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oxigraph/lib/oxttl/src/lexer.rs

976 lines
36 KiB

use crate::toolkit::{TokenRecognizer, TokenRecognizerError};
use memchr::{memchr, memchr2};
use oxilangtag::LanguageTag;
use oxiri::Iri;
use oxrdf::NamedNode;
use std::borrow::Cow;
use std::cmp::min;
use std::collections::HashMap;
use std::ops::Range;
use std::str;
#[derive(Debug, PartialEq, Eq)]
pub enum N3Token<'a> {
IriRef(String),
PrefixedName {
prefix: &'a str,
local: Cow<'a, str>,
might_be_invalid_iri: bool,
},
Variable(Cow<'a, str>),
BlankNodeLabel(&'a str),
String(String),
Integer(&'a str),
Decimal(&'a str),
Double(&'a str),
LangTag(&'a str),
Punctuation(&'a str),
PlainKeyword(&'a str),
}
#[derive(Eq, PartialEq)]
pub enum N3LexerMode {
NTriples,
Turtle,
N3,
}
#[derive(Default)]
pub struct N3LexerOptions {
pub base_iri: Option<Iri<String>>,
}
pub struct N3Lexer {
mode: N3LexerMode,
unchecked: bool,
}
// TODO: there are a lot of 'None' (missing data) returned even if the stream is ending!!!
// TODO: simplify by not giving is_end and fail with an "unexpected eof" is none is returned when is_end=true?
impl TokenRecognizer for N3Lexer {
type Token<'a> = N3Token<'a>;
type Options = N3LexerOptions;
fn recognize_next_token<'a>(
&mut self,
data: &'a [u8],
is_ending: bool,
options: &N3LexerOptions,
) -> Option<(usize, Result<N3Token<'a>, TokenRecognizerError>)> {
match *data.first()? {
b'<' => match *data.get(1)? {
b'<' => Some((2, Ok(N3Token::Punctuation("<<")))),
b'=' if self.mode == N3LexerMode::N3 => {
if let Some((consumed, result)) = self.recognize_iri(data, options) {
Some(if let Ok(result) = result {
(consumed, Ok(result))
} else {
(2, Ok(N3Token::Punctuation("<=")))
})
} else if is_ending {
Some((2, Ok(N3Token::Punctuation("<="))))
} else {
None
}
}
b'-' if self.mode == N3LexerMode::N3 => {
if let Some((consumed, result)) = self.recognize_iri(data, options) {
Some(if let Ok(result) = result {
(consumed, Ok(result))
} else {
(2, Ok(N3Token::Punctuation("<-")))
})
} else if is_ending {
Some((2, Ok(N3Token::Punctuation("<-"))))
} else {
None
}
}
_ => self.recognize_iri(data, options),
},
b'>' => {
if *data.get(1)? == b'>' {
Some((2, Ok(N3Token::Punctuation(">>"))))
} else {
Some((1, Ok(N3Token::Punctuation(">"))))
}
}
b'_' => match data.get(1)? {
b':' => Self::recognize_blank_node_label(data),
c => Some((
1,
Err((0, format!("Unexpected character '{}'", char::from(*c))).into()),
)),
},
b'"' => {
if self.mode != N3LexerMode::NTriples
&& *data.get(1)? == b'"'
&& *data.get(2)? == b'"'
{
Self::recognize_long_string(data, b'"')
} else {
Self::recognize_string(data, b'"')
}
}
b'\'' if self.mode != N3LexerMode::NTriples => {
if *data.get(1)? == b'\'' && *data.get(2)? == b'\'' {
Self::recognize_long_string(data, b'\'')
} else {
Self::recognize_string(data, b'\'')
}
}
b'@' => self.recognize_lang_tag(data),
b'.' => match data.get(1) {
Some(b'0'..=b'9') => Self::recognize_number(data),
Some(_) => Some((1, Ok(N3Token::Punctuation(".")))),
None => is_ending.then_some((1, Ok(N3Token::Punctuation(".")))),
},
b'^' => {
if *data.get(1)? == b'^' {
Some((2, Ok(N3Token::Punctuation("^^"))))
} else {
Some((1, Ok(N3Token::Punctuation("^"))))
}
}
b'(' => Some((1, Ok(N3Token::Punctuation("(")))),
b')' => Some((1, Ok(N3Token::Punctuation(")")))),
b'[' => Some((1, Ok(N3Token::Punctuation("[")))),
b']' => Some((1, Ok(N3Token::Punctuation("]")))),
b'{' => {
if *data.get(1)? == b'|' {
Some((2, Ok(N3Token::Punctuation("{|"))))
} else {
Some((1, Ok(N3Token::Punctuation("{"))))
}
}
b'}' => Some((1, Ok(N3Token::Punctuation("}")))),
b',' => Some((1, Ok(N3Token::Punctuation(",")))),
b';' => Some((1, Ok(N3Token::Punctuation(";")))),
b'!' => Some((1, Ok(N3Token::Punctuation("!")))),
b'|' => {
if *data.get(1)? == b'}' {
Some((2, Ok(N3Token::Punctuation("|}"))))
} else {
Some((1, Ok(N3Token::Punctuation("|"))))
}
}
b'=' => {
if *data.get(1)? == b'>' {
Some((2, Ok(N3Token::Punctuation("=>"))))
} else {
Some((1, Ok(N3Token::Punctuation("="))))
}
}
b'0'..=b'9' | b'+' | b'-' => Self::recognize_number(data),
b'?' => self.recognize_variable(data, is_ending),
_ => self.recognize_pname_or_keyword(data, is_ending),
}
}
}
impl N3Lexer {
pub fn new(mode: N3LexerMode, unchecked: bool) -> Self {
Self { mode, unchecked }
}
fn recognize_iri(
&self,
data: &[u8],
options: &N3LexerOptions,
) -> Option<(usize, Result<N3Token<'static>, TokenRecognizerError>)> {
// [18] IRIREF ::= '<' ([^#x00-#x20<>"{}|^`\] | UCHAR)* '>' /* #x00=NULL #01-#x1F=control codes #x20=space */
let mut string = Vec::new();
let mut i = 1;
loop {
let end = memchr2(b'>', b'\\', &data[i..])?;
string.extend_from_slice(&data[i..i + end]);
i += end;
match data[i] {
b'>' => {
#[allow(clippy::range_plus_one)]
return Some((i + 1, self.parse_iri(string, 0..i + 1, options)));
}
b'\\' => {
let (additional, c) = Self::recognize_escape(&data[i..], i, false)?;
i += additional + 1;
match c {
Ok(c) => {
let mut buf = [0; 4];
string.extend_from_slice(c.encode_utf8(&mut buf).as_bytes());
}
Err(e) => return Some((i, Err(e))),
}
}
_ => unreachable!(),
}
}
}
fn parse_iri(
&self,
iri: Vec<u8>,
position: Range<usize>,
options: &N3LexerOptions,
) -> Result<N3Token<'static>, TokenRecognizerError> {
let iri = string_from_utf8(iri, position.clone())?;
Ok(N3Token::IriRef(
if let Some(base_iri) = options.base_iri.as_ref() {
if self.unchecked {
base_iri.resolve_unchecked(&iri)
} else {
base_iri.resolve(&iri)
}
.map_err(|e| (position, e.to_string()))?
.into_inner()
} else if self.unchecked {
iri
} else {
Iri::parse(iri)
.map_err(|e| (position, e.to_string()))?
.into_inner()
},
))
}
fn recognize_pname_or_keyword<'a>(
&self,
data: &'a [u8],
is_ending: bool,
) -> Option<(usize, Result<N3Token<'a>, TokenRecognizerError>)> {
// [139s] PNAME_NS ::= PN_PREFIX? ':'
// [140s] PNAME_LN ::= PNAME_NS PN_LOCAL
// [167s] PN_PREFIX ::= PN_CHARS_BASE ((PN_CHARS | '.')* PN_CHARS)?
let mut i = 0;
loop {
if let Some(r) = Self::recognize_unicode_char(&data[i..], i) {
match r {
Ok((c, consumed)) => {
if c == ':' {
i += consumed;
break;
} else if i == 0 {
if !Self::is_possible_pn_chars_base(c) {
return Some((
consumed,
Err((
0..consumed,
format!(
"'{c}' is not allowed at the beginning of a prefix name"
),
)
.into()),
));
}
i += consumed;
} else if Self::is_possible_pn_chars(c) || c == '.' {
i += consumed;
} else {
while data[..i].ends_with(b".") {
i -= 1;
}
return Some((
i,
str_from_utf8(&data[..i], 0..i).map(N3Token::PlainKeyword),
));
}
}
Err(e) => return Some((e.location.end, Err(e))),
}
} else if is_ending {
while data[..i].ends_with(b".") {
i -= 1;
}
return Some(if i == 0 {
(
1,
Err((0..1, format!("Unexpected byte {}", data[0])).into()),
)
} else {
(
i,
str_from_utf8(&data[..i], 0..i).map(N3Token::PlainKeyword),
)
});
} else {
return None;
}
}
let pn_prefix = match str_from_utf8(&data[..i - 1], 0..i - 1) {
Ok(pn_prefix) => pn_prefix,
Err(e) => return Some((i, Err(e))),
};
if pn_prefix.ends_with('.') {
return Some((
i,
Err((
0..i,
format!(
"'{pn_prefix}' is not a valid prefix: prefixes are not allowed to end with '.'"),
)
.into()),
));
}
let (consumed, pn_local_result) =
self.recognize_optional_pn_local(&data[i..], is_ending)?;
Some((
consumed + i,
pn_local_result.map(|(local, might_be_invalid_iri)| N3Token::PrefixedName {
prefix: pn_prefix,
local,
might_be_invalid_iri,
}),
))
}
fn recognize_variable<'a>(
&self,
data: &'a [u8],
is_ending: bool,
) -> Option<(usize, Result<N3Token<'a>, TokenRecognizerError>)> {
// [36] QUICK_VAR_NAME ::= "?" PN_LOCAL
let (consumed, result) = self.recognize_optional_pn_local(&data[1..], is_ending)?;
Some((
consumed + 1,
result.and_then(|(name, _)| {
if name.is_empty() {
Err((0..consumed, "A variable name is not allowed to be empty").into())
} else {
Ok(N3Token::Variable(name))
}
}),
))
}
fn recognize_optional_pn_local<'a>(
&self,
data: &'a [u8],
is_ending: bool,
) -> Option<(usize, Result<(Cow<'a, str>, bool), TokenRecognizerError>)> {
// [168s] PN_LOCAL ::= (PN_CHARS_U | ':' | [0-9] | PLX) ((PN_CHARS | '.' | ':' | PLX)* (PN_CHARS | ':' | PLX))?
let mut i = 0;
let mut buffer = None; // Buffer if there are some escaped characters
let mut position_that_is_already_in_buffer = 0;
let mut might_be_invalid_iri = false;
let mut ends_with_unescaped_dot = 0;
loop {
if let Some(r) = Self::recognize_unicode_char(&data[i..], i) {
match r {
Ok((c, consumed)) => {
if c == '%' {
i += 1;
let a = char::from(*data.get(i)?);
i += 1;
let b = char::from(*data.get(i)?);
if !a.is_ascii_hexdigit() || !b.is_ascii_hexdigit() {
return Some((i + 1, Err((
i - 2..=i, format!("escapes in IRIs should be % followed by two hexadecimal characters, found '%{a}{b}'")
).into())));
}
i += 1;
ends_with_unescaped_dot = 0;
} else if c == '\\' {
i += 1;
let a = char::from(*data.get(i)?);
if self.unchecked
|| matches!(
a,
'_' | '~'
| '.'
| '-'
| '!'
| '$'
| '&'
| '\''
| '('
| ')'
| '*'
| '+'
| ','
| ';'
| '='
)
{
// ok to escape
} else if matches!(a, '/' | '?' | '#' | '@' | '%') {
// ok to escape but requires IRI validation
might_be_invalid_iri = true;
} else {
return Some((i + 1, Err((
i..=i, format!("The character that are allowed to be escaped in IRIs are _~.-!$&'()*+,;=/?#@%, found '{a}'")
).into())));
}
let buffer = buffer.get_or_insert_with(String::new);
// We add the missing bytes
if i - position_that_is_already_in_buffer > 1 {
buffer.push_str(
match str_from_utf8(
&data[position_that_is_already_in_buffer..i - 1],
position_that_is_already_in_buffer..i - 1,
) {
Ok(data) => data,
Err(e) => return Some((i, Err(e))),
},
)
}
buffer.push(a);
i += 1;
position_that_is_already_in_buffer = i;
ends_with_unescaped_dot = 0;
} else if i == 0 {
if !(Self::is_possible_pn_chars_u(c) || c == ':' || c.is_ascii_digit())
{
return Some((0, Ok((Cow::Borrowed(""), false))));
}
if !self.unchecked {
might_be_invalid_iri |=
Self::is_possible_pn_chars_base_but_not_valid_iri(c)
|| c == ':';
}
i += consumed;
} else if Self::is_possible_pn_chars(c) || c == ':' {
if !self.unchecked {
might_be_invalid_iri |=
Self::is_possible_pn_chars_base_but_not_valid_iri(c)
|| c == ':';
}
i += consumed;
ends_with_unescaped_dot = 0;
} else if c == '.' {
i += consumed;
ends_with_unescaped_dot += 1;
} else {
let buffer = if let Some(mut buffer) = buffer {
buffer.push_str(
match str_from_utf8(
&data[position_that_is_already_in_buffer..i],
position_that_is_already_in_buffer..i,
) {
Ok(data) => data,
Err(e) => return Some((i, Err(e))),
},
);
// We do not include the last dots
for _ in 0..ends_with_unescaped_dot {
buffer.pop();
}
i -= ends_with_unescaped_dot;
Cow::Owned(buffer)
} else {
let mut data = match str_from_utf8(&data[..i], 0..i) {
Ok(data) => data,
Err(e) => return Some((i, Err(e))),
};
// We do not include the last dots
data = &data[..data.len() - ends_with_unescaped_dot];
i -= ends_with_unescaped_dot;
Cow::Borrowed(data)
};
return Some((i, Ok((buffer, might_be_invalid_iri))));
}
}
Err(e) => return Some((e.location.end, Err(e))),
}
} else if is_ending {
let buffer = if let Some(mut buffer) = buffer {
// We do not include the last dot
while buffer.ends_with('.') {
buffer.pop();
i -= 1;
}
Cow::Owned(buffer)
} else {
let mut data = match str_from_utf8(&data[..i], 0..i) {
Ok(data) => data,
Err(e) => return Some((i, Err(e))),
};
// We do not include the last dot
while let Some(d) = data.strip_suffix('.') {
data = d;
i -= 1;
}
Cow::Borrowed(data)
};
return Some((i, Ok((buffer, might_be_invalid_iri))));
} else {
return None;
}
}
}
fn recognize_blank_node_label(
data: &[u8],
) -> Option<(usize, Result<N3Token<'_>, TokenRecognizerError>)> {
// [141s] BLANK_NODE_LABEL ::= '_:' (PN_CHARS_U | [0-9]) ((PN_CHARS | '.')* PN_CHARS)?
let mut i = 2;
loop {
match Self::recognize_unicode_char(&data[i..], i)? {
Ok((c, consumed)) => {
if (i == 2 && (Self::is_possible_pn_chars_u(c) || c.is_ascii_digit()))
|| (i > 2 && Self::is_possible_pn_chars(c))
{
// Ok
} else if i > 2 && c == '.' {
if data[i - 1] == b'.' {
i -= 1;
return Some((
i,
str_from_utf8(&data[2..i], 2..i).map(N3Token::BlankNodeLabel),
));
}
} else if i == 0 {
return Some((
i,
Err((0..i, "A blank node ID should not be empty").into()),
));
} else if data[i - 1] == b'.' {
i -= 1;
return Some((
i,
str_from_utf8(&data[2..i], 2..i).map(N3Token::BlankNodeLabel),
));
} else {
return Some((
i,
str_from_utf8(&data[2..i], 2..i).map(N3Token::BlankNodeLabel),
));
}
i += consumed;
}
Err(e) => return Some((e.location.end, Err(e))),
}
}
}
fn recognize_lang_tag<'a>(
&self,
data: &'a [u8],
) -> Option<(usize, Result<N3Token<'a>, TokenRecognizerError>)> {
// [144s] LANGTAG ::= '@' [a-zA-Z]+ ('-' [a-zA-Z0-9]+)*
let mut is_last_block_empty = true;
for (i, c) in data[1..].iter().enumerate() {
if c.is_ascii_alphabetic() {
is_last_block_empty = false;
} else if i == 0 {
return Some((
1,
Err((1..2, "A language code should always start with a letter").into()),
));
} else if is_last_block_empty {
return Some((i, self.parse_lang_tag(&data[1..i], 1..i - 1)));
} else if *c == b'-' {
is_last_block_empty = true;
} else {
return Some((i + 1, self.parse_lang_tag(&data[1..=i], 1..i)));
}
}
None
}
fn parse_lang_tag<'a>(
&self,
lang_tag: &'a [u8],
position: Range<usize>,
) -> Result<N3Token<'a>, TokenRecognizerError> {
let lang_tag = str_from_utf8(lang_tag, position.clone())?;
Ok(N3Token::LangTag(if self.unchecked {
lang_tag
} else {
LanguageTag::parse(lang_tag)
.map_err(|e| (position.clone(), e.to_string()))?
.into_inner()
}))
}
fn recognize_string(
data: &[u8],
delimiter: u8,
) -> Option<(usize, Result<N3Token<'static>, TokenRecognizerError>)> {
// [22] STRING_LITERAL_QUOTE ::= '"' ([^#x22#x5C#xA#xD] | ECHAR | UCHAR)* '"' /* #x22=" #x5C=\ #xA=new line #xD=carriage return */
// [23] STRING_LITERAL_SINGLE_QUOTE ::= "'" ([^#x27#x5C#xA#xD] | ECHAR | UCHAR)* "'" /* #x27=' #x5C=\ #xA=new line #xD=carriage return */
let mut string = String::new();
let mut i = 1;
loop {
let end = memchr2(delimiter, b'\\', &data[i..])?;
match str_from_utf8(&data[i..i + end], i..i + end) {
Ok(s) => string.push_str(s),
Err(e) => return Some((end, Err(e))),
};
i += end;
match data[i] {
c if c == delimiter => {
return Some((i + 1, Ok(N3Token::String(string))));
}
b'\\' => {
let (additional, c) = Self::recognize_escape(&data[i..], i, true)?;
i += additional + 1;
match c {
Ok(c) => {
string.push(c);
}
Err(e) => {
// We read until the end of string char
let end = memchr(delimiter, &data[i..])?;
return Some((i + end + 1, Err(e)));
}
}
}
_ => unreachable!(),
}
}
}
fn recognize_long_string(
data: &[u8],
delimiter: u8,
) -> Option<(usize, Result<N3Token<'static>, TokenRecognizerError>)> {
// [24] STRING_LITERAL_LONG_SINGLE_QUOTE ::= "'''" (("'" | "''")? ([^'\] | ECHAR | UCHAR))* "'''"
// [25] STRING_LITERAL_LONG_QUOTE ::= '"""' (('"' | '""')? ([^"\] | ECHAR | UCHAR))* '"""'
let mut string = String::new();
let mut i = 3;
loop {
let end = memchr2(delimiter, b'\\', &data[i..])?;
match str_from_utf8(&data[i..i + end], i..i + end) {
Ok(s) => string.push_str(s),
Err(e) => return Some((end, Err(e))),
};
i += end;
match data[i] {
c if c == delimiter => {
if *data.get(i + 1)? == delimiter && *data.get(i + 2)? == delimiter {
return Some((i + 3, Ok(N3Token::String(string))));
}
i += 1;
string.push(char::from(delimiter));
}
b'\\' => {
let (additional, c) = Self::recognize_escape(&data[i..], i, true)?;
i += additional + 1;
match c {
Ok(c) => {
string.push(c);
}
Err(e) => return Some((i, Err(e))),
}
}
_ => unreachable!(),
}
}
}
fn recognize_number(data: &[u8]) -> Option<(usize, Result<N3Token<'_>, TokenRecognizerError>)> {
// [19] INTEGER ::= [+-]? [0-9]+
// [20] DECIMAL ::= [+-]? [0-9]* '.' [0-9]+
// [21] DOUBLE ::= [+-]? ([0-9]+ '.' [0-9]* EXPONENT | '.' [0-9]+ EXPONENT | [0-9]+ EXPONENT)
// [154s] EXPONENT ::= [eE] [+-]? [0-9]+
let mut i = 0;
let c = *data.first()?;
if matches!(c, b'+' | b'-') {
i += 1;
}
// We read the digits before .
let mut count_before: usize = 0;
loop {
let c = *data.get(i)?;
if c.is_ascii_digit() {
i += 1;
count_before += 1;
} else {
break;
}
}
// We read the digits after .
#[allow(clippy::if_then_some_else_none)]
let count_after = if *data.get(i)? == b'.' {
i += 1;
let mut count_after = 0;
loop {
let c = *data.get(i)?;
if c.is_ascii_digit() {
i += 1;
count_after += 1;
} else {
break;
}
}
Some(count_after)
} else {
None
};
// End
let c = *data.get(i)?;
if matches!(c, b'e' | b'E') {
i += 1;
let c = *data.get(i)?;
if matches!(c, b'+' | b'-') {
i += 1;
}
let mut found = false;
loop {
let c = *data.get(i)?;
if c.is_ascii_digit() {
i += 1;
found = true;
} else {
break;
}
}
Some((
i,
if !found {
Err((0..i, "A double exponent cannot be empty").into())
} else if count_before == 0 && count_after.unwrap_or(0) == 0 {
Err((0..i, "A double should not be empty").into())
} else {
str_from_utf8(&data[..i], 0..i).map(N3Token::Double)
},
))
} else if let Some(count_after) = count_after {
if count_after == 0 {
// We do not consume the '.' after all
i -= 1;
Some((
i,
if count_before == 0 {
Err((0..i, "An integer should not be empty").into())
} else {
str_from_utf8(&data[..i], 0..i).map(N3Token::Integer)
},
))
} else {
Some((i, str_from_utf8(&data[..i], 0..i).map(N3Token::Decimal)))
}
} else {
Some((
i,
if count_before == 0 {
Err((0..i, "An integer should not be empty").into())
} else {
str_from_utf8(&data[..i], 0..i).map(N3Token::Integer)
},
))
}
}
fn recognize_escape(
data: &[u8],
position: usize,
with_echar: bool,
) -> Option<(usize, Result<char, TokenRecognizerError>)> {
// [26] UCHAR ::= '\u' HEX HEX HEX HEX | '\U' HEX HEX HEX HEX HEX HEX HEX HEX
// [159s] ECHAR ::= '\' [tbnrf"'\]
match *data.get(1)? {
b'u' => match Self::recognize_hex_char(&data[2..], 4, 'u', position) {
Ok(c) => Some((5, Ok(c?))),
Err(e) => Some((5, Err(e))),
},
b'U' => match Self::recognize_hex_char(&data[2..], 8, 'u', position) {
Ok(c) => Some((9, Ok(c?))),
Err(e) => Some((9, Err(e))),
},
b't' if with_echar => Some((1, Ok('\t'))),
b'b' if with_echar => Some((1, Ok('\x08'))),
b'n' if with_echar => Some((1, Ok('\n'))),
b'r' if with_echar => Some((1, Ok('\r'))),
b'f' if with_echar => Some((1, Ok('\x0C'))),
b'"' if with_echar => Some((1, Ok('"'))),
b'\'' if with_echar => Some((1, Ok('\''))),
b'\\' if with_echar => Some((1, Ok('\\'))),
c => Some((
1,
Err((
position..position + 2,
format!("Unexpected escape character '\\{}'", char::from(c)),
)
.into()),
)), // TODO: read until end of string
}
}
fn recognize_hex_char(
data: &[u8],
len: usize,
escape_char: char,
position: usize,
) -> Result<Option<char>, TokenRecognizerError> {
if data.len() < len {
return Ok(None);
}
let val = str_from_utf8(&data[..len], position..position + len + 2)?;
let codepoint = u32::from_str_radix(val, 16).map_err(|e| {
(
position..position + len + 2,
format!(
"The escape sequence '\\{escape_char}{val}' is not a valid hexadecimal string: {e}"
),
)
})?;
let c = char::from_u32(codepoint).ok_or_else(|| {
(
position..position + len +2,
format!(
"The escape sequence '\\{escape_char}{val}' is encoding {codepoint:X} that is not a valid unicode character",
),
)
})?;
Ok(Some(c))
}
fn recognize_unicode_char(
data: &[u8],
position: usize,
) -> Option<Result<(char, usize), TokenRecognizerError>> {
let mut code_point: u32;
let bytes_needed: usize;
let mut lower_boundary = 0x80;
let mut upper_boundary = 0xBF;
let byte = *data.first()?;
match byte {
0x00..=0x7F => return Some(Ok((char::from(byte), 1))),
0xC2..=0xDF => {
bytes_needed = 1;
code_point = u32::from(byte) & 0x1F;
}
0xE0..=0xEF => {
if byte == 0xE0 {
lower_boundary = 0xA0;
}
if byte == 0xED {
upper_boundary = 0x9F;
}
bytes_needed = 2;
code_point = u32::from(byte) & 0xF;
}
0xF0..=0xF4 => {
if byte == 0xF0 {
lower_boundary = 0x90;
}
if byte == 0xF4 {
upper_boundary = 0x8F;
}
bytes_needed = 3;
code_point = u32::from(byte) & 0x7;
}
_ => {
return Some(Err((
position..=position,
"Invalid UTF-8 character encoding",
)
.into()))
}
}
for i in 1..=bytes_needed {
let byte = *data.get(i)?;
if byte < lower_boundary || upper_boundary < byte {
return Some(Err((
position..=position + i,
"Invalid UTF-8 character encoding",
)
.into()));
}
lower_boundary = 0x80;
upper_boundary = 0xBF;
code_point = (code_point << 6) | (u32::from(byte) & 0x3F);
}
Some(
char::from_u32(code_point)
.map(|c| (c, bytes_needed + 1))
.ok_or_else(|| {
(
position..=position + bytes_needed,
format!("The codepoint {code_point:X} is not a valid unicode character"),
)
.into()
}),
)
}
// [157s] PN_CHARS_BASE ::= [A-Z] | [a-z] | [#x00C0-#x00D6] | [#x00D8-#x00F6] | [#x00F8-#x02FF] | [#x0370-#x037D] | [#x037F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | [#x10000-#xEFFFF]
fn is_possible_pn_chars_base(c: char) -> bool {
matches!(c,
'A'..='Z'
| 'a'..='z'
| '\u{00C0}'..='\u{00D6}'
| '\u{00D8}'..='\u{00F6}'
| '\u{00F8}'..='\u{02FF}'
| '\u{0370}'..='\u{037D}'
| '\u{037F}'..='\u{1FFF}'
| '\u{200C}'..='\u{200D}'
| '\u{2070}'..='\u{218F}'
| '\u{2C00}'..='\u{2FEF}'
| '\u{3001}'..='\u{D7FF}'
| '\u{F900}'..='\u{FDCF}'
| '\u{FDF0}'..='\u{FFFD}'
| '\u{10000}'..='\u{EFFFF}')
}
// [158s] PN_CHARS_U ::= PN_CHARS_BASE | '_' | ':'
pub(super) fn is_possible_pn_chars_u(c: char) -> bool {
Self::is_possible_pn_chars_base(c) || c == '_'
}
// [160s] PN_CHARS ::= PN_CHARS_U | '-' | [0-9] | #x00B7 | [#x0300-#x036F] | [#x203F-#x2040]
pub(crate) fn is_possible_pn_chars(c: char) -> bool {
Self::is_possible_pn_chars_u(c)
|| matches!(c,
'-' | '0'..='9' | '\u{00B7}' | '\u{0300}'..='\u{036F}' | '\u{203F}'..='\u{2040}')
}
fn is_possible_pn_chars_base_but_not_valid_iri(c: char) -> bool {
matches!(c, '\u{FFF0}'..='\u{FFFD}')
|| u32::from(c) % u32::from('\u{FFFE}') == 0
|| u32::from(c) % u32::from('\u{FFFF}') == 0
}
}
pub fn resolve_local_name(
prefix: &str,
local: &str,
might_be_invalid_iri: bool,
prefixes: &HashMap<String, Iri<String>>,
) -> Result<NamedNode, String> {
if let Some(start) = prefixes.get(prefix) {
let iri = format!("{start}{local}");
if might_be_invalid_iri || start.path().is_empty() {
// We validate again. We always validate if the local part might be the IRI authority.
if let Err(e) = Iri::parse(iri.as_str()) {
return Err(format!(
"The prefixed name {prefix}:{local} builds IRI {iri} that is invalid: {e}"
));
}
}
Ok(NamedNode::new_unchecked(iri))
} else {
Err(format!("The prefix {prefix}: has not been declared"))
}
}
fn str_from_utf8(data: &[u8], range: Range<usize>) -> Result<&str, TokenRecognizerError> {
str::from_utf8(data).map_err(|e| {
(
range.start + e.valid_up_to()..min(range.end, range.start + e.valid_up_to() + 4),
format!("Invalid UTF-8: {e}"),
)
.into()
})
}
fn string_from_utf8(data: Vec<u8>, range: Range<usize>) -> Result<String, TokenRecognizerError> {
String::from_utf8(data).map_err(|e| {
(
range.start + e.utf8_error().valid_up_to()
..min(range.end, range.start + e.utf8_error().valid_up_to() + 4),
format!("Invalid UTF-8: {e}"),
)
.into()
})
}