language-servers/roc
1
0
Fork 0
mirror of https://github.com/roc-lang/roc.git synced 2025-11-04 06:38:28 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 6
roc/crates/compiler/parse/src/parser.rs
Joshua Warner 5cd38c969f
Fix a couple minor parsing bugs
2024-12-01 12:40:17 -08:00

2675 lines
83 KiB
Rust
Raw Blame History

use crate::state::State;
use bumpalo::collections::vec::Vec;
use bumpalo::Bump;
use roc_region::all::{Loc, Position, Region};
use Progress::*;
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum Either<First, Second> {
First(First),
Second(Second),
}
impl<F: Copy, S: Copy> Copy for Either<F, S> {}
pub type ParseResult<'a, Output, Error> = Result<(Progress, Output, State<'a>), (Progress, Error)>;
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Progress {
MadeProgress,
NoProgress,
}
impl Progress {
pub fn from_lengths(before: usize, after: usize) -> Self {
Self::from_consumed(before - after)
}
pub fn from_consumed(chars_consumed: usize) -> Self {
Self::progress_when(chars_consumed != 0)
}
pub fn progress_when(made_progress: bool) -> Self {
if made_progress {
Progress::MadeProgress
} else {
Progress::NoProgress
}
}
pub fn or(&self, other: Self) -> Self {
if (*self == MadeProgress) || (other == MadeProgress) {
MadeProgress
} else {
NoProgress
}
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum SyntaxError<'a> {
Unexpected(Region),
OutdentedTooFar,
Eof(Region),
InvalidPattern,
BadUtf8,
ReservedKeyword(Region),
ArgumentsBeforeEquals(Region),
NotYetImplemented(String),
Todo,
Type(EType<'a>),
Pattern(EPattern<'a>),
Expr(EExpr<'a>, Position),
Header(EHeader<'a>),
Space(BadInputError),
NotEndOfFile(Position),
}
pub trait SpaceProblem: std::fmt::Debug {
fn space_problem(e: BadInputError, pos: Position) -> Self;
}
macro_rules! impl_space_problem {
($($name:ident $(< $lt:tt >)?),*) => {
$(
impl $(< $lt >)? SpaceProblem for $name $(< $lt >)? {
fn space_problem(e: BadInputError, pos: Position) -> Self {
Self::Space(e, pos)
}
}
)*
};
}
impl_space_problem! {
EExpect<'a>,
EExposes,
EExpr<'a>,
EHeader<'a>,
EIf<'a>,
EImport<'a>,
EParams<'a>,
EImports,
EImportParams<'a>,
EInParens<'a>,
EClosure<'a>,
EList<'a>,
EPackageEntry<'a>,
EPackages<'a>,
EPattern<'a>,
EProvides<'a>,
ERecord<'a>,
EReturn<'a>,
ERequires<'a>,
EString<'a>,
EType<'a>,
ETypeInParens<'a>,
ETypeRecord<'a>,
ETypeTagUnion<'a>,
ETypedIdent<'a>,
ETypeAbilityImpl<'a>,
EWhen<'a>,
EAbility<'a>,
PInParens<'a>,
PRecord<'a>,
PList<'a>
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EHeader<'a> {
Provides(EProvides<'a>, Position),
Params(EParams<'a>, Position),
Exposes(EExposes, Position),
Imports(EImports, Position),
Requires(ERequires<'a>, Position),
Packages(EPackages<'a>, Position),
Space(BadInputError, Position),
Start(Position),
ModuleName(Position),
AppName(EString<'a>, Position),
PackageName(EPackageName<'a>, Position),
PlatformName(EPackageName<'a>, Position),
IndentStart(Position),
InconsistentModuleName(Region),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EProvides<'a> {
Provides(Position),
Open(Position),
To(Position),
IndentProvides(Position),
IndentTo(Position),
IndentListStart(Position),
IndentPackage(Position),
ListStart(Position),
ListEnd(Position),
Identifier(Position),
Package(EPackageName<'a>, Position),
Space(BadInputError, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EParams<'a> {
Pattern(PRecord<'a>, Position),
BeforeArrow(Position),
Arrow(Position),
AfterArrow(Position),
Space(BadInputError, Position),
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum EExposes {
Exposes(Position),
Open(Position),
IndentExposes(Position),
IndentListStart(Position),
ListStart(Position),
ListEnd(Position),
Identifier(Position),
Space(BadInputError, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ERequires<'a> {
Requires(Position),
Open(Position),
IndentRequires(Position),
IndentListStart(Position),
ListStart(Position),
ListEnd(Position),
TypedIdent(ETypedIdent<'a>, Position),
Rigid(Position),
Space(BadInputError, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ETypedIdent<'a> {
Space(BadInputError, Position),
HasType(Position),
IndentHasType(Position),
Name(Position),
Type(EType<'a>, Position),
IndentType(Position),
Identifier(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EPackages<'a> {
Open(Position),
Space(BadInputError, Position),
Packages(Position),
IndentPackages(Position),
ListStart(Position),
ListEnd(Position),
IndentListStart(Position),
IndentListEnd(Position),
PackageEntry(EPackageEntry<'a>, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EPackageName<'a> {
BadPath(EString<'a>, Position),
Escapes(Position),
Multiline(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EPackageEntry<'a> {
BadPackage(EPackageName<'a>, Position),
Shorthand(Position),
Colon(Position),
IndentPackage(Position),
IndentPlatform(Position),
Platform(Position),
Space(BadInputError, Position),
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum EImports {
Open(Position),
Imports(Position),
IndentImports(Position),
IndentListStart(Position),
IndentListEnd(Position),
ListStart(Position),
ListEnd(Position),
Identifier(Position),
ExposingDot(Position),
ShorthandDot(Position),
Shorthand(Position),
ModuleName(Position),
Space(BadInputError, Position),
IndentSetStart(Position),
SetStart(Position),
SetEnd(Position),
TypedIdent(Position),
AsKeyword(Position),
StrLiteral(Position),
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum BadInputError {
HasTab,
HasMisplacedCarriageReturn,
HasAsciiControl,
BadUtf8,
}
impl<'a, T> SourceError<'a, T> {
pub fn new(problem: T, state: &State<'a>) -> Self {
Self {
problem,
bytes: state.original_bytes(),
}
}
pub fn map_problem<E>(self, f: impl FnOnce(T) -> E) -> SourceError<'a, E> {
SourceError {
problem: f(self.problem),
bytes: self.bytes,
}
}
pub fn into_file_error(self, filename: std::path::PathBuf) -> FileError<'a, T> {
FileError {
problem: self,
filename,
}
}
}
impl<'a> SyntaxError<'a> {
pub fn into_source_error(self, state: &State<'a>) -> SourceError<'a, SyntaxError<'a>> {
SourceError {
problem: self,
bytes: state.original_bytes(),
}
}
pub fn into_file_error(
self,
filename: std::path::PathBuf,
state: &State<'a>,
) -> FileError<'a, SyntaxError<'a>> {
self.into_source_error(state).into_file_error(filename)
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EExpr<'a> {
TrailingOperator(Position),
Start(Position),
End(Position),
BadExprEnd(Position),
Space(BadInputError, Position),
Dot(Position),
Access(Position),
UnaryNot(Position),
UnaryNegate(Position),
BadOperator(&'a str, Position),
DefMissingFinalExpr(Position),
DefMissingFinalExpr2(&'a EExpr<'a>, Position),
Type(EType<'a>, Position),
Pattern(&'a EPattern<'a>, Position),
Ability(EAbility<'a>, Position),
IndentDefBody(Position),
IndentEquals(Position),
IndentAnnotation(Position),
Equals(Position),
Colon(Position),
DoubleColon(Position),
Ident(Position),
ElmStyleFunction(Region, Position),
MalformedPattern(Position),
QualifiedTag(Position),
BackpassComma(Position),
BackpassArrow(Position),
BackpassContinue(Position),
DbgContinue(Position),
When(EWhen<'a>, Position),
If(EIf<'a>, Position),
Expect(EExpect<'a>, Position),
Dbg(EExpect<'a>, Position),
Import(EImport<'a>, Position),
Return(EReturn<'a>, Position),
Closure(EClosure<'a>, Position),
Underscore(Position),
Crash(Position),
Try(Position),
InParens(EInParens<'a>, Position),
Record(ERecord<'a>, Position),
RecordUpdateOldBuilderField(Region),
RecordUpdateIgnoredField(Region),
RecordBuilderOldBuilderField(Region),
// SingleQuote errors are folded into the EString
Str(EString<'a>, Position),
Number(ENumber, Position),
List(EList<'a>, Position),
IndentStart(Position),
IndentEnd(Position),
UnexpectedComma(Position),
UnexpectedTopLevelExpr(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ENumber {
End,
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EString<'a> {
Open(Position),
CodePtOpen(Position),
CodePtEnd(Position),
InvalidSingleQuote(ESingleQuote, Position),
Space(BadInputError, Position),
EndlessSingleLine(Position),
EndlessMultiLine(Position),
EndlessSingleQuote(Position),
UnknownEscape(Position),
Format(&'a EExpr<'a>, Position),
FormatEnd(Position),
MultilineInsufficientIndent(Position),
ExpectedDoubleQuoteGotSingleQuote(Position),
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ESingleQuote {
Empty,
TooLong,
InterpolationNotAllowed,
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ERecord<'a> {
End(Position),
Open(Position),
Prefix(Position),
Field(Position),
UnderscoreField(Position),
Colon(Position),
QuestionMark(Position),
Arrow(Position),
Ampersand(Position),
// TODO remove
Expr(&'a EExpr<'a>, Position),
Space(BadInputError, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EInParens<'a> {
End(Position),
Open(Position),
/// Empty parens, e.g. () is not allowed
Empty(Position),
///
Expr(&'a EExpr<'a>, Position),
///
Space(BadInputError, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EClosure<'a> {
Space(BadInputError, Position),
Start(Position),
Arrow(Position),
Comma(Position),
Arg(Position),
// TODO make EEXpr
Pattern(EPattern<'a>, Position),
Body(&'a EExpr<'a>, Position),
IndentArrow(Position),
IndentBody(Position),
IndentArg(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EList<'a> {
Open(Position),
End(Position),
Space(BadInputError, Position),
Expr(&'a EExpr<'a>, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EWhen<'a> {
Space(BadInputError, Position),
When(Position),
Is(Position),
Pattern(EPattern<'a>, Position),
Arrow(Position),
Bar(Position),
IfToken(Position),
IfGuard(&'a EExpr<'a>, Position),
Condition(&'a EExpr<'a>, Position),
Branch(&'a EExpr<'a>, Position),
IndentCondition(Position),
IndentPattern(Position),
IndentArrow(Position),
IndentBranch(Position),
IndentIfGuard(Position),
PatternAlignment(u32, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EAbility<'a> {
Space(BadInputError, Position),
Type(EType<'a>, Position),
DemandAlignment(i32, Position),
DemandName(Position),
DemandColon(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EIf<'a> {
Space(BadInputError, Position),
If(Position),
Then(Position),
Else(Position),
// TODO make EEXpr
Condition(&'a EExpr<'a>, Position),
ThenBranch(&'a EExpr<'a>, Position),
ElseBranch(&'a EExpr<'a>, Position),
IndentCondition(Position),
IndentIf(Position),
IndentThenToken(Position),
IndentElseToken(Position),
IndentThenBranch(Position),
IndentElseBranch(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EExpect<'a> {
Space(BadInputError, Position),
Dbg(Position),
Expect(Position),
Condition(&'a EExpr<'a>, Position),
Continuation(&'a EExpr<'a>, Position),
IndentCondition(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EReturn<'a> {
Space(BadInputError, Position),
Return(Position),
ReturnValue(&'a EExpr<'a>, Position),
IndentReturnValue(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EImport<'a> {
Import(Position),
IndentStart(Position),
PackageShorthand(Position),
PackageShorthandDot(Position),
ModuleName(Position),
Params(EImportParams<'a>, Position),
IndentAs(Position),
As(Position),
IndentAlias(Position),
Alias(Position),
LowercaseAlias(Region),
IndentExposing(Position),
Exposing(Position),
ExposingListStart(Position),
ExposedName(Position),
ExposingListEnd(Position),
IndentIngestedPath(Position),
IngestedPath(Position),
IndentIngestedName(Position),
IngestedName(Position),
IndentColon(Position),
Colon(Position),
IndentAnnotation(Position),
Annotation(EType<'a>, Position),
Space(BadInputError, Position),
EndNewline(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EImportParams<'a> {
Indent(Position),
Record(ERecord<'a>, Position),
RecordUpdateFound(Region),
RecordBuilderFound(Region),
RecordIgnoredFieldFound(Region),
Space(BadInputError, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EPattern<'a> {
Record(PRecord<'a>, Position),
List(PList<'a>, Position),
AsKeyword(Position),
AsIdentifier(Position),
Underscore(Position),
NotAPattern(Position),
Start(Position),
End(Position),
Space(BadInputError, Position),
PInParens(PInParens<'a>, Position),
NumLiteral(ENumber, Position),
IndentStart(Position),
IndentEnd(Position),
AsIndentStart(Position),
AccessorFunction(Position),
RecordUpdaterFunction(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum PRecord<'a> {
End(Position),
Open(Position),
Field(Position),
Colon(Position),
Optional(Position),
Pattern(&'a EPattern<'a>, Position),
Expr(&'a EExpr<'a>, Position),
Space(BadInputError, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum PList<'a> {
End(Position),
Open(Position),
Rest(Position),
Pattern(&'a EPattern<'a>, Position),
Space(BadInputError, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum PInParens<'a> {
Empty(Position),
End(Position),
Open(Position),
Pattern(&'a EPattern<'a>, Position),
Space(BadInputError, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum EType<'a> {
Space(BadInputError, Position),
UnderscoreSpacing(Position),
TRecord(ETypeRecord<'a>, Position),
TTagUnion(ETypeTagUnion<'a>, Position),
TInParens(ETypeInParens<'a>, Position),
TApply(ETypeApply, Position),
TInlineAlias(ETypeInlineAlias, Position),
TBadTypeVariable(Position),
TWildcard(Position),
TInferred(Position),
///
TStart(Position),
TEnd(Position),
TFunctionArgument(Position),
TWhereBar(Position),
TImplementsClause(Position),
TAbilityImpl(ETypeAbilityImpl<'a>, Position),
///
TIndentStart(Position),
TIndentEnd(Position),
TAsIndentStart(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ETypeRecord<'a> {
End(Position),
Open(Position),
Field(Position),
Colon(Position),
Optional(Position),
Type(&'a EType<'a>, Position),
Space(BadInputError, Position),
IndentOpen(Position),
IndentColon(Position),
IndentOptional(Position),
IndentEnd(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ETypeTagUnion<'a> {
End(Position),
Open(Position),
Type(&'a EType<'a>, Position),
Space(BadInputError, Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ETypeInParens<'a> {
/// e.g. (), which isn't a valid type
Empty(Position),
End(Position),
Open(Position),
///
Type(&'a EType<'a>, Position),
///
Space(BadInputError, Position),
///
IndentOpen(Position),
IndentEnd(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ETypeApply {
///
StartNotUppercase(Position),
End(Position),
Space(BadInputError, Position),
///
DoubleDot(Position),
TrailingDot(Position),
StartIsNumber(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ETypeInlineAlias {
NotAnAlias(Position),
Qualified(Position),
ArgumentNotLowercase(Position),
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ETypeAbilityImpl<'a> {
End(Position),
Open(Position),
Field(Position),
UnderscoreField(Position),
Colon(Position),
Arrow(Position),
Optional(Position),
Type(&'a EType<'a>, Position),
Space(BadInputError, Position),
Prefix(Position),
QuestionMark(Position),
Ampersand(Position),
Expr(&'a EExpr<'a>, Position),
IndentBar(Position),
IndentAmpersand(Position),
}
impl<'a> From<ERecord<'a>> for ETypeAbilityImpl<'a> {
fn from(e: ERecord<'a>) -> Self {
match e {
ERecord::End(p) => ETypeAbilityImpl::End(p),
ERecord::Open(p) => ETypeAbilityImpl::Open(p),
ERecord::Field(p) => ETypeAbilityImpl::Field(p),
ERecord::UnderscoreField(p) => ETypeAbilityImpl::UnderscoreField(p),
ERecord::Colon(p) => ETypeAbilityImpl::Colon(p),
ERecord::Arrow(p) => ETypeAbilityImpl::Arrow(p),
ERecord::Space(s, p) => ETypeAbilityImpl::Space(s, p),
ERecord::Prefix(p) => ETypeAbilityImpl::Prefix(p),
ERecord::QuestionMark(p) => ETypeAbilityImpl::QuestionMark(p),
ERecord::Ampersand(p) => ETypeAbilityImpl::Ampersand(p),
ERecord::Expr(e, p) => ETypeAbilityImpl::Expr(e, p),
}
}
}
#[derive(Debug)]
pub struct SourceError<'a, T> {
pub problem: T,
pub bytes: &'a [u8],
}
#[derive(Debug)]
pub struct FileError<'a, T> {
pub problem: SourceError<'a, T>,
pub filename: std::path::PathBuf,
}
pub trait Parser<'a, Output, Error> {
fn parse(
&self,
arena: &'a Bump,
state: State<'a>,
min_indent: u32,
) -> ParseResult<'a, Output, Error>;
#[cfg(not(feature = "parse_debug_trace"))]
#[inline(always)]
fn trace(self, _message: &'static str) -> Self
where
Self: Sized,
Output: std::fmt::Debug,
Error: std::fmt::Debug,
{
self
}
#[cfg(feature = "parse_debug_trace")]
fn trace(self, message: &'static str) -> Traced<'a, Output, Error, Self>
where
Self: Sized,
Output: std::fmt::Debug,
Error: std::fmt::Debug,
{
Traced {
parser: self,
message,
_phantom: Default::default(),
}
}
}
impl<'a, F, Output, Error> Parser<'a, Output, Error> for F
where
Error: 'a,
F: Fn(&'a Bump, State<'a>, u32) -> ParseResult<'a, Output, Error>,
{
fn parse(
&self,
arena: &'a Bump,
state: State<'a>,
min_indent: u32,
) -> ParseResult<'a, Output, Error> {
self(arena, state, min_indent)
}
}
#[cfg(feature = "parse_debug_trace")]
pub struct Traced<'a, O, E, P: Parser<'a, O, E>> {
parser: P,
message: &'static str,
_phantom: std::marker::PhantomData<&'a (O, E)>,
}
#[cfg(feature = "parse_debug_trace")]
impl<'a, O: std::fmt::Debug, E: std::fmt::Debug, P: Parser<'a, O, E>> Parser<'a, O, E>
for Traced<'a, O, E, P>
where
E: 'a,
{
fn parse(&self, arena: &'a Bump, state: State<'a>, min_indent: u32) -> ParseResult<'a, O, E> {
use std::cell::RefCell;
thread_local! {
pub static INDENT: RefCell<usize> = RefCell::new(0);
}
// This should be enough for anyone. Right? RIGHT?
let indent_text = "| ; : ! ".repeat(100);
let cur_indent = INDENT.with(|i| *i.borrow());
println!(
"{:<5?}:{:<2} {}{:<50}",
state.pos(),
min_indent,
&indent_text[..cur_indent * 2],
self.message
);
let previous_state = state.clone();
INDENT.with(|i| *i.borrow_mut() += 1);
let res = self.parser.parse(arena, state, min_indent);
INDENT.with(|i| *i.borrow_mut() = cur_indent);
let (progress, value, state) = match &res {
Ok((progress, result, state)) => (progress, Ok(result), state),
Err((progress, error)) => (progress, Err(error), &previous_state),
};
println!(
"{:<5?}:{:<2} {}{:<50} {:<15} {:?}",
state.pos(),
min_indent,
&indent_text[..cur_indent * 2],
self.message,
format!("{:?}", progress),
value
);
res
}
}
/// Allocates the output of the given parser and returns a reference to it.
/// This also happens if the given parser fails.
///
/// # Examples
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, allocated, word};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser_inner = word("hello", Problem::NotFound);
/// let alloc_parser = allocated(parser_inner);
///
/// // Success case
/// let (progress, output, state) = alloc_parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, &());
/// assert_eq!(state.pos(), Position::new(5));
///
/// // Error case
/// let (progress, err) = alloc_parser.parse(&arena, State::new("bye, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::NotFound(Position::zero()));
/// ```
pub fn allocated<'a, P, Val, Error>(parser: P) -> impl Parser<'a, &'a Val, Error>
where
Error: 'a,
P: Parser<'a, Val, Error>,
Val: 'a,
{
move |arena, state: State<'a>, min_indent: u32| {
let (progress, answer, state) = parser.parse(arena, state, min_indent)?;
Ok((progress, &*arena.alloc(answer), state))
}
}
/// Apply transform function to turn output of given parser into another parser.
/// Can be used to chain two parsers.
///
/// # Examples
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, and_then, word};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser1 = word("hello", Problem::NotFound);
/// let parser = and_then(parser1, move |p,b| word(", ", Problem::NotFound));
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos(), Position::new(7));
///
/// // Error case
/// let (progress, problem) = parser.parse(&arena, State::new("hello!! world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(problem, Problem::NotFound(Position::new(5)));
/// ```
pub fn and_then<'a, P1, P2, F, Before, After, Error>(
parser: P1,
transform: F,
) -> impl Parser<'a, After, Error>
where
P1: Parser<'a, Before, Error>,
P2: Parser<'a, After, Error>,
F: Fn(Progress, Before) -> P2,
Error: 'a,
{
move |arena, state, min_indent| {
parser
.parse(arena, state, min_indent)
.and_then(|(progress, output, next_state)| {
transform(progress, output).parse(arena, next_state, min_indent)
})
}
}
/// Creates a new parser that can change its output based on a function.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, then, word};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # OddChar(Position),
/// # }
/// # let arena = Bump::new();
/// let parser_inner = word("hello", Problem::NotFound);
///
/// let parser = then(parser_inner,
/// |arena, new_state, progress, output| {
/// // arbitrary check
/// if new_state.pos().offset % 2 == 0 {
/// Ok((progress, output, new_state))
/// } else {
/// Err((Progress::NoProgress, Problem::OddChar(new_state.pos())))
/// }
/// }
/// );
///
/// let actual = parser.parse(&arena, State::new("hello, world".as_bytes()), 0);
/// assert!(actual.is_err());
/// ```
pub fn then<'a, P1, F, Before, After, E>(parser: P1, transform: F) -> impl Parser<'a, After, E>
where
P1: Parser<'a, Before, E>,
After: 'a,
E: 'a,
F: Fn(&'a Bump, State<'a>, Progress, Before) -> ParseResult<'a, After, E>,
{
move |arena, state, min_indent| {
parser
.parse(arena, state, min_indent)
.and_then(|(progress, output, next_state)| {
transform(arena, next_state, progress, output)
})
}
}
/// Matches a word/string exactly, useful when finding a keyword.
/// This only matches if the next char is whitespace, the start of a comment, or the end of a line.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, keyword};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = keyword("when", Problem::NotFound);
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("when".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos().offset, 4);
///
/// // Error case
/// let (progress, err) = parser.parse(&arena, State::new("whence".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::NotFound(Position::zero()));
/// ```
pub fn keyword<'a, ToError, E>(
keyword_str: &'static str,
if_error: ToError,
) -> impl Parser<'a, (), E>
where
ToError: Fn(Position) -> E,
E: 'a,
{
move |_, mut state: State<'a>, _min_indent| {
let width = keyword_str.len();
if !state.bytes().starts_with(keyword_str.as_bytes()) {
return Err((NoProgress, if_error(state.pos())));
}
// the next character should not be an identifier character
// to prevent treating `whence` or `iffy` as keywords
match state.bytes().get(width) {
Some(
b' ' | b'#' | b'\n' | b'\r' | b'\t' | b',' | b'(' | b')' | b'[' | b']' | b'{'
| b'}' | b'"' | b'\'' | b'/' | b'\\' | b'+' | b'*' | b'%' | b'^' | b'&' | b'|'
| b'<' | b'>' | b'=' | b'!' | b'~' | b'`' | b';' | b':' | b'?' | b'.' | b'@' | b'-',
) => {
state = state.advance(width);
Ok((MadeProgress, (), state))
}
None => {
state = state.advance(width);
Ok((MadeProgress, (), state))
}
Some(_) => Err((NoProgress, if_error(state.pos()))),
}
}
}
/// Parse zero or more values separated by a delimiter (e.g. a comma) whose
/// values are discarded
pub fn sep_by0<'a, P, D, Val, Error>(
delimiter: D,
parser: P,
) -> impl Parser<'a, Vec<'a, Val>, Error>
where
D: Parser<'a, (), Error>,
P: Parser<'a, Val, Error>,
Error: 'a,
{
move |arena, state: State<'a>, min_indent: u32| {
let original_state = state.clone();
let start_bytes_len = state.bytes().len();
match parser.parse(arena, state, min_indent) {
Ok((elem_progress, first_output, next_state)) => {
// in practice, we want elements to make progress
debug_assert_eq!(elem_progress, MadeProgress);
let mut state = next_state;
let mut buf = Vec::with_capacity_in(1, arena);
buf.push(first_output);
loop {
match delimiter.parse(arena, state.clone(), min_indent) {
Ok((_, (), next_state)) => {
// If the delimiter passed, check the element parser.
match parser.parse(arena, next_state.clone(), min_indent) {
Ok((element_progress, next_output, next_state)) => {
// in practice, we want elements to make progress
debug_assert_eq!(element_progress, MadeProgress);
state = next_state;
buf.push(next_output);
}
Err((_, fail)) => {
// If the delimiter parsed, but the following
// element did not, that's a fatal error.
let progress = Progress::from_lengths(
start_bytes_len,
next_state.bytes().len(),
);
return Err((progress, fail));
}
}
}
Err((delim_progress, fail)) => match delim_progress {
MadeProgress => return Err((MadeProgress, fail)),
NoProgress => return Ok((NoProgress, buf, state)),
},
}
}
}
Err((element_progress, fail)) => match element_progress {
MadeProgress => Err((MadeProgress, fail)),
NoProgress => Ok((NoProgress, Vec::new_in(arena), original_state)),
},
}
}
}
/// Parse zero or more values separated by a delimiter (e.g. a comma)
/// with an optional trailing delimiter whose values are discarded
pub fn trailing_sep_by0<'a, P, D, Val, Error>(
delimiter: D,
parser: P,
) -> impl Parser<'a, Vec<'a, Val>, Error>
where
D: Parser<'a, (), Error>,
P: Parser<'a, Val, Error>,
Error: 'a,
{
move |arena, state: State<'a>, min_indent: u32| {
let original_state = state.clone();
let start_bytes_len = state.bytes().len();
match parser.parse(arena, state, min_indent) {
Ok((progress, first_output, next_state)) => {
// in practice, we want elements to make progress
debug_assert_eq!(progress, MadeProgress);
let mut state = next_state;
let mut buf = Vec::with_capacity_in(1, arena);
buf.push(first_output);
loop {
match delimiter.parse(arena, state.clone(), min_indent) {
Ok((_, (), next_state)) => {
// If the delimiter passed, check the element parser.
match parser.parse(arena, next_state.clone(), min_indent) {
Ok((element_progress, next_output, next_state)) => {
// in practice, we want elements to make progress
debug_assert_eq!(element_progress, MadeProgress);
state = next_state;
buf.push(next_output);
}
Err((_, _fail)) => {
// If the delimiter parsed, but the following
// element did not, that means we saw a trailing comma
let progress = Progress::from_lengths(
start_bytes_len,
next_state.bytes().len(),
);
return Ok((progress, buf, next_state));
}
}
}
Err((delim_progress, fail)) => match delim_progress {
MadeProgress => return Err((MadeProgress, fail)),
NoProgress => return Ok((NoProgress, buf, state)),
},
}
}
}
Err((element_progress, fail)) => match element_progress {
MadeProgress => Err((MadeProgress, fail)),
NoProgress => Ok((NoProgress, Vec::new_in(arena), original_state)),
},
}
}
}
/// Parse one or more values separated by a delimiter (e.g. a comma) whose
/// values are discarded
pub fn sep_by1<'a, P, D, Val, Error>(
delimiter: D,
parser: P,
) -> impl Parser<'a, Vec<'a, Val>, Error>
where
D: Parser<'a, (), Error>,
P: Parser<'a, Val, Error>,
Error: 'a,
{
move |arena, state: State<'a>, min_indent: u32| {
let start_bytes_len = state.bytes().len();
match parser.parse(arena, state, min_indent) {
Ok((progress, first_output, next_state)) => {
debug_assert_eq!(progress, MadeProgress);
let mut state = next_state;
let mut buf = Vec::with_capacity_in(1, arena);
buf.push(first_output);
loop {
let old_state = state.clone();
match delimiter.parse(arena, state, min_indent) {
Ok((_, (), next_state)) => {
// If the delimiter passed, check the element parser.
match parser.parse(arena, next_state, min_indent) {
Ok((_, next_output, next_state)) => {
state = next_state;
buf.push(next_output);
}
Err((_, fail)) => {
return Err((MadeProgress, fail));
}
}
}
Err((delim_progress, fail)) => {
match delim_progress {
MadeProgress => {
// fail if the delimiter made progress
return Err((MadeProgress, fail));
}
NoProgress => {
let progress = Progress::from_lengths(
start_bytes_len,
old_state.bytes().len(),
);
return Ok((progress, buf, old_state));
}
}
}
}
}
}
Err((fail_progress, fail)) => Err((fail_progress, fail)),
}
}
}
/// Parse one or more values separated by a delimiter (e.g. a comma) whose
/// values are discarded
pub fn sep_by1_e<'a, P, V, D, Val, Error>(
delimiter: D,
parser: P,
to_element_error: V,
) -> impl Parser<'a, Vec<'a, Val>, Error>
where
D: Parser<'a, (), Error>,
P: Parser<'a, Val, Error>,
V: Fn(Position) -> Error,
Error: 'a,
{
move |arena, state: State<'a>, min_indent: u32| {
let original_state = state.clone();
let start_bytes_len = state.bytes().len();
match parser.parse(arena, state, min_indent) {
Ok((progress, first_output, next_state)) => {
debug_assert_eq!(progress, MadeProgress);
let mut state = next_state;
let mut buf = Vec::with_capacity_in(1, arena);
buf.push(first_output);
loop {
let old_state = state.clone();
match delimiter.parse(arena, state, min_indent) {
Ok((_, (), next_state)) => {
// If the delimiter passed, check the element parser.
match parser.parse(arena, next_state.clone(), min_indent) {
Ok((_, next_output, next_state)) => {
state = next_state;
buf.push(next_output);
}
Err((MadeProgress, fail)) => {
return Err((MadeProgress, fail));
}
Err((NoProgress, _fail)) => {
return Err((NoProgress, to_element_error(next_state.pos())));
}
}
}
Err((delim_progress, fail)) => {
match delim_progress {
MadeProgress => {
// fail if the delimiter made progress
return Err((MadeProgress, fail));
}
NoProgress => {
let progress = Progress::from_lengths(
start_bytes_len,
old_state.bytes().len(),
);
return Ok((progress, buf, old_state));
}
}
}
}
}
}
Err((MadeProgress, fail)) => Err((MadeProgress, fail)),
Err((NoProgress, _fail)) => Err((NoProgress, to_element_error(original_state.pos()))),
}
}
}
/// Make the given parser optional, it can complete or not consume anything,
/// but it can't error with progress made.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, optional, word};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = optional(word("hello", Problem::NotFound));
///
/// // Parser completed case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, Some(()));
/// assert_eq!(state.pos().offset, 5);
///
/// // No progress case
/// let (progress, output, state) = parser.parse(&arena, State::new("bye, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(output, None);
/// assert_eq!(state.pos().offset, 0);
/// ```
pub fn optional<'a, P, T, E>(parser: P) -> impl Parser<'a, Option<T>, E>
where
P: Parser<'a, T, E>,
E: 'a,
{
move |arena: &'a Bump, state: State<'a>, min_indent: u32| {
// We have to clone this because if the optional parser fails,
// we need to revert back to the original state.
let original_state = state.clone();
match parser.parse(arena, state, min_indent) {
Ok((progress, out1, state)) => Ok((progress, Some(out1), state)),
Err((MadeProgress, e)) => Err((MadeProgress, e)),
Err((NoProgress, _)) => Ok((NoProgress, None, original_state)),
}
}
}
// MACRO COMBINATORS
//
// Using some combinators together results in combinatorial type explosion,
// this takes forever to compile. Using macros instead avoids this!
/// Wraps the output of the given parser in a [`Loc`](../roc_region/all/struct.Loc.html) struct,
/// to provide location information.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, loc};
/// # use roc_region::all::{Loc, Position};
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// # fn foo<'a>(arena: &'a Bump) {
/// let parser = loc(word("hello", Problem::NotFound));
///
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, Loc::new(0, 5, ()));
/// assert_eq!(state.pos().offset, 5);
/// # }
/// # foo(&arena);
/// ```
pub fn loc<'a, Output, E: 'a>(
parser: impl Parser<'a, Output, E>,
) -> impl Parser<'a, Loc<Output>, E> {
move |arena, state: crate::state::State<'a>, min_indent: u32| {
let start = state.pos();
match parser.parse(arena, state, min_indent) {
Ok((progress, value, state)) => {
let end = state.pos();
let region = Region::new(start, end);
Ok((progress, Loc { region, value }, state))
}
Err(err) => Err(err),
}
}
}
/// If the first one parses, ignore its output and move on to parse with the second one.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, skip_first};
/// # use roc_parse::ident::lowercase_ident;
/// # use bumpalo::Bump;
/// # let arena = Bump::new();
/// # fn foo<'a>(arena: &'a Bump) {
/// let parser = skip_first(
/// word("hello, ", |_| ()),
/// lowercase_ident()
/// );
///
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, "world");
/// assert_eq!(state.pos().offset, 12);
/// # }
/// # foo(&arena);
/// ```
pub fn skip_first<'a, P1, First, P2, Second, E>(p1: P1, p2: P2) -> impl Parser<'a, Second, E>
where
P1: Parser<'a, First, E>,
P2: Parser<'a, Second, E>,
E: 'a,
{
move |arena, state: crate::state::State<'a>, min_indent: u32| match p1
.parse(arena, state, min_indent)
{
Ok((p1, _, state)) => match p2.parse(arena, state, min_indent) {
Ok((p2, out2, state)) => Ok((p1.or(p2), out2, state)),
Err((p2, fail)) => Err((p1.or(p2), fail)),
},
Err((progress, fail)) => Err((progress, fail)),
}
}
/// If the first one parses, parse the second one; if it also parses, use the
/// output from the first one.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, skip_second};
/// # use roc_parse::ident::lowercase_ident;
/// # use bumpalo::Bump;
/// # let arena = Bump::new();
/// # fn foo<'a>(arena: &'a Bump) {
/// let parser = skip_second(
/// lowercase_ident(),
/// word(", world", |_| ())
/// );
///
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, "hello");
/// assert_eq!(state.pos().offset, 12);
/// # }
/// # foo(&arena);
/// ```
pub fn skip_second<'a, P1, First, P2, Second, E>(p1: P1, p2: P2) -> impl Parser<'a, First, E>
where
E: 'a,
P1: Parser<'a, First, E>,
P2: Parser<'a, Second, E>,
{
move |arena, state: crate::state::State<'a>, min_indent: u32| match p1
.parse(arena, state, min_indent)
{
Ok((p1, out1, state)) => match p2.parse(arena, state, min_indent) {
Ok((p2, _, state)) => Ok((p1.or(p2), out1, state)),
Err((p2, fail)) => Err((p1.or(p2), fail)),
},
Err((progress, fail)) => Err((progress, fail)),
}
}
pub fn collection_inner<'a, Elem: 'a + crate::ast::Spaceable<'a> + Clone, E: 'a + SpaceProblem>(
elem: impl Parser<'a, Loc<Elem>, E> + 'a,
delimiter: impl Parser<'a, (), E>,
space_before: impl Fn(&'a Elem, &'a [crate::ast::CommentOrNewline<'a>]) -> Elem,
) -> impl Parser<'a, crate::ast::Collection<'a, Loc<Elem>>, E> {
map_with_arena(
and(
and(
crate::blankspace::spaces(),
trailing_sep_by0(
delimiter,
crate::blankspace::spaces_before_optional_after(elem),
),
),
crate::blankspace::spaces(),
),
#[allow(clippy::type_complexity)]
move |arena: &'a bumpalo::Bump,
out: (
(
&'a [crate::ast::CommentOrNewline<'a>],
bumpalo::collections::Vec<'a, Loc<Elem>>,
),
&'a [crate::ast::CommentOrNewline<'a>],
)| {
let ((spaces, mut parsed_elems), mut final_comments) = out;
if !spaces.is_empty() {
if let Some(first) = parsed_elems.first_mut() {
first.value = space_before(arena.alloc(first.value.clone()), spaces);
} else {
debug_assert!(final_comments.is_empty());
final_comments = spaces;
}
}
crate::ast::Collection::with_items_and_comments(
arena,
parsed_elems.into_bump_slice(),
final_comments,
)
},
)
}
pub fn collection_trailing_sep_e<
'a,
Elem: 'a + crate::ast::Spaceable<'a> + Clone,
E: 'a + SpaceProblem,
>(
opening_brace: impl Parser<'a, (), E>,
elem: impl Parser<'a, Loc<Elem>, E> + 'a,
delimiter: impl Parser<'a, (), E>,
closing_brace: impl Parser<'a, (), E>,
space_before: impl Fn(&'a Elem, &'a [crate::ast::CommentOrNewline<'a>]) -> Elem,
) -> impl Parser<'a, crate::ast::Collection<'a, Loc<Elem>>, E> {
between(
opening_brace,
reset_min_indent(collection_inner(elem, delimiter, space_before)),
closing_brace,
)
}
/// Creates a parser that always succeeds with the given argument as output.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, succeed};
/// # use bumpalo::Bump;
/// # let arena = Bump::new();
/// # fn foo<'a>(arena: &'a Bump) {
/// let parser = succeed("different");
///
/// let (progress, output, state) = Parser::<&'a str,()>::parse(&parser, &arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(output, "different");
/// assert_eq!(state.pos().offset, 0);
/// # }
/// # foo(&arena);
/// ```
pub fn succeed<'a, T: Clone, E: 'a>(value: T) -> impl Parser<'a, T, E> {
move |_arena: &'a bumpalo::Bump, state: crate::state::State<'a>, _min_indent: u32| {
Ok((NoProgress, value.clone(), state))
}
}
/// Creates a parser that always fails.
/// If the given parser succeeds, the error is customized with the given function.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, fail_when};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # OtherProblem(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = fail_when(Problem::OtherProblem, word("hello", Problem::NotFound));
///
/// // When given parser succeeds:
/// let (progress, err) = Parser::<(), Problem>::parse(&parser, &arena, State::new("hello, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(err, Problem::OtherProblem(Position::new(0)));
///
/// // When given parser errors:
/// let (progress, err) = Parser::<(), Problem>::parse(&parser, &arena, State::new("bye, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::NotFound(Position::new(0)));
/// ```
pub fn fail_when<'a, T, T2, E, F, P>(f: F, p: P) -> impl Parser<'a, T, E>
where
T: 'a,
T2: 'a,
E: 'a,
F: Fn(Position) -> E,
P: Parser<'a, T2, E>,
{
move |arena: &'a bumpalo::Bump, state: State<'a>, min_indent: u32| {
let original_state = state.clone();
match p.parse(arena, state, min_indent) {
Ok((_, _, _)) => Err((MadeProgress, f(original_state.pos()))),
Err((progress, err)) => Err((progress, err)),
}
}
}
/// Creates a parser that always fails using the given error function.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, fail};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = fail(Problem::NotFound);
///
/// let (progress, err) = Parser::<(), Problem>::parse(&parser, &arena, State::new("hello, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::NotFound(Position::new(0)));
/// ```
pub fn fail<'a, T, E, F>(f: F) -> impl Parser<'a, T, E>
where
T: 'a,
E: 'a,
F: Fn(Position) -> E,
{
move |_arena: &'a bumpalo::Bump, state: State<'a>, _min_indent: u32| {
Err((NoProgress, f(state.pos())))
}
}
/// Creates a parser that fails if the next byte is the given byte.
pub fn error_on_byte<'a, T, E, F>(byte_to_match: u8, to_error: F) -> impl Parser<'a, T, E>
where
T: 'a,
E: 'a,
F: Fn(Position) -> E,
{
debug_assert_ne!(byte_to_match, b'\n');
move |_arena: &'a Bump, state: State<'a>, _min_indent: u32| match state.bytes().first() {
Some(x) if *x == byte_to_match => Err((MadeProgress, to_error(state.pos()))),
_ => Err((NoProgress, to_error(state.pos()))),
}
}
/// Runs two parsers in succession. If both parsers succeed, the output is a tuple of both outputs.
/// Both parsers must have the same error type.
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, and, word};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser1 = word("hello", Problem::NotFound);
/// let parser2 = word(", ", Problem::NotFound);
/// let parser = and(parser1, parser2);
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ((),()));
/// assert_eq!(state.pos(), Position::new(7));
///
/// // Error case
/// let (progress, err) = parser.parse(&arena, State::new("hello!! world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(err, Problem::NotFound(Position::new(5)));
/// ```
pub fn and<'a, Output1, Output2, E: 'a>(
p1: impl Parser<'a, Output1, E>,
p2: impl Parser<'a, Output2, E>,
) -> impl Parser<'a, (Output1, Output2), E> {
move |arena: &'a bumpalo::Bump, state: crate::state::State<'a>, min_indent: u32| match p1
.parse(arena, state, min_indent)
{
Ok((p1, out1, state)) => match p2.parse(arena, state, min_indent) {
Ok((p2, out2, state)) => Ok((p1.or(p2), (out1, out2), state)),
Err((p2, fail)) => Err((p1.or(p2), fail)),
},
Err((progress, fail)) => Err((progress, fail)),
}
}
/// Take as input something that looks like a struct literal where values are parsers
/// and return a parser that runs each parser and returns a struct literal with the
/// results.
#[macro_export]
macro_rules! record {
($name:ident $(:: $name_ext:ident)* { $($field:ident: $parser:expr),* $(,)? }) => {
move |arena: &'a bumpalo::Bump, state: $crate::state::State<'a>, min_indent: u32| {
let mut state = state;
let mut progress = NoProgress;
$(
let (new_progress, $field, new_state) = $parser.parse(arena, state, min_indent)?;
state = new_state;
progress = progress.or(new_progress);
)*
Ok((progress, $name $(:: $name_ext)* { $($field),* }, state))
}
};
}
/// Similar to [`skip_first`], but we modify the `min_indent` of the second
/// parser (`parser`) to be 1 greater than the `line_indent()` at the start of
/// the first parser (`before`).
pub fn indented_seq_skip_first<'a, O, E: 'a>(
before: impl Parser<'a, (), E>,
parser: impl Parser<'a, O, E>,
) -> impl Parser<'a, O, E> {
move |arena: &'a bumpalo::Bump, state: crate::state::State<'a>, _min_indent: u32| {
let start_indent = state.line_indent();
// TODO: we should account for min_indent here, but this doesn't currently work
// because min_indent is sometimes larger than it really should be, which is in turn
// due to uses of `increment_indent`.
//
// let p1_indent = std::cmp::max(start_indent, min_indent);
let p1_indent = start_indent;
let p2_indent = p1_indent + 1;
match before.parse(arena, state, p1_indent) {
Ok((p1, (), state)) => match parser.parse(arena, state, p2_indent) {
Ok((p2, out2, state)) => Ok((p1.or(p2), out2, state)),
Err((p2, fail)) => Err((p1.or(p2), fail)),
},
Err((progress, fail)) => Err((progress, fail)),
}
}
}
/// Similar to `and`, but we modify the min_indent of the second parser to be
/// 1 greater than the line_indent() at the start of the first parser.
pub fn indented_seq<'a, Output1, Output2, E: 'a>(
p1: impl Parser<'a, Output1, E>,
p2: impl Parser<'a, Output2, E>,
) -> impl Parser<'a, (Output1, Output2), E> {
move |arena: &'a bumpalo::Bump, state: crate::state::State<'a>, _min_indent: u32| {
let start_indent = state.line_indent();
// TODO: we should account for min_indent here, but this doesn't currently work
// because min_indent is sometimes larger than it really should be, which is in turn
// due to uses of `increment_indent`.
//
// let p1_indent = std::cmp::max(start_indent, min_indent);
let p1_indent = start_indent;
let p2_indent = p1_indent + 1;
match p1.parse(arena, state, p1_indent) {
Ok((p1, out1, state)) => match p2.parse(arena, state, p2_indent) {
Ok((p2, out2, state)) => Ok((p1.or(p2), (out1, out2), state)),
Err((p2, fail)) => Err((p1.or(p2), fail)),
},
Err((progress, fail)) => Err((progress, fail)),
}
}
}
/// Similar to [`and`], but we modify the `min_indent` of the second parser to be
/// 1 greater than the `column()` at the start of the first parser.
pub fn absolute_indented_seq<'a, Output1, Output2, E: 'a>(
p1: impl Parser<'a, Output1, E>,
p2: impl Parser<'a, Output2, E>,
) -> impl Parser<'a, (Output1, Output2), E> {
move |arena: &'a bumpalo::Bump, state: crate::state::State<'a>, _min_indent: u32| {
let start_indent = state.column();
let p1_indent = start_indent;
let p2_indent = p1_indent + 1;
match p1.parse(arena, state, p1_indent) {
Ok((p1, out1, state)) => match p2.parse(arena, state, p2_indent) {
Ok((p2, out2, state)) => Ok((p1.or(p2), (out1, out2), state)),
Err((p2, fail)) => Err((p1.or(p2), fail)),
},
Err((progress, fail)) => Err((progress, fail)),
}
}
}
/// Returns the result of the first parser that makes progress, even if it failed.
/// If no parsers make progress, the last parser's result is returned.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, byte};
/// # use roc_region::all::Position;
/// # use roc_parse::one_of;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// # fn foo<'a>(arena: &'a Bump) {
/// let parser1 = one_of!(
/// word("hello", Problem::NotFound),
/// byte(b'h', Problem::NotFound)
/// );
/// let (progress, output, state) = parser1.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos().offset, 5);
///
/// let parser2 = one_of!(
/// // swapped the order of the parsers
/// byte(b'h', Problem::NotFound),
/// word("hello", Problem::NotFound)
/// );
/// let (progress, output, state) = parser2.parse(&arena, State::new("hello! world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos().offset, 1);
/// # }
/// # foo(&arena);
/// ```
#[macro_export]
macro_rules! one_of {
($p1:expr, $p2:expr) => {
move |arena: &'a bumpalo::Bump, state: $crate::state::State<'a>, min_indent: u32| {
let original_state = state.clone();
match $p1.parse(arena, state, min_indent) {
valid @ Ok(_) => valid,
Err((MadeProgress, fail)) => Err((MadeProgress, fail)),
Err((NoProgress, _)) => $p2.parse(arena, original_state, min_indent),
}
}
};
($p1:expr, $($others:expr),+) => {
one_of!($p1, one_of!($($others),+))
};
($p1:expr, $($others:expr),+ $(,)?) => {
one_of!($p1, $($others),+)
};
}
pub fn reset_min_indent<'a, P, T, X: 'a>(parser: P) -> impl Parser<'a, T, X>
where
P: Parser<'a, T, X>,
{
move |arena, state, _min_indent| parser.parse(arena, state, 0)
}
pub fn set_min_indent<'a, P, T, X: 'a>(min_indent: u32, parser: P) -> impl Parser<'a, T, X>
where
P: Parser<'a, T, X>,
{
move |arena, state, _m| parser.parse(arena, state, min_indent)
}
pub fn increment_min_indent<'a, P, T, X: 'a>(parser: P) -> impl Parser<'a, T, X>
where
P: Parser<'a, T, X>,
{
move |arena, state, min_indent| parser.parse(arena, state, min_indent + 1)
}
pub fn line_min_indent<'a, P, T, X: 'a>(parser: P) -> impl Parser<'a, T, X>
where
P: Parser<'a, T, X>,
{
move |arena, state: State<'a>, min_indent| {
let min_indent = std::cmp::max(state.line_indent(), min_indent);
parser.parse(arena, state, min_indent)
}
}
pub fn absolute_column_min_indent<'a, P, T, X: 'a>(parser: P) -> impl Parser<'a, T, X>
where
P: Parser<'a, T, X>,
{
move |arena, state: State<'a>, _min_indent| {
let min_indent = state.column() + 1;
parser.parse(arena, state, min_indent)
}
}
/// Transforms a possible error, like `map_err` in Rust.
/// It has no effect if the given parser succeeds.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, specialize_err};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # Other(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = specialize_err(
/// |_prev_err, pos| Problem::Other(pos),
/// word("bye", Problem::NotFound)
/// );
///
/// let (progress, err) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::Other(Position::new(0)));
/// ```
pub fn specialize_err<'a, F, P, T, X, Y>(map_error: F, parser: P) -> impl Parser<'a, T, Y>
where
F: Fn(X, Position) -> Y,
P: Parser<'a, T, X>,
Y: 'a,
{
move |a, state: State<'a>, min_indent| {
let original_state = state.clone();
match parser.parse(a, state, min_indent) {
Ok(t) => Ok(t),
Err((p, error)) => Err((p, map_error(error, original_state.pos()))),
}
}
}
/// Transforms a possible error, like `map_err` in Rust.
/// Similar to [`specialize_err`], but the error is arena allocated, and the
/// mapping function receives a reference to the error.
/// It has no effect if the inner parser succeeds.
///
/// # Examples
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, specialize_err_ref};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # Other(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = specialize_err_ref(
/// |_prev_err, pos| Problem::Other(pos),
/// word("bye", Problem::NotFound)
/// );
///
/// let (progress, err) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::Other(Position::new(0)));
/// ```
pub fn specialize_err_ref<'a, F, P, T, X, Y>(map_error: F, parser: P) -> impl Parser<'a, T, Y>
where
F: Fn(&'a X, Position) -> Y,
P: Parser<'a, T, X>,
Y: 'a,
X: 'a,
{
move |a, state: State<'a>, min_indent| {
let original_state = state.clone();
match parser.parse(a, state, min_indent) {
Ok(t) => Ok(t),
Err((p, error)) => Err((p, map_error(a.alloc(error), original_state.pos()))),
}
}
}
/// Matches an entire `str` and moves the state's position forward if it succeeds.
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = word("hello", Problem::NotFound);
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos(), Position::new(5));
///
/// // Error case
/// let (progress, problem) = parser.parse(&arena, State::new("bye, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(problem, Problem::NotFound(Position::zero()));
/// ```
pub fn word<'a, ToError, E>(word: &'static str, to_error: ToError) -> impl Parser<'a, (), E>
where
ToError: Fn(Position) -> E,
E: 'a,
{
debug_assert!(!word.contains('\n'));
move |_arena: &'a Bump, state: State<'a>, _min_indent: u32| {
if state.bytes().starts_with(word.as_bytes()) {
let state = state.advance(word.len());
Ok((MadeProgress, (), state))
} else {
Err((NoProgress, to_error(state.pos())))
}
}
}
/// Matches a single `u8` and moves the state's position forward if it succeeds.
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, byte};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = byte(b'h', Problem::NotFound);
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos(), Position::new(1));
///
/// // Error case
/// let (progress, problem) = parser.parse(&arena, State::new("bye, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(problem, Problem::NotFound(Position::zero()));
/// ```
pub fn byte<'a, ToError, E>(byte_to_match: u8, to_error: ToError) -> impl Parser<'a, (), E>
where
ToError: Fn(Position) -> E,
E: 'a,
{
debug_assert_ne!(byte_to_match, b'\n');
move |_arena: &'a Bump, state: State<'a>, _min_indent: u32| match state.bytes().first() {
Some(x) if *x == byte_to_match => {
let state = state.advance(1);
Ok((MadeProgress, (), state))
}
_ => Err((NoProgress, to_error(state.pos()))),
}
}
/// Matches a single `u8` and moves the state's position forward if it succeeds.
/// This parser will fail if it is a lower indentation level than it should be.
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, byte, byte_indent};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # WrongIndentLevel(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = byte_indent(b'h', Problem::WrongIndentLevel);
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos(), Position::new(1));
///
/// // Error case
/// let state = State::new(" hello, world".as_bytes());
/// let _ = byte(b' ', Problem::NotFound).parse(&arena, state.clone(), 0).unwrap();
/// let (progress, problem) = parser.parse(&arena, state, 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(problem, Problem::WrongIndentLevel(Position::zero()));
/// ```
pub fn byte_indent<'a, ToError, E>(byte_to_match: u8, to_error: ToError) -> impl Parser<'a, (), E>
where
ToError: Fn(Position) -> E,
E: 'a,
{
debug_assert_ne!(byte_to_match, b'\n');
move |_arena: &'a Bump, state: State<'a>, min_indent: u32| {
if min_indent > state.column() {
return Err((NoProgress, to_error(state.pos())));
}
match state.bytes().first() {
Some(x) if *x == byte_to_match => {
let state = state.advance(1);
Ok((MadeProgress, (), state))
}
_ => Err((NoProgress, to_error(state.pos()))),
}
}
}
/// Matches two `u8` in a row.
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, two_bytes};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = two_bytes(b'h', b'e', Problem::NotFound);
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos(), Position::new(2));
///
/// // Error case
/// let (progress, problem) = parser.parse(&arena, State::new("hi, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(problem, Problem::NotFound(Position::zero()));
/// ```
pub fn two_bytes<'a, ToError, E>(
byte_1: u8,
byte_2: u8,
to_error: ToError,
) -> impl Parser<'a, (), E>
where
ToError: Fn(Position) -> E,
E: 'a,
{
debug_assert_ne!(byte_1, b'\n');
debug_assert_ne!(byte_2, b'\n');
let needle = [byte_1, byte_2];
move |_arena: &'a Bump, state: State<'a>, _min_indent: u32| {
if state.bytes().starts_with(&needle) {
let state = state.advance(2);
Ok((MadeProgress, (), state))
} else {
Err((NoProgress, to_error(state.pos())))
}
}
}
/// Matches three `u8` in a row.
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, three_bytes};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = three_bytes(b'h', b'e', b'l', Problem::NotFound);
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos(), Position::new(3));
///
/// // Error case
/// let (progress, err) = parser.parse(&arena, State::new("hi, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::NotFound(Position::zero()));
/// ```
pub fn three_bytes<'a, ToError, E>(
byte_1: u8,
byte_2: u8,
byte_3: u8,
to_error: ToError,
) -> impl Parser<'a, (), E>
where
ToError: Fn(Position) -> E,
E: 'a,
{
debug_assert_ne!(byte_1, b'\n');
debug_assert_ne!(byte_2, b'\n');
debug_assert_ne!(byte_3, b'\n');
let needle = [byte_1, byte_2, byte_3];
move |_arena: &'a Bump, state: State<'a>, _min_indent: u32| {
if state.bytes().starts_with(&needle) {
let state = state.advance(3);
Ok((MadeProgress, (), state))
} else {
Err((NoProgress, to_error(state.pos())))
}
}
}
#[macro_export]
macro_rules! byte_check_indent {
($byte_to_match:expr, $problem:expr, $min_indent:expr, $indent_problem:expr) => {
$crate::parser::and(
byte($byte_to_match, $problem),
$crate::parser::check_indent($min_indent, $indent_problem),
)
};
}
/// transform the `Ok` result of a parser
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, map};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = map(
/// word("hello", Problem::NotFound),
/// |_output| "new output!"
/// );
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, "new output!");
/// assert_eq!(state.pos(), Position::new(5));
///
/// // Error case
/// let (progress, err) = parser.parse(&arena, State::new("bye, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::NotFound(Position::zero()));
/// ```
pub fn map<'a, Output, MappedOutput, E: 'a>(
parser: impl Parser<'a, Output, E>,
transform: impl Fn(Output) -> MappedOutput,
) -> impl Parser<'a, MappedOutput, E> {
move |arena, state, min_indent| {
parser
.parse(arena, state, min_indent)
.map(|(progress, output, next_state)| (progress, transform(output), next_state))
}
}
/// Applies the parser as many times as possible.
/// This parser will only fail if the given parser makes partial progress.
pub fn zero_or_more<'a, Output, E: 'a>(
parser: impl Parser<'a, Output, E>,
) -> impl Parser<'a, bumpalo::collections::Vec<'a, Output>, E> {
move |arena, state: State<'a>, min_indent: u32| {
let original_state = state.clone();
let start_bytes_len = state.bytes().len();
match parser.parse(arena, state, min_indent) {
Ok((_, first_output, next_state)) => {
let mut state = next_state;
let mut buf = Vec::with_capacity_in(1, arena);
buf.push(first_output);
loop {
let old_state = state.clone();
match parser.parse(arena, state, min_indent) {
Ok((_, next_output, next_state)) => {
state = next_state;
buf.push(next_output);
}
Err((fail_progress, fail)) => {
match fail_progress {
MadeProgress => {
// made progress on an element and then failed; that's an error
return Err((MadeProgress, fail));
}
NoProgress => {
// the next element failed with no progress
// report whether we made progress before
let progress = Progress::from_lengths(
start_bytes_len,
old_state.bytes().len(),
);
return Ok((progress, buf, old_state));
}
}
}
}
}
}
Err((fail_progress, fail)) => {
match fail_progress {
MadeProgress => {
// made progress on an element and then failed; that's an error
Err((MadeProgress, fail))
}
NoProgress => {
// the first element failed (with no progress), but that's OK
// because we only need to parse 0 elements
Ok((NoProgress, Vec::new_in(arena), original_state))
}
}
}
}
}
}
/// Creates a parser that matches one or more times.
/// Will fail if the given parser fails to match or matches partially.
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, one_or_more};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// # fn foo<'a>(arena: &'a Bump) {
/// let parser = one_or_more(
/// word("hello, ", Problem::NotFound),
/// Problem::NotFound
/// );
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, bumpalo::vec![in &arena; (),()]);
/// assert_eq!(state.pos(), Position::new(14));
///
/// // Error case
/// let (progress, err) = parser.parse(&arena, State::new("bye, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::NotFound(Position::zero()));
/// # }
/// # foo(&arena);
/// ```
pub fn one_or_more<'a, Output, E: 'a>(
parser: impl Parser<'a, Output, E>,
to_error: impl Fn(Position) -> E,
) -> impl Parser<'a, bumpalo::collections::Vec<'a, Output>, E> {
move |arena, state: State<'a>, min_indent: u32| match parser.parse(
arena,
state.clone(),
min_indent,
) {
Ok((_, first_output, next_state)) => {
let mut state = next_state;
let mut buf = Vec::with_capacity_in(1, arena);
buf.push(first_output);
loop {
let old_state = state.clone();
match parser.parse(arena, state, min_indent) {
Ok((_, next_output, next_state)) => {
state = next_state;
buf.push(next_output);
}
Err((NoProgress, _)) => {
return Ok((MadeProgress, buf, old_state));
}
Err((MadeProgress, fail)) => {
return Err((MadeProgress, fail));
}
}
}
}
Err((progress, _)) => Err((progress, to_error(state.pos()))),
}
}
/// Creates a parser that debug prints the result of parsing.
/// It doesn't change the given parser at all,
/// useful for inspecting a parser during development.
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word};
/// # use roc_region::all::Position;
/// # use roc_parse::debug;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// # fn foo<'a>(arena: &'a Bump) {
/// let parser = debug!(
/// word("hello", Problem::NotFound)
/// );
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos().offset, 5);
/// # }
/// # foo(&arena);
/// ```
#[macro_export]
macro_rules! debug {
($parser:expr) => {
move |arena, state: $crate::state::State<'a>, min_indent: u32| {
dbg!($parser.parse(arena, state, min_indent))
}
};
}
/// Matches either of the two given parsers.
/// If the first parser succeeds, its result is used,
/// otherwise, the second parser's result is used.
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, either, Either};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// # fn foo<'a>(arena: &'a Bump) {
/// let parser = either(
/// word("hello", Problem::NotFound),
/// word("bye", Problem::NotFound)
/// );
///
/// // Success cases
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, Either::First(()));
/// assert_eq!(state.pos().offset, 5);
///
/// let (progress, output, state) = parser.parse(&arena, State::new("bye, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, Either::Second(()));
/// assert_eq!(state.pos().offset, 3);
///
/// // Error case
/// let (progress, err) = parser.parse(&arena, State::new("later, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::NotFound(Position::zero()));
/// # }
/// # foo(&arena);
/// ```
pub fn either<'a, OutputLeft, OutputRight, E: 'a>(
p1: impl Parser<'a, OutputLeft, E>,
p2: impl Parser<'a, OutputRight, E>,
) -> impl Parser<'a, Either<OutputLeft, OutputRight>, E> {
move |arena: &'a bumpalo::Bump, state: crate::state::State<'a>, min_indent: u32| {
let original_state = state.clone();
match p1.parse(arena, state, min_indent) {
Ok((progress, output, state)) => {
Ok((progress, crate::parser::Either::First(output), state))
}
Err((NoProgress, _)) => match p2.parse(arena, original_state.clone(), min_indent) {
Ok((progress, output, state)) => {
Ok((progress, crate::parser::Either::Second(output), state))
}
Err((progress, fail)) => Err((progress, fail)),
},
Err((MadeProgress, fail)) => Err((MadeProgress, fail)),
}
}
}
/// Given three parsers, parse them all but ignore the output of the first and last one.
/// Useful for parsing things between two braces (e.g. parentheses).
///
/// If any of the three parsers error, this will error.
///
/// # Example
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, byte, between};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// # fn foo<'a>(arena: &'a Bump) {
/// let parser = between(
/// byte(b'(', Problem::NotFound),
/// word("hello", Problem::NotFound),
/// byte(b')', Problem::NotFound)
/// );
/// let (progress, output, state) = parser.parse(&arena, State::new("(hello), world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos().offset, 7);
/// # }
/// # foo(&arena);
/// ```
pub fn between<'a, Before, Inner, After, Err: 'a>(
opening_brace: impl Parser<'a, Before, Err>,
inner: impl Parser<'a, Inner, Err>,
closing_brace: impl Parser<'a, After, Err>,
) -> impl Parser<'a, Inner, Err> {
skip_first(opening_brace, skip_second(inner, closing_brace))
}
/// Maps/transforms the `Ok` result of parsing using the given function.
/// Similar to [`map`], but the transform function also takes a bump allocator.
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, map_with_arena};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = map_with_arena(
/// word("hello", Problem::NotFound),
/// |_arena, _output| "new output!"
/// );
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::MadeProgress);
/// assert_eq!(output, "new output!");
/// assert_eq!(state.pos(), Position::new(5));
///
/// // Error Case
/// let (progress, err) = parser.parse(&arena, State::new("bye, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::NotFound(Position::zero()));
/// ```
#[inline(always)]
pub fn map_with_arena<'a, P, F, Before, After, E>(
parser: P,
transform: F,
) -> impl Parser<'a, After, E>
where
P: Parser<'a, Before, E>,
F: Fn(&'a Bump, Before) -> After,
E: 'a,
{
move |arena, state, min_indent| {
parser
.parse(arena, state, min_indent)
.map(|(progress, output, next_state)| (progress, transform(arena, output), next_state))
}
}
/// Creates a new parser that does not progress but still forwards the output of
/// the given parser if it succeeds.
///
/// # Example
///
/// ```
/// # #![forbid(unused_imports)]
/// # use roc_parse::state::State;
/// # use crate::roc_parse::parser::{Parser, Progress, word, backtrackable};
/// # use roc_region::all::Position;
/// # use bumpalo::Bump;
/// # #[derive(Debug, PartialEq)]
/// # enum Problem {
/// # NotFound(Position),
/// # }
/// # let arena = Bump::new();
/// let parser = backtrackable(
/// word("hello", Problem::NotFound),
/// );
///
/// // Success case
/// let (progress, output, state) = parser.parse(&arena, State::new("hello, world".as_bytes()), 0).unwrap();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(output, ());
/// assert_eq!(state.pos().offset, 5);
///
/// // Error Case
/// let (progress, err) = parser.parse(&arena, State::new("bye, world".as_bytes()), 0).unwrap_err();
/// assert_eq!(progress, Progress::NoProgress);
/// assert_eq!(err, Problem::NotFound(Position::zero()));
/// ```
pub fn backtrackable<'a, P, Val, Error>(parser: P) -> impl Parser<'a, Val, Error>
where
P: Parser<'a, Val, Error>,
Error: 'a,
{
move |arena: &'a Bump, state: State<'a>, min_indent: u32| match parser
.parse(arena, state, min_indent)
{
Ok((_, a, s1)) => Ok((NoProgress, a, s1)),
Err((_, f)) => Err((NoProgress, f)),
}
}
Reference in a new issue View git blame Copy permalink