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use crate::{
algo::visit::{visitor_ctx, VisitorCtx},
ast::{self, AstNode},
File,
string_lexing::{self, CharComponentKind},
yellow::{
SyntaxError,
SyntaxErrorKind::*,
},
};
pub(crate) fn validate(file: &File) -> Vec<SyntaxError> {
let mut errors = Vec::new();
for node in file.root.borrowed().descendants() {
let _ = visitor_ctx(&mut errors)
.visit::<ast::Char, _>(validate_char)
.accept(node);
}
errors
}
fn validate_char(node: ast::Char, errors: &mut Vec<SyntaxError>) {
let mut components = string_lexing::parse_char_literal(node.text());
let mut len = 0;
for component in &mut components {
len += 1;
// Validate escapes
let text = &node.text()[component.range];
let range = component.range + node.syntax().range().start();
use self::CharComponentKind::*;
match component.kind {
AsciiEscape => {
if text.len() == 1 {
// Escape sequence consists only of leading `\`
errors.push(SyntaxError::new(EmptyAsciiEscape, range));
} else {
let escape_code = text.chars().skip(1).next().unwrap();
if !is_ascii_escape(escape_code) {
errors.push(SyntaxError::new(InvalidAsciiEscape, range));
}
}
}
AsciiCodeEscape => {
// TODO:
// * First digit is octal
// * Second digit is hex
}
UnicodeEscape => {
// TODO:
// * Only hex digits or underscores allowed
// * Max 6 chars
// * Within allowed range (must be at most 10FFFF)
}
// Code points are always valid
CodePoint => (),
}
}
if !components.has_closing_quote {
errors.push(SyntaxError::new(UnclosedChar, node.syntax().range()));
}
if len == 0 {
errors.push(SyntaxError::new(EmptyChar, node.syntax().range()));
}
if len > 1 {
errors.push(SyntaxError::new(LongChar, node.syntax().range()));
}
}
fn is_ascii_escape(code: char) -> bool {
match code {
'\'' | '"' | 'n' | 'r' | 't' | '0' => true,
_ => false,
}
}
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