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use super::{
comment,
errors::{ErrorKind, ParserError},
slice::Slice,
};
use crate::ast;
pub type Result<T> = std::result::Result<T, ParserError>;
pub struct Parser<S> {
pub(super) source: S,
pub(super) ptr: usize,
pub(super) length: usize,
}
impl<'s, S> Parser<S>
where
S: Slice<'s>,
{
pub fn new(source: S) -> Self {
let length = source.as_ref().as_bytes().len();
Self {
source,
ptr: 0,
length,
}
}
pub fn parse(
mut self,
) -> std::result::Result<ast::Resource<S>, (ast::Resource<S>, Vec<ParserError>)> {
let mut errors = vec![];
let mut body = vec![];
self.skip_blank_block();
let mut last_comment = None;
let mut last_blank_count = 0;
while self.ptr < self.length {
let entry_start = self.ptr;
let mut entry = self.get_entry(entry_start);
if let Some(comment) = last_comment.take() {
match entry {
Ok(ast::Entry::Message(ref mut msg)) if last_blank_count < 2 => {
msg.comment = Some(comment);
}
Ok(ast::Entry::Term(ref mut term)) if last_blank_count < 2 => {
term.comment = Some(comment);
}
_ => {
body.push(ast::Entry::Comment(comment));
}
}
}
match entry {
Ok(ast::Entry::Comment(comment)) => {
last_comment = Some(comment);
}
Ok(entry) => {
body.push(entry);
}
Err(mut err) => {
self.skip_to_next_entry_start();
err.slice = Some(entry_start..self.ptr);
errors.push(err);
let content = self.source.slice(entry_start..self.ptr);
body.push(ast::Entry::Junk { content });
}
}
last_blank_count = self.skip_blank_block();
}
if let Some(last_comment) = last_comment.take() {
body.push(ast::Entry::Comment(last_comment));
}
if errors.is_empty() {
Ok(ast::Resource { body })
} else {
Err((ast::Resource { body }, errors))
}
}
fn get_entry(&mut self, entry_start: usize) -> Result<ast::Entry<S>> {
let entry = match get_current_byte!(self) {
Some(b'#') => {
let (comment, level) = self.get_comment()?;
match level {
comment::Level::Regular => ast::Entry::Comment(comment),
comment::Level::Group => ast::Entry::GroupComment(comment),
comment::Level::Resource => ast::Entry::ResourceComment(comment),
comment::Level::None => unreachable!(),
}
}
Some(b'-') => ast::Entry::Term(self.get_term(entry_start)?),
_ => ast::Entry::Message(self.get_message(entry_start)?),
};
Ok(entry)
}
pub fn get_message(&mut self, entry_start: usize) -> Result<ast::Message<S>> {
let id = self.get_identifier()?;
self.skip_blank_inline();
self.expect_byte(b'=')?;
let pattern = self.get_pattern()?;
self.skip_blank_block();
let attributes = self.get_attributes();
if pattern.is_none() && attributes.is_empty() {
let entry_id = id.name.as_ref().to_owned();
return error!(
ErrorKind::ExpectedMessageField { entry_id },
entry_start, self.ptr
);
}
Ok(ast::Message {
id,
value: pattern,
attributes,
comment: None,
})
}
pub fn get_term(&mut self, entry_start: usize) -> Result<ast::Term<S>> {
self.expect_byte(b'-')?;
let id = self.get_identifier()?;
self.skip_blank_inline();
self.expect_byte(b'=')?;
self.skip_blank_inline();
let value = self.get_pattern()?;
self.skip_blank_block();
let attributes = self.get_attributes();
if let Some(value) = value {
Ok(ast::Term {
id,
value,
attributes,
comment: None,
})
} else {
error!(
ErrorKind::ExpectedTermField {
entry_id: id.name.as_ref().to_owned()
},
entry_start, self.ptr
)
}
}
fn get_attributes(&mut self) -> Vec<ast::Attribute<S>> {
let mut attributes = vec![];
loop {
let line_start = self.ptr;
self.skip_blank_inline();
if !self.take_byte_if(b'.') {
self.ptr = line_start;
break;
}
if let Ok(attr) = self.get_attribute() {
attributes.push(attr);
} else {
self.ptr = line_start;
break;
}
}
attributes
}
fn get_attribute(&mut self) -> Result<ast::Attribute<S>> {
let id = self.get_identifier()?;
self.skip_blank_inline();
self.expect_byte(b'=')?;
let pattern = self.get_pattern()?;
match pattern {
Some(pattern) => Ok(ast::Attribute { id, value: pattern }),
None => error!(ErrorKind::MissingValue, self.ptr),
}
}
pub(super) fn get_identifier_unchecked(&mut self) -> ast::Identifier<S> {
let mut ptr = self.ptr;
while matches!(get_byte!(self, ptr), Some(b) if b.is_ascii_alphanumeric() || *b == b'-' || *b == b'_')
{
ptr += 1;
}
let name = self.source.slice(self.ptr - 1..ptr);
self.ptr = ptr;
ast::Identifier { name }
}
pub(super) fn get_identifier(&mut self) -> Result<ast::Identifier<S>> {
if !self.is_identifier_start() {
return error!(
ErrorKind::ExpectedCharRange {
range: "a-zA-Z".to_string()
},
self.ptr
);
}
self.ptr += 1;
Ok(self.get_identifier_unchecked())
}
pub(super) fn get_attribute_accessor(&mut self) -> Result<Option<ast::Identifier<S>>> {
if self.take_byte_if(b'.') {
let ident = self.get_identifier()?;
Ok(Some(ident))
} else {
Ok(None)
}
}
fn get_variant_key(&mut self) -> Result<ast::VariantKey<S>> {
self.skip_blank();
let key = if self.is_number_start() {
ast::VariantKey::NumberLiteral {
value: self.get_number_literal()?,
}
} else {
ast::VariantKey::Identifier {
name: self.get_identifier()?.name,
}
};
self.skip_blank();
self.expect_byte(b']')?;
Ok(key)
}
pub(super) fn get_variants(&mut self) -> Result<Vec<ast::Variant<S>>> {
let mut variants = Vec::with_capacity(2);
let mut has_default = false;
loop {
let default = self.take_byte_if(b'*');
if default {
if has_default {
return error!(ErrorKind::MultipleDefaultVariants, self.ptr);
} else {
has_default = true;
}
}
if !self.take_byte_if(b'[') {
break;
}
let key = self.get_variant_key()?;
let value = self.get_pattern()?;
if let Some(value) = value {
variants.push(ast::Variant {
key,
value,
default,
});
self.skip_blank();
} else {
return error!(ErrorKind::MissingValue, self.ptr);
}
}
if has_default {
Ok(variants)
} else {
error!(ErrorKind::MissingDefaultVariant, self.ptr)
}
}
pub(super) fn get_placeable(&mut self) -> Result<ast::Expression<S>> {
self.skip_blank();
let exp = self.get_expression()?;
self.skip_blank_inline();
self.expect_byte(b'}')?;
let invalid_expression_found = match &exp {
ast::Expression::Inline(ast::InlineExpression::TermReference {
ref attribute, ..
}) => attribute.is_some(),
_ => false,
};
if invalid_expression_found {
return error!(ErrorKind::TermAttributeAsPlaceable, self.ptr);
}
Ok(exp)
}
}