialState = ()> + 'a>>,
comment_start: RefCell<Box<Parser<Input = I, Output = (), PartialState = ()> + 'a>>,
comment_end: RefCell<Box<Parser<Input = I, Output = (), PartialState = ()> + 'a>>,
buffer: RefCell<String>,
_marker: PhantomData<fn(I) -> I>,
}
impl<'a, I> LanguageEnv<'a, I>
where
I: Stream<Item = char>,
I::Error: ParseError<I::Item, I::Range, I::Position>,
{
pub fn new<A, B, C, D, E, F, G>(def: LanguageDef<A, B, C, D, E, F, G>) -> LanguageEnv<'a, I>
where
A: Parser<Input = I, Output = char> + 'a,
B: Parser<Input = I, Output = char> + 'a,
C: Parser<Input = I, Output = char> + 'a,
D: Parser<Input = I, Output = char> + 'a,
E: Parser<Input = I, Output = ()> + 'a,
F: Parser<Input = I, Output = ()> + 'a,
G: Parser<Input = I, Output = ()> + 'a,
{
let LanguageDef {
ident:
Identifier {
start: ident_start,
rest: ident_rest,
reserved: ident_reserved,
},
op:
Identifier {
start: op_start,
rest: op_rest,
reserved: op_reserved,
},
comment_line,
comment_start,
comment_end,
} = def;
LanguageEnv {
ident: RefCell::new((
Box::new(no_partial(ident_start)),
Box::new(no_partial(ident_rest)),
)),
reserved: ident_reserved,
op: RefCell::new((
Box::new(no_partial(op_start)),
Box::new(no_partial(op_rest)),
)),
op_reserved: op_reserved,
comment_line: RefCell::new(Box::new(no_partial(comment_line))),
comment_start: RefCell::new(Box::new(no_partial(comment_start))),
comment_end: RefCell::new(Box::new(no_partial(comment_end))),
buffer: RefCell::new(String::new()),
_marker: PhantomData,
}
}
fn parser<'b, T>(
&'b self,
parser: fn(&LanguageEnv<'a, I>, &mut I) -> ParseResult<T, I>,
expected: &'static str,
) -> LanguageParser<'a, 'b, I, T> {
env_parser(self, parser).expected(expected)
}
pub fn lex<'b, P>(&'b self, p: P) -> Lex<'a, 'b, P>
where
P: Parser<Input = I> + 'b,
{
Lex {
parser: p.skip(self.white_space()),
}
}
pub fn white_space<'b>(&'b self) -> WhiteSpace<'a, 'b, I> {
WhiteSpace { env: self }
}
pub fn symbol<'b>(&'b self, name: &'static str) -> Lex<'a, 'b, Str<I>> {
self.lex(string(name))
}
pub fn identifier<'b>(&'b self) -> LexLanguageParser<'a, 'b, I, String> {
self.lex(self.identifier_())
}
pub fn identifier_<'b>(&'b self) -> LanguageParser<'a, 'b, I, String> {
self.parser(LanguageEnv::<I>::parse_ident, "identifier")
}
fn parse_ident(&self, input: &mut I) -> ParseResult<String, I> {
let mut ident = self.ident.borrow_mut();
let (first, _) = try!(ident.0.parse_lazy(input).into());
let mut buffer = String::new();
buffer.push(first);
let (s, consumed) = {
let mut iter = (&mut *ident.1).iter(input);
buffer.extend(iter.by_ref());
try!(Consumed::Consumed(()).combine(|_| iter.into_result(buffer)))
};
match self.reserved.iter().find(|r| **r == s) {
Some(ref _reserved) => Err(consumed.map(|_| {
I::Error::from_error(
input.position(),
StreamError::expected_static_message("identifier"),
).into()
})),
None => Ok((s, consumed)),
}
}
pub fn range_identifier<'b>(&'b self) -> LexLanguageParser<'a, 'b, I, &'a str>
where
I: RangeStream<Range = &'a str>,
{
self.lex(self.range_identifier_())
}
pub fn range_identifier_<'b>(&'b self) -> LanguageParser<'a, 'b, I, &'a str>
where
I: RangeStream<Range = &'a str>,
{
self.parser(LanguageEnv::<I>::parse_range_ident, "identifier")
}
fn parse_range_ident(&self, input: &mut I) -> ParseResult<&'a str, I>
where
I: RangeStream<Range = &'a str>,
{
let mut ident = self.ident.borrow_mut();
let checkpoint = input.checkpoint();
let (first, _) = try!(ident.0.parse_lazy(input).into());
let len = {
let mut iter = (&mut *ident.1).iter(input);
iter.by_ref()
.fold(first.len_utf8(), |acc, c| c.len_utf8() + acc)
};
input.reset(checkpoint);
let (s, consumed) = try!(take(len).parse_lazy(input).into());
match self.reserved.iter().find(|r| **r == s) {
Some(ref _reserved) => Err(consumed.map(|_| {
I::Error::from_error(
input.position(),
StreamError::expected_static_message("identifier"),
).into()
})),
None => Ok((s, consumed)),
}
}
pub fn reserved<'b>(&'b self, name: &'static str) -> Reserved<'a, 'b, I>
where
I::Range: 'b,
{
let ident_letter = self.parser(LanguageEnv::<I>::ident_letter, "identifier letter");
Reserved {
parser: self.lex(try(string(name).skip(not_followed_by(ident_letter)))),
}
}
fn ident_letter(&self, input: &mut I) -> ParseResult<char, I> {
self.ident.borrow_mut().1.parse_lazy(input).into()
}
pub fn op<'b>(&'b self) -> LexLanguageParser<'a, 'b, I, String> {
self.lex(self.op_())
}
pub fn op_<'b>(&'b self) -> LanguageParser<'a, 'b, I, String> {
self.parser(LanguageEnv::<I>::parse_op, "operator")
}
fn parse_op(&self, input: &mut I) -> ParseResult<String, I> {
let mut op = self.op.borrow_mut();
let (first, _) = try!(op.0.parse_lazy(input).into());
let mut buffer = String::new();
buffer.push(first);
let (s, consumed) = {
let mut iter = (&mut *op.1).iter(input);
buffer.extend(iter.by_ref());
try!(Consumed::Consumed(()).combine(|_| iter.into_result(buffer)))
};
match self.op_reserved.iter().find(|r| **r == s) {
Some(ref _reserved) => Err(consumed.map(|_| {
I::Error::from_error(
input.position(),
StreamError::expected_static_message("operator"),
).into()
})),
None => Ok((s, consumed)),
}
}
pub fn range_op<'b>(&'b self) -> LexLanguageParser<'a, 'b, I, &'a str>
where
I: RangeStream<Range = &'a str>,
{
self.lex(self.range_op_())
}
pub fn range_op_<'b>(&'b self) -> LanguageParser<'a, 'b, I, &'a str>
where
I: RangeStream<Range = &'a str>,
{
self.parser(LanguageEnv::<I>::parse_range_op, "operator")
}
fn parse_range_op(&self, input: &mut I) -> ParseResult<&'a str, I>
where
I: RangeStream<Range = &'a str>,
{
let mut op = self.op.borrow_mut();
let checkpoint = input.checkpoint();
let (first, _) = try!(op.0.parse_lazy(input).into());
let len = {
let mut iter = (&mut *op.1).iter(input);
iter.by_ref()
.fold(first.len_utf8(), |acc, c| c.len_utf8() + acc)
};
input.reset(checkpoint);
let (s, consumed) = try!(take(len).parse_lazy(input).into());
match self.op_reserved.iter().find(|r| **r == s) {
Some(ref _reserved) => Err(consumed.map(|_| {
I::Error::from_error(
input.position(),
StreamError::expected_static_message("identifier"),
).into()
})),
None => Ok((s, consumed)),
}
}
pub fn reserved_op<'b>(&'b self, name: &'static str) -> Lex<'a, 'b, Reserved<'a, 'b, I>>
where
I::Range: 'b,
{
self.lex(self.reserved_op_(name))
}
pub fn reserved_op_<'b>(&'b self, name: &'static str) -> Reserved<'a, 'b, I>
where
I::Range: 'b,
{
let op_letter = self.parser(LanguageEnv::<I>::op_letter, "operator letter");
Reserved {
parser: self.lex(try(string(name).skip(not_followed_by(op_letter)))),
}
}
fn op_letter(&self, input: &mut I) -> ParseResult<char, I> {
self.op.borrow_mut().1.parse_lazy(input).into()
}
pub fn char_literal<'b>(&'b self) -> LexLanguageParser<'a, 'b, I, char> {
self.lex(self.char_literal_())
}
pub fn char_literal_<'b>(&'b self) -> LanguageParser<'a, 'b, I, char> {
self.parser(LanguageEnv::<I>::char_literal_parser, "character")
}
fn char_literal_parser(&self, input: &mut I) -> ParseResult<char, I> {
between(string("\'"), string("\'"), parser(LanguageEnv::<I>::char))
.expected("character")
.parse_lazy(input)
.into()
}
fn char(input: &mut I) -> ParseResult<char, I> {
let (c, consumed) = try!(any().parse_lazy(input).into());
let mut back_slash_char =
satisfy(|c| "'\\/bfnrt".chars().find(|x| *x == c).is_some()).map(escape_char);
match c {
'\\' => consumed.combine(|_| back_slash_char.parse_stream(input)),
'\'' => unexpected("'").parse_stream(input).map(|_| unreachable!()),
_ => Ok((c, consumed)),
}
}
pub fn string_literal<'b>(&'b self) -> LexLanguageParser<'a, 'b, I, String> {
self.lex(self.string_literal_())
}
pub fn string_literal_<'b>(&'b self) -> LanguageParser<'a, 'b, I, String> {
self.parser(LanguageEnv::<I>::string_literal_parser, "string")
}
fn string_literal_parser(&self, input: &mut I) -> ParseResult<String, I> {
between(
string("\""),
string("\""),
many(parser(LanguageEnv::<I>::string_char)),
).parse_lazy(input)
.into()
}
fn string_char(input: &mut I) -> ParseResult<char, I> {
let (c, consumed) = try!(any().parse_lazy(input).into());
let mut back_slash_char =
satisfy(|c| "\"\\/bfnrt".chars().find(|x| *x == c).is_some()).map(escape_char);
match c {
'\\' => consumed.combine(|_| back_slash_char.parse_stream(input)),
'"' => unexpected("\"").parse_stream(input).map(|_| unreachable!()),
_ => Ok((c, consumed)),
}
}
pub fn angles<'b, P>(&'b self, parser: P) -> BetweenChar<'a, 'b, P>
where
P: Parser<Input = I>,
I::Range: 'b,
{
self.between('<', '>', parser)
}
pub fn braces<'b, P>(&'b self, parser: P) -> BetweenChar<'a, 'b, P>
where
P: Parser<Input = I>,
I::Range: 'b,
{
self.between('{', '}', parser)
}
pub fn brackets<'b, P>(&'b self, parser: P) -> BetweenChar<'a, 'b, P>
where
P: Parser<Input = I>,
I::Range: 'b,
{
self.between('[', ']', parser)
}
pub fn parens<'b, P>(&'b self, parser: P) -> BetweenChar<'a, 'b, P>
where
P: Parser<Input = I>,
I::Range: 'b,
{
self.between('(', ')', parser)
}
fn between<'b, P>(&'b self, start: char, end: char, parser: P) -> BetweenChar<'a, 'b, P>
where
P: Parser<Input = I>,
I::Range: 'b,
{
BetweenChar {
parser: between(self.lex(char(start)), self.lex(char(end)), parser),
}
}
pub fn integer<'b>(&'b self) -> LexLanguageParser<'a, 'b, I, i64> {
self.lex(self.integer_())
}
pub fn integer_<'b>(&'b self) -> LanguageParser<'a, 'b, I, i64> {
self.parser(LanguageEnv::integer_parser, "integer")
}
fn integer_parser(&self, input: &mut I) -> ParseResult<i64, I> {
let mut buffer = self.buffer.borrow_mut();
buffer.clear();
let ((), consumed) = try!(LanguageEnv::push_digits(&mut buffer, input));
match buffer.parse() {
Ok(i) => Ok((i, consumed)),
Err(_) => Err(consumed.map(|()| I::Error::empty(input.position()).into())),
}
}
fn push_digits(buffer: &mut String, input: &mut I) -> ParseResult<(), I> {
let mut iter = digit().iter(input);
buffer.extend(&mut iter);
iter.into_result(())
}
pub fn float<'b>(&'b self) -> LexLanguageParser<'a, 'b, I, f64> {
self.lex(self.float_())
}
pub fn float_<'b>(&'b self) -> LanguageParser<'a, 'b, I, f64> {
self.parser(|_, input| float().parse_stream(input), "float")
}
}
pub fn float<I>() -> impl Parser<Input = I, Output = f64>
where
I: Stream<Item = char>,
I::Error: ParseError<I::Item, I::Range, I::Position>,
{
from_str(recognize::<String, _>((
optional(token('-')),
token('0').or((
skip_many1(digit()),
optional((token('.'), skip_many(digit()))),
)
.map(|_| '0')),
optional((
(one_of("eE".chars()), optional(one_of("+-".chars()))),
skip_many1(digit()),
)),
))).expected("float")
}
fn escape_char(c: char) -> char {
match c {
'\'' => '\'',
'"' => '"',
'\\' => '\\',
'/' => '/',
'b' => '\u{0008}',
'f' => '\u{000c}',
'n' => '\n',
'r' => '\r',
't' => '\t',
c => c,
}
}
#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Debug)]
pub enum Fixity {
Left,
Right,
}
#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Debug)]
pub struct Assoc {
pub fixity: Fixity,
pub precedence: i32,
}
#[derive(Clone, Debug)]
pub struct Expression<O, P, F> {
term: P,
op: O,
f: F,
}
macro_rules! tryb {
($e: expr) => {
match $e {
EmptyOk(x) => (x, Consumed::Empty(())),
ConsumedOk(x) => (x, Consumed::Consumed(())),
EmptyErr(_) => break,
ConsumedErr(err) => return Err(Consumed::Consumed(err.into())),
}
};
}
impl<O, P, F, T> Expression<O, P, F>
where
O: Parser<Output = (T, Assoc)>,
P: Parser<Input = O::Input>,
F: Fn(P::Output, T, P::Output) -> P::Output,
{
fn parse_expr(
&mut self,
min_precedence: i32,
mut l: P::Output,
mut consumed: Consumed<()>,
input: &mut P::Input,
) -> ParseResult<P::Output, P::Input> {
loop {
let checkpoint = input.checkpoint();
let ((op, op_assoc), rest) = tryb!(self.op.parse_lazy(input));
if op_assoc.precedence < min_precedence {
input.reset(checkpoint);
return Ok((l, consumed));
}
let (mut r, rest) = try!(rest.combine(|_| self.term.parse_stream(input)));
consumed = rest;
loop {
let checkpoint = input.checkpoint();
let ((_, assoc), _) = tryb!(self.op.parse_lazy(input));
input.reset(checkpoint);
let proceed = assoc.precedence > op_assoc.precedence
|| assoc.fixity == Fixity::Right && assoc.precedence == op_assoc.precedence;
if !proceed {
break;
}
let (new_r, rest) = try!(self.parse_expr(assoc.precedence, r, consumed, input));
r = new_r;
consumed = rest;
}
l = (self.f)(l, op, r);
}
Ok((l, consumed))
}
}
impl<O, P, F, T> Parser for Expression<O, P, F>
where
O: Parser<Output = (T, Assoc)>,
P: Parser<Input = O::Input>,
F: Fn(P::Output, T, P::Output) -> P::Output,
{
type Input = P::Input;
type Output = P::Output;
type PartialState = ();
fn parse_lazy(&mut self, input: &mut Self::Input) -> ConsumedResult<Self::Output, Self::Input> {
let (l, consumed) = ctry!(self.term.parse_lazy(input));
self.parse_expr(0, l, consumed, input).into()
}
fn add_error(&mut self, errors: &mut Tracked<<P::Input as StreamOnce>::Error>) {
self.term.add_error(errors);
}
}
pub fn expression_parser<O, P, F, T>(term: P, op: O, f: F) -> Expression<O, P, F>
where
O: Parser<Output = (T, Assoc)>,
P: Parser<Input = O::Input>,
F: Fn(P::Output, T, P::Output) -> P::Output,
{
Expression {
term: term,
op: op,
f: f,
}
}
#[cfg(test)]
mod tests {
use super::*;
use combine::char::{alpha_num, letter, string};
use combine::easy::Error;
use combine::parser::combinator::opaque;
use combine::*;
fn env<I>() -> LanguageEnv<'static, I>
where
I: Stream<Item = char> + 'static,
I::Error: ParseError<I::Item, I::Range, I::Position>,
{
LanguageEnv::new(LanguageDef {
ident: Identifier {
start: letter(),
rest: alpha_num(),
reserved: ["if", "then", "else", "let", "in", "type"]
.iter()
.map(|x| (*x).into())
.collect(),
},
op: Identifier {
start: satisfy(|c| "+-*/".chars().find(|x| *x == c).is_some()),
rest: satisfy(|c| "+-*/".chars().find(|x| *x == c).is_some()),
reserved: ["+", "-", "*", "/"].iter().map(|x| (*x).into()).collect(),
},
comment_start: string("/*").map(|_| ()),
comment_end: string("*/").map(|_| ()),
comment_line: string("//").map(|_| ()),
})
}
#[test]
fn string_literal() {
let result = env().string_literal().easy_parse(r#""abc\n\r213" "#);
assert_eq!(result, Ok(("abc\n\r213".to_string(), "")));
}
#[test]
fn char_literal() {
let e = env();
let mut parser = e.char_literal();
assert_eq!(parser.easy_parse("'a'"), Ok(('a', "")));
assert_eq!(parser.easy_parse(r#"'\n'"#), Ok(('\n', "")));
assert_eq!(parser.easy_parse(r#"'\\'"#), Ok(('\\', "")));
assert!(parser.easy_parse(r#"'\1'"#).is_err());
assert_eq!(parser.easy_parse(r#"'"'"#), Ok(('"', "")));
assert!(parser.easy_parse(r#"'\"'"#).is_err());
}
#[test]
fn integer_literal() {
let result = env().integer().easy_parse("213 ");
assert_eq!(result, Ok((213, "")));
}
#[test]
fn float_literal() {
let result = env().float().easy_parse("123.456 ");
assert_eq!(result, Ok((123.456, "")));
let result = env().float().easy_parse("123.456e10 ");
assert_eq!(result, Ok((123.456e10, "")));
let result = env().float().easy_parse("123.456E-10 ");
assert_eq!(result, Ok((123.456E-10, "")));
let result = env().float().easy_parse("123e1 ");
assert_eq!(result, Ok((123e1, "")));
}
#[test]
fn identifier() {
let e = env();
let result = e.identifier().easy_parse("a12bc");
assert_eq!(result, Ok(("a12bc".to_string(), "")));
assert!(e.identifier().easy_parse("1bcv").is_err());
assert!(e.identifier().easy_parse("if").is_err());
assert_eq!(e.reserved("if").easy_parse("if"), Ok(("if", "")));
assert!(e.reserved("if").easy_parse("ifx").is_err());
}
#[test]
fn operator() {
let e = env();
let result = e.op().easy_parse("++ ");
assert_eq!(result, Ok(("++".to_string(), "")));
assert!(e.identifier().easy_parse("+").is_err());
assert_eq!(e.reserved_op("-").easy_parse("- "), Ok(("-", "")));
assert!(e.reserved_op("-").easy_parse("-- ").is_err());
}
use self::Expr::*;
#[derive(PartialEq, Debug)]
enum Expr {
Int(i64),
Op(Box<Expr>, &'static str, Box<Expr>),
}
fn op(l: Expr, op: &'static str, r: Expr) -> Expr {
Expr::Op(Box::new(l), op, Box::new(r))
}
fn test_expr1() -> (&'static str, Expr) {
let mul_2_3 = op(Int(2), "*", Int(3));
let div_4_5 = op(Int(4), "/", Int(5));
(
"1 + 2 * 3 - 4 / 5",
op(op(Int(1), "+", mul_2_3), "-", div_4_5),
)
}
fn test_expr2() -> (&'static str, Expr) {
let mul_2_3_4 = op(op(Int(2), "*", Int(3)), "/", Int(4));
let add_1_mul = op(Int(1), "+", mul_2_3_4);
(
"1 + 2 * 3 / 4 - 5 + 6",
op(op(add_1_mul, "-", Int(5)), "+", Int(6)),
)
}
parser!{
fn op_parser[I]()(I) -> (&'static str, Assoc)
where [I: Stream<Item = char>,]
{
opaque(|f| {
let mut ops = ["*", "/", "+", "-", "^", "&&", "||", "!!"]
.iter()
.cloned()
.map(string)
.collect::<Vec<_>>();
f(&mut choice(&mut ops[..])
.map(|s| {
let prec = match s {
"||" => 2,
"&&" => 3,
"+" | "-" => 6,
"*" | "/" => 7,
"^" => 8,
"!!" => 9,
_ => panic!("Impossible"),
};
let fixity = match s {
"+" | "-" | "*" | "/" => Fixity::Left,
"^" | "&&" | "||" => Fixity::Right,
_ => panic!("Impossible"),
};
(
s,
Assoc {
fixity: fixity,
precedence: prec,
},
)
}))
})
}
}
#[test]
fn expression() {
let e = env();
let mut expr = expression_parser(e.integer().map(Expr::Int), e.lex(op_parser()), op);
let (s1, e1) = test_expr1();
let result = expr.easy_parse(s1);
assert_eq!(result, Ok((e1, "")));
let (s2, e2) = test_expr2();
let result = expr.easy_parse(s2);
assert_eq!(result, Ok((e2, "")));
}
#[test]
fn right_assoc_expression() {
let e = env();
let mut expr = expression_parser(e.integer().map(Expr::Int), e.lex(op_parser()), op);
let result = expr.easy_parse("1 + 2 * 3 ^ 4 / 5");
let power_3_4 = op(Int(3), "^", Int(4));
let mul_2_3_5 = op(op(Int(2), "*", power_3_4), "/", Int(5));
let add_1_mul = op(Int(1), "+", mul_2_3_5);
assert_eq!(result, Ok((add_1_mul, "")));
let result = expr.easy_parse("1 ^ 2 && 3 ^ 4");
let e_1_2 = op(Int(1), "^", Int(2));
let e_3_4 = op(Int(3), "^", Int(4));
assert_eq!(result, Ok((op(e_1_2, "&&", e_3_4), "")));
}
#[test]
fn expression_error() {
let e = env();
let mut expr = expression_parser(e.integer().map(Expr::Int), e.lex(op_parser()), op);
let errors = expr.easy_parse("+ 1").map_err(|err| err.errors);
assert_eq!(
errors,
Err(vec![
Error::Unexpected('+'.into()),
Error::Expected("integer".into()),
])
);
}
#[test]
fn range_identifier() {
let e = env();
let mut id = e.range_identifier();
assert_eq!(id.easy_parse("t"), Ok(("t", "")));
assert_eq!(id.easy_parse("test123 123"), Ok(("test123", "123")));
assert_eq!(
id.easy_parse("123").map_err(|err| err.errors),
Err(vec![
Error::Unexpected('1'.into()),
Error::Expected("identifier".into()),
])
);
}
#[test]
fn range_operator() {
let e = env();
let mut id = e.range_op();
assert_eq!(id.easy_parse("+-+ 123"), Ok(("+-+", "123")));
assert_eq!(
id.easy_parse("abc").map_err(|err| err.errors),
Err(vec![
Error::Unexpected('a'.into()),
Error::Expected("operator".into()),
])
);
}
}