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Quelle translate.rs
Sprache: unbekannt
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/*!
Defines a translator that converts an `Ast` to an `Hir`.
*/
use core::cell::{Cell, RefCell};
use alloc::{boxed::Box, string::ToString, vec, vec::Vec};
use crate::{
ast::{self, Ast, Span, Visitor},
either::Either,
hir::{self, Error, ErrorKind, Hir, HirKind},
unicode::{self, ClassQuery},
};
type Result<T> = core::result::Result<T, Error>;
/// A builder for constructing an AST->HIR translator.
#[derive(Clone, Debug)]
pub struct TranslatorBuilder {
utf8: bool,
line_terminator: u8,
flags: Flags,
}
impl Default for TranslatorBuilder {
fn default() -> TranslatorBuilder {
TranslatorBuilder::new()
}
}
impl TranslatorBuilder {
/// Create a new translator builder with a default c onfiguration.
pub fn new() -> TranslatorBuilder {
TranslatorBuilder {
utf8: true,
line_terminator: b'\n',
flags: Flags::default(),
}
}
/// Build a translator using the current configuration.
pub fn build(&self) -> Translator {
Translator {
stack: RefCell::new(vec![]),
flags: Cell::new(self.flags),
utf8: self.utf8,
line_terminator: self.line_terminator,
}
}
/// When disabled, translation will permit the construction of a regular
/// expression that may match invalid UTF-8.
///
/// When enabled (the default), the translator is guaranteed to produce an
/// expression that, for non-empty matches, will only ever produce spans
/// that are entirely valid UTF-8 (otherwise, the translator will return an
/// error).
///
/// Perhaps surprisingly, when UTF-8 is enabled, an empty regex or even
/// a negated ASCII word boundary (uttered as `(?-u:\B)` in the concrete
/// syntax) will be allowed even though they can produce matches that split
/// a UTF-8 encoded codepoint. This only applies to zero-width or "empty"
/// matches, and it is expected that the regex engine itself must handle
/// these cases if necessary (perhaps by suppressing any zero-width matches
/// that split a codepoint).
pub fn utf8(&mut self, yes: bool) -> &mut TranslatorBuilder {
self.utf8 = yes;
self
}
/// Sets the line terminator for use with `(?u-s:.)` and `(?-us:.)`.
///
/// Namely, instead of `.` (by default) matching everything except for `\n`,
/// this will cause `.` to match everything except for the byte given.
///
/// If `.` is used in a context where Unicode mode is enabled and this byte
/// isn't ASCII, then an error will be returned. When Unicode mode is
/// disabled, then any byte is permitted, but will return an error if UTF-8
/// mode is enabled and it is a non-ASCII byte.
///
/// In short, any ASCII value for a line terminator is always okay. But a
/// non-ASCII byte might result in an error depending on whether Unicode
/// mode or UTF-8 mode are enabled.
///
/// Note that if `R` mode is enabled then it always takes precedence and
/// the line terminator will be treated as `\r` and `\n` simultaneously.
///
/// Note also that this *doesn't* impact the look-around assertions
/// `(?m:^)` and `(?m:$)`. That's usually controlled by additional
/// configuration in the regex engine itself.
pub fn line_terminator(&mut self, byte: u8) -> &mut TranslatorBuilder {
self.line_terminator = byte;
self
}
/// Enable or disable the case insensitive flag (`i`) by default.
pub fn case_insensitive(&mut self, yes: bool) -> &mut TranslatorBuilder {
self.flags.case_insensitive = if yes { Some(true) } else { None };
self
}
/// Enable or disable the multi-line matching flag (`m`) by default.
pub fn multi_line(&mut self, yes: bool) -> &mut TranslatorBuilder {
self.flags.multi_line = if yes { Some(true) } else { None };
self
}
/// Enable or disable the "dot matches any character" flag (`s`) by
/// default.
pub fn dot_matches_new_line(
&mut self,
yes: bool,
) -> &mut TranslatorBuilder {
self.flags.dot_matches_new_line = if yes { Some(true) } else { None };
self
}
/// Enable or disable the CRLF mode flag (`R`) by default.
pub fn crlf(&mut self, yes: bool) -> &mut TranslatorBuilder {
self.flags.crlf = if yes { Some(true) } else { None };
self
}
/// Enable or disable the "swap greed" flag (`U`) by default.
pub fn swap_greed(&mut self, yes: bool) -> &mut TranslatorBuilder {
self.flags.swap_greed = if yes { Some(true) } else { None };
self
}
/// Enable or disable the Unicode flag (`u`) by default.
pub fn unicode(&mut self, yes: bool) -> &mut TranslatorBuilder {
self.flags.unicode = if yes { None } else { Some(false) };
self
}
}
/// A translator maps abstract syntax to a high level intermediate
/// representation.
///
/// A translator may be benefit from reuse. That is, a translator can translate
/// many abstract syntax trees.
///
/// A `Translator` can be configured in more detail via a
/// [`TranslatorBuilder`].
#[derive(Clone, Debug)]
pub struct Translator {
/// Our call stack, but on the heap.
stack: RefCell<Vec<HirFrame>>,
/// The current flag settings.
flags: Cell<Flags>,
/// Whether we're allowed to produce HIR that can match arbitrary bytes.
utf8: bool,
/// The line terminator to use for `.`.
line_terminator: u8,
}
impl Translator {
/// Create a new translator using the default configuration.
pub fn new() -> Translator {
TranslatorBuilder::new().build()
}
/// Translate the given abstract syntax tree (AST) into a high level
/// intermediate representation (HIR).
///
/// If there was a problem doing the translation, then an HIR-specific
/// error is returned.
///
/// The original pattern string used to produce the `Ast` *must* also be
/// provided. The translator does not use the pattern string during any
/// correct translation, but is used for error reporting.
pub fn translate(&mut self, pattern: &str, ast: &Ast) -> Result<Hir> {
ast::visit(ast, TranslatorI::new(self, pattern))
}
}
/// An HirFrame is a single stack frame, represented explicitly, which is
/// created for each item in the Ast that we traverse.
///
/// Note that technically, this type doesn't represent our entire stack
/// frame. In particular, the Ast visitor represents any state associated with
/// traversing the Ast itself.
#[derive(Clone, Debug)]
enum HirFrame {
/// An arbitrary HIR expression. These get pushed whenever we hit a base
/// case in the Ast. They get popped after an inductive (i.e., recursive)
/// step is complete.
Expr(Hir),
/// A literal that is being constructed, character by character, from the
/// AST. We need this because the AST gives each individual character its
/// own node. So as we see characters, we peek at the top-most HirFrame.
/// If it's a literal, then we add to it. Otherwise, we push a new literal.
/// When it comes time to pop it, we convert it to an Hir via Hir::literal.
Literal(Vec<u8>),
/// A Unicode character class. This frame is mutated as we descend into
/// the Ast of a character class (which is itself its own mini recursive
/// structure).
ClassUnicode(hir::ClassUnicode),
/// A byte-oriented character class. This frame is mutated as we descend
/// into the Ast of a character class (which is itself its own mini
/// recursive structure).
///
/// Byte character classes are created when Unicode mode (`u`) is disabled.
/// If `utf8` is enabled (the default), then a byte character is only
/// permitted to match ASCII text.
ClassBytes(hir::ClassBytes),
/// This is pushed whenever a repetition is observed. After visiting every
/// sub-expression in the repetition, the translator's stack is expected to
/// have this sentinel at the top.
///
/// This sentinel only exists to stop other things (like flattening
/// literals) from reaching across repetition operators.
Repetition,
/// This is pushed on to the stack upon first seeing any kind of capture,
/// indicated by parentheses (including non-capturing groups). It is popped
/// upon leaving a group.
Group {
/// The old active flags when this group was opened.
///
/// If this group sets flags, then the new active flags are set to the
/// result of merging the old flags with the flags introduced by this
/// group. If the group doesn't set any flags, then this is simply
/// equivalent to whatever flags were set when the group was opened.
///
/// When this group is popped, the active flags should be restored to
/// the flags set here.
///
/// The "active" flags correspond to whatever flags are set in the
/// Translator.
old_flags: Flags,
},
/// This is pushed whenever a concatenation is observed. After visiting
/// every sub-expression in the concatenation, the translator's stack is
/// popped until it sees a Concat frame.
Concat,
/// This is pushed whenever an alternation is observed. After visiting
/// every sub-expression in the alternation, the translator's stack is
/// popped until it sees an Alternation frame.
Alternation,
/// This is pushed immediately before each sub-expression in an
/// alternation. This separates the branches of an alternation on the
/// stack and prevents literal flattening from reaching across alternation
/// branches.
///
/// It is popped after each expression in a branch until an 'Alternation'
/// frame is observed when doing a post visit on an alternation.
AlternationBranch,
}
impl HirFrame {
/// Assert that the current stack frame is an Hir expression and return it.
fn unwrap_expr(self) -> Hir {
match self {
HirFrame::Expr(expr) => expr,
HirFrame::Literal(lit) => Hir::literal(lit),
_ => panic!("tried to unwrap expr from HirFrame, got: {:?}", self),
}
}
/// Assert that the current stack frame is a Unicode class expression and
/// return it.
fn unwrap_class_unicode(self) -> hir::ClassUnicode {
match self {
HirFrame::ClassUnicode(cls) => cls,
_ => panic!(
"tried to unwrap Unicode class \
from HirFrame, got: {:?}",
self
),
}
}
/// Assert that the current stack frame is a byte class expression and
/// return it.
fn unwrap_class_bytes(self) -> hir::ClassBytes {
match self {
HirFrame::ClassBytes(cls) => cls,
_ => panic!(
"tried to unwrap byte class \
from HirFrame, got: {:?}",
self
),
}
}
/// Assert that the current stack frame is a repetition sentinel. If it
/// isn't, then panic.
fn unwrap_repetition(self) {
match self {
HirFrame::Repetition => {}
_ => {
panic!(
"tried to unwrap repetition from HirFrame, got: {:?}",
self
)
}
}
}
/// Assert that the current stack frame is a group indicator and return
/// its corresponding flags (the flags that were active at the time the
/// group was entered).
fn unwrap_group(self) -> Flags {
match self {
HirFrame::Group { old_flags } => old_flags,
_ => {
panic!("tried to unwrap group from HirFrame, got: {:?}", self)
}
}
}
/// Assert that the current stack frame is an alternation pipe sentinel. If
/// it isn't, then panic.
fn unwrap_alternation_pipe(self) {
match self {
HirFrame::AlternationBranch => {}
_ => {
panic!(
"tried to unwrap alt pipe from HirFrame, got: {:?}",
self
)
}
}
}
}
impl<'t, 'p> Visitor for TranslatorI<'t, 'p> {
type Output = Hir;
type Err = Error;
fn finish(self) -> Result<Hir> {
// ... otherwise, we should have exactly one HIR on the stack.
assert_eq!(self.trans().stack.borrow().len(), 1);
Ok(self.pop().unwrap().unwrap_expr())
}
fn visit_pre(&mut self, ast: &Ast) -> Result<()> {
match *ast {
Ast::Class(ast::Class::Bracketed(_)) => {
if self.flags().unicode() {
let cls = hir::ClassUnicode::empty();
self.push(HirFrame::ClassUnicode(cls));
} else {
let cls = hir::ClassBytes::empty();
self.push(HirFrame::ClassBytes(cls));
}
}
Ast::Repetition(_) => self.push(HirFrame::Repetition),
Ast::Group(ref x) => {
let old_flags = x
.flags()
.map(|ast| self.set_flags(ast))
.unwrap_or_else(|| self.flags());
self.push(HirFrame::Group { old_flags });
}
Ast::Concat(ref x) if x.asts.is_empty() => {}
Ast::Concat(_) => {
self.push(HirFrame::Concat);
}
Ast::Alternation(ref x) if x.asts.is_empty() => {}
Ast::Alternation(_) => {
self.push(HirFrame::Alternation);
self.push(HirFrame::AlternationBranch);
}
_ => {}
}
Ok(())
}
fn visit_post(&mut self, ast: &Ast) -> Result<()> {
match *ast {
Ast::Empty(_) => {
self.push(HirFrame::Expr(Hir::empty()));
}
Ast::Flags(ref x) => {
self.set_flags(&x.flags);
// Flags in the AST are generally considered directives and
// not actual sub-expressions. However, they can be used in
// the concrete syntax like `((?i))`, and we need some kind of
// indication of an expression there, and Empty is the correct
// choice.
//
// There can also be things like `(?i)+`, but we rule those out
// in the parser. In the future, we might allow them for
// consistency sake.
self.push(HirFrame::Expr(Hir::empty()));
}
Ast::Literal(ref x) => {
match self.ast_literal_to_scalar(x)? {
Either::Right(byte) => self.push_byte(byte),
Either::Left(ch) => {
if !self.flags().unicode() && ch.len_utf8() > 1 {
return Err(self
.error(x.span, ErrorKind::UnicodeNotAllowed));
}
match self.case_fold_char(x.span, ch)? {
None => self.push_char(ch),
Some(expr) => self.push(HirFrame::Expr(expr)),
}
}
}
// self.push(HirFrame::Expr(self.hir_literal(x)?));
}
Ast::Dot(span) => {
self.push(HirFrame::Expr(self.hir_dot(span)?));
}
Ast::Assertion(ref x) => {
self.push(HirFrame::Expr(self.hir_assertion(x)?));
}
Ast::Class(ast::Class::Perl(ref x)) => {
if self.flags().unicode() {
let cls = self.hir_perl_unicode_class(x)?;
let hcls = hir::Class::Unicode(cls);
self.push(HirFrame::Expr(Hir::class(hcls)));
} else {
let cls = self.hir_perl_byte_class(x)?;
let hcls = hir::Class::Bytes(cls);
self.push(HirFrame::Expr(Hir::class(hcls)));
}
}
Ast::Class(ast::Class::Unicode(ref x)) => {
let cls = hir::Class::Unicode(self.hir_unicode_class(x)?);
self.push(HirFrame::Expr(Hir::class(cls)));
}
Ast::Class(ast::Class::Bracketed(ref ast)) => {
if self.flags().unicode() {
let mut cls = self.pop().unwrap().unwrap_class_unicode();
self.unicode_fold_and_negate(
&ast.span,
ast.negated,
&mut cls,
)?;
let expr = Hir::class(hir::Class::Unicode(cls));
self.push(HirFrame::Expr(expr));
} else {
let mut cls = self.pop().unwrap().unwrap_class_bytes();
self.bytes_fold_and_negate(
&ast.span,
ast.negated,
&mut cls,
)?;
let expr = Hir::class(hir::Class::Bytes(cls));
self.push(HirFrame::Expr(expr));
}
}
Ast::Repetition(ref x) => {
let expr = self.pop().unwrap().unwrap_expr();
self.pop().unwrap().unwrap_repetition();
self.push(HirFrame::Expr(self.hir_repetition(x, expr)));
}
Ast::Group(ref x) => {
let expr = self.pop().unwrap().unwrap_expr();
let old_flags = self.pop().unwrap().unwrap_group();
self.trans().flags.set(old_flags);
self.push(HirFrame::Expr(self.hir_capture(x, expr)));
}
Ast::Concat(_) => {
let mut exprs = vec![];
while let Some(expr) = self.pop_concat_expr() {
if !matches!(*expr.kind(), HirKind::Empty) {
exprs.push(expr);
}
}
exprs.reverse();
self.push(HirFrame::Expr(Hir::concat(exprs)));
}
Ast::Alternation(_) => {
let mut exprs = vec![];
while let Some(expr) = self.pop_alt_expr() {
self.pop().unwrap().unwrap_alternation_pipe();
exprs.push(expr);
}
exprs.reverse();
self.push(HirFrame::Expr(Hir::alternation(exprs)));
}
}
Ok(())
}
fn visit_alternation_in(&mut self) -> Result<()> {
self.push(HirFrame::AlternationBranch);
Ok(())
}
fn visit_class_set_item_pre(
&mut self,
ast: &ast::ClassSetItem,
) -> Result<()> {
match *ast {
ast::ClassSetItem::Bracketed(_) => {
if self.flags().unicode() {
let cls = hir::ClassUnicode::empty();
self.push(HirFrame::ClassUnicode(cls));
} else {
let cls = hir::ClassBytes::empty();
self.push(HirFrame::ClassBytes(cls));
}
}
// We needn't handle the Union case here since the visitor will
// do it for us.
_ => {}
}
Ok(())
}
fn visit_class_set_item_post(
&mut self,
ast: &ast::ClassSetItem,
) -> Result<()> {
match *ast {
ast::ClassSetItem::Empty(_) => {}
ast::ClassSetItem::Literal(ref x) => {
if self.flags().unicode() {
let mut cls = self.pop().unwrap().unwrap_class_unicode();
cls.push(hir::ClassUnicodeRange::new(x.c, x.c));
self.push(HirFrame::ClassUnicode(cls));
} else {
let mut cls = self.pop().unwrap().unwrap_class_bytes();
let byte = self.class_literal_byte(x)?;
cls.push(hir::ClassBytesRange::new(byte, byte));
self.push(HirFrame::ClassBytes(cls));
}
}
ast::ClassSetItem::Range(ref x) => {
if self.flags().unicode() {
let mut cls = self.pop().unwrap().unwrap_class_unicode();
cls.push(hir::ClassUnicodeRange::new(x.start.c, x.end.c));
self.push(HirFrame::ClassUnicode(cls));
} else {
let mut cls = self.pop().unwrap().unwrap_class_bytes();
let start = self.class_literal_byte(&x.start)?;
let end = self.class_literal_byte(&x.end)?;
cls.push(hir::ClassBytesRange::new(start, end));
self.push(HirFrame::ClassBytes(cls));
}
}
ast::ClassSetItem::Ascii(ref x) => {
if self.flags().unicode() {
let xcls = self.hir_ascii_unicode_class(x)?;
let mut cls = self.pop().unwrap().unwrap_class_unicode();
cls.union(&xcls);
self.push(HirFrame::ClassUnicode(cls));
} else {
let xcls = self.hir_ascii_byte_class(x)?;
let mut cls = self.pop().unwrap().unwrap_class_bytes();
cls.union(&xcls);
self.push(HirFrame::ClassBytes(cls));
}
}
ast::ClassSetItem::Unicode(ref x) => {
let xcls = self.hir_unicode_class(x)?;
let mut cls = self.pop().unwrap().unwrap_class_unicode();
cls.union(&xcls);
self.push(HirFrame::ClassUnicode(cls));
}
ast::ClassSetItem::Perl(ref x) => {
if self.flags().unicode() {
let xcls = self.hir_perl_unicode_class(x)?;
let mut cls = self.pop().unwrap().unwrap_class_unicode();
cls.union(&xcls);
self.push(HirFrame::ClassUnicode(cls));
} else {
let xcls = self.hir_perl_byte_class(x)?;
let mut cls = self.pop().unwrap().unwrap_class_bytes();
cls.union(&xcls);
self.push(HirFrame::ClassBytes(cls));
}
}
ast::ClassSetItem::Bracketed(ref ast) => {
if self.flags().unicode() {
let mut cls1 = self.pop().unwrap().unwrap_class_unicode();
self.unicode_fold_and_negate(
&ast.span,
ast.negated,
&mut cls1,
)?;
let mut cls2 = self.pop().unwrap().unwrap_class_unicode();
cls2.union(&cls1);
self.push(HirFrame::ClassUnicode(cls2));
} else {
let mut cls1 = self.pop().unwrap().unwrap_class_bytes();
self.bytes_fold_and_negate(
&ast.span,
ast.negated,
&mut cls1,
)?;
let mut cls2 = self.pop().unwrap().unwrap_class_bytes();
cls2.union(&cls1);
self.push(HirFrame::ClassBytes(cls2));
}
}
// This is handled automatically by the visitor.
ast::ClassSetItem::Union(_) => {}
}
Ok(())
}
fn visit_class_set_binary_op_pre(
&mut self,
_op: &ast::ClassSetBinaryOp,
) -> Result<()> {
if self.flags().unicode() {
let cls = hir::ClassUnicode::empty();
self.push(HirFrame::ClassUnicode(cls));
} else {
let cls = hir::ClassBytes::empty();
self.push(HirFrame::ClassBytes(cls));
}
Ok(())
}
fn visit_class_set_binary_op_in(
&mut self,
_op: &ast::ClassSetBinaryOp,
) -> Result<()> {
if self.flags().unicode() {
let cls = hir::ClassUnicode::empty();
self.push(HirFrame::ClassUnicode(cls));
} else {
let cls = hir::ClassBytes::empty();
self.push(HirFrame::ClassBytes(cls));
}
Ok(())
}
fn visit_class_set_binary_op_post(
&mut self,
op: &ast::ClassSetBinaryOp,
) -> Result<()> {
use crate::ast::ClassSetBinaryOpKind::*;
if self.flags().unicode() {
let mut rhs = self.pop().unwrap().unwrap_class_unicode();
let mut lhs = self.pop().unwrap().unwrap_class_unicode();
let mut cls = self.pop().unwrap().unwrap_class_unicode();
if self.flags().case_insensitive() {
rhs.try_case_fold_simple().map_err(|_| {
self.error(
op.rhs.span().clone(),
ErrorKind::UnicodeCaseUnavailable,
)
})?;
lhs.try_case_fold_simple().map_err(|_| {
self.error(
op.lhs.span().clone(),
ErrorKind::UnicodeCaseUnavailable,
)
})?;
}
match op.kind {
Intersection => lhs.intersect(&rhs),
Difference => lhs.difference(&rhs),
SymmetricDifference => lhs.symmetric_difference(&rhs),
}
cls.union(&lhs);
self.push(HirFrame::ClassUnicode(cls));
} else {
let mut rhs = self.pop().unwrap().unwrap_class_bytes();
let mut lhs = self.pop().unwrap().unwrap_class_bytes();
let mut cls = self.pop().unwrap().unwrap_class_bytes();
if self.flags().case_insensitive() {
rhs.case_fold_simple();
lhs.case_fold_simple();
}
match op.kind {
Intersection => lhs.intersect(&rhs),
Difference => lhs.difference(&rhs),
SymmetricDifference => lhs.symmetric_difference(&rhs),
}
cls.union(&lhs);
self.push(HirFrame::ClassBytes(cls));
}
Ok(())
}
}
/// The internal implementation of a translator.
///
/// This type is responsible for carrying around the original pattern string,
/// which is not tied to the internal state of a translator.
///
/// A TranslatorI exists for the time it takes to translate a single Ast.
#[derive(Clone, Debug)]
struct TranslatorI<'t, 'p> {
trans: &'t Translator,
pattern: &'p str,
}
impl<'t, 'p> TranslatorI<'t, 'p> {
/// Build a new internal translator.
fn new(trans: &'t Translator, pattern: &'p str) -> TranslatorI<'t, 'p> {
TranslatorI { trans, pattern }
}
/// Return a reference to the underlying translator.
fn trans(&self) -> &Translator {
&self.trans
}
/// Push the given frame on to the call stack.
fn push(&self, frame: HirFrame) {
self.trans().stack.borrow_mut().push(frame);
}
/// Push the given literal char on to the call stack.
///
/// If the top-most element of the stack is a literal, then the char
/// is appended to the end of that literal. Otherwise, a new literal
/// containing just the given char is pushed to the top of the stack.
fn push_char(&self, ch: char) {
let mut buf = [0; 4];
let bytes = ch.encode_utf8(&mut buf).as_bytes();
let mut stack = self.trans().stack.borrow_mut();
if let Some(HirFrame::Literal(ref mut literal)) = stack.last_mut() {
literal.extend_from_slice(bytes);
} else {
stack.push(HirFrame::Literal(bytes.to_vec()));
}
}
/// Push the given literal byte on to the call stack.
///
/// If the top-most element of the stack is a literal, then the byte
/// is appended to the end of that literal. Otherwise, a new literal
/// containing just the given byte is pushed to the top of the stack.
fn push_byte(&self, byte: u8) {
let mut stack = self.trans().stack.borrow_mut();
if let Some(HirFrame::Literal(ref mut literal)) = stack.last_mut() {
literal.push(byte);
} else {
stack.push(HirFrame::Literal(vec![byte]));
}
}
/// Pop the top of the call stack. If the call stack is empty, return None.
fn pop(&self) -> Option<HirFrame> {
self.trans().stack.borrow_mut().pop()
}
/// Pop an HIR expression from the top of the stack for a concatenation.
///
/// This returns None if the stack is empty or when a concat frame is seen.
/// Otherwise, it panics if it could not find an HIR expression.
fn pop_concat_expr(&self) -> Option<Hir> {
let frame = self.pop()?;
match frame {
HirFrame::Concat => None,
HirFrame::Expr(expr) => Some(expr),
HirFrame::Literal(lit) => Some(Hir::literal(lit)),
HirFrame::ClassUnicode(_) => {
unreachable!("expected expr or concat, got Unicode class")
}
HirFrame::ClassBytes(_) => {
unreachable!("expected expr or concat, got byte class")
}
HirFrame::Repetition => {
unreachable!("expected expr or concat, got repetition")
}
HirFrame::Group { .. } => {
unreachable!("expected expr or concat, got group")
}
HirFrame::Alternation => {
unreachable!("expected expr or concat, got alt marker")
}
HirFrame::AlternationBranch => {
unreachable!("expected expr or concat, got alt branch marker")
}
}
}
/// Pop an HIR expression from the top of the stack for an alternation.
///
/// This returns None if the stack is empty or when an alternation frame is
/// seen. Otherwise, it panics if it could not find an HIR expression.
fn pop_alt_expr(&self) -> Option<Hir> {
let frame = self.pop()?;
match frame {
HirFrame::Alternation => None,
HirFrame::Expr(expr) => Some(expr),
HirFrame::Literal(lit) => Some(Hir::literal(lit)),
HirFrame::ClassUnicode(_) => {
unreachable!("expected expr or alt, got Unicode class")
}
HirFrame::ClassBytes(_) => {
unreachable!("expected expr or alt, got byte class")
}
HirFrame::Repetition => {
unreachable!("expected expr or alt, got repetition")
}
HirFrame::Group { .. } => {
unreachable!("expected expr or alt, got group")
}
HirFrame::Concat => {
unreachable!("expected expr or alt, got concat marker")
}
HirFrame::AlternationBranch => {
unreachable!("expected expr or alt, got alt branch marker")
}
}
}
/// Create a new error with the given span and error type.
fn error(&self, span: Span, kind: ErrorKind) -> Error {
Error { kind, pattern: self.pattern.to_string(), span }
}
/// Return a copy of the active flags.
fn flags(&self) -> Flags {
self.trans().flags.get()
}
/// Set the flags of this translator from the flags set in the given AST.
/// Then, return the old flags.
fn set_flags(&self, ast_flags: &ast::Flags) -> Flags {
let old_flags = self.flags();
let mut new_flags = Flags::from_ast(ast_flags);
new_flags.merge(&old_flags);
self.trans().flags.set(new_flags);
old_flags
}
/// Convert an Ast literal to its scalar representation.
///
/// When Unicode mode is enabled, then this always succeeds and returns a
/// `char` (Unicode scalar value).
///
/// When Unicode mode is disabled, then a `char` will still be returned
/// whenever possible. A byte is returned only when invalid UTF-8 is
/// allowed and when the byte is not ASCII. Otherwise, a non-ASCII byte
/// will result in an error when invalid UTF-8 is not allowed.
fn ast_literal_to_scalar(
&self,
lit: &ast::Literal,
) -> Result<Either<char, u8>> {
if self.flags().unicode() {
return Ok(Either::Left(lit.c));
}
let byte = match lit.byte() {
None => return Ok(Either::Left(lit.c)),
Some(byte) => byte,
};
if byte <= 0x7F {
return Ok(Either::Left(char::try_from(byte).unwrap()));
}
if self.trans().utf8 {
return Err(self.error(lit.span, ErrorKind::InvalidUtf8));
}
Ok(Either::Right(byte))
}
fn case_fold_char(&self, span: Span, c: char) -> Result<Option<Hir>> {
if !self.flags().case_insensitive() {
return Ok(None);
}
if self.flags().unicode() {
// If case folding won't do anything, then don't bother trying.
let map = unicode::SimpleCaseFolder::new()
.map(|f| f.overlaps(c, c))
.map_err(|_| {
self.error(span, ErrorKind::UnicodeCaseUnavailable)
})?;
if !map {
return Ok(None);
}
let mut cls =
hir::ClassUnicode::new(vec![hir::ClassUnicodeRange::new(
c, c,
)]);
cls.try_case_fold_simple().map_err(|_| {
self.error(span, ErrorKind::UnicodeCaseUnavailable)
})?;
Ok(Some(Hir::class(hir::Class::Unicode(cls))))
} else {
if c.len_utf8() > 1 {
return Err(self.error(span, ErrorKind::UnicodeNotAllowed));
}
// If case folding won't do anything, then don't bother trying.
match c {
'A'..='Z' | 'a'..='z' => {}
_ => return Ok(None),
}
let mut cls =
hir::ClassBytes::new(vec![hir::ClassBytesRange::new(
// OK because 'c.len_utf8() == 1' which in turn implies
// that 'c' is ASCII.
u8::try_from(c).unwrap(),
u8::try_from(c).unwrap(),
)]);
cls.case_fold_simple();
Ok(Some(Hir::class(hir::Class::Bytes(cls))))
}
}
fn hir_dot(&self, span: Span) -> Result<Hir> {
let (utf8, lineterm, flags) =
(self.trans().utf8, self.trans().line_terminator, self.flags());
if utf8 && (!flags.unicode() || !lineterm.is_ascii()) {
return Err(self.error(span, ErrorKind::InvalidUtf8));
}
let dot = if flags.dot_matches_new_line() {
if flags.unicode() {
hir::Dot::AnyChar
} else {
hir::Dot::AnyByte
}
} else {
if flags.unicode() {
if flags.crlf() {
hir::Dot::AnyCharExceptCRLF
} else {
if !lineterm.is_ascii() {
return Err(
self.error(span, ErrorKind::InvalidLineTerminator)
);
}
hir::Dot::AnyCharExcept(char::from(lineterm))
}
} else {
if flags.crlf() {
hir::Dot::AnyByteExceptCRLF
} else {
hir::Dot::AnyByteExcept(lineterm)
}
}
};
Ok(Hir::dot(dot))
}
fn hir_assertion(&self, asst: &ast::Assertion) -> Result<Hir> {
let unicode = self.flags().unicode();
let multi_line = self.flags().multi_line();
let crlf = self.flags().crlf();
Ok(match asst.kind {
ast::AssertionKind::StartLine => Hir::look(if multi_line {
if crlf {
hir::Look::StartCRLF
} else {
hir::Look::StartLF
}
} else {
hir::Look::Start
}),
ast::AssertionKind::EndLine => Hir::look(if multi_line {
if crlf {
hir::Look::EndCRLF
} else {
hir::Look::EndLF
}
} else {
hir::Look::End
}),
ast::AssertionKind::StartText => Hir::look(hir::Look::Start),
ast::AssertionKind::EndText => Hir::look(hir::Look::End),
ast::AssertionKind::WordBoundary => Hir::look(if unicode {
hir::Look::WordUnicode
} else {
hir::Look::WordAscii
}),
ast::AssertionKind::NotWordBoundary => Hir::look(if unicode {
hir::Look::WordUnicodeNegate
} else {
hir::Look::WordAsciiNegate
}),
})
}
fn hir_capture(&self, group: &ast::Group, expr: Hir) -> Hir {
let (index, name) = match group.kind {
ast::GroupKind::CaptureIndex(index) => (index, None),
ast::GroupKind::CaptureName { ref name, .. } => {
(name.index, Some(name.name.clone().into_boxed_str()))
}
// The HIR doesn't need to use non-capturing groups, since the way
// in which the data type is defined handles this automatically.
ast::GroupKind::NonCapturing(_) => return expr,
};
Hir::capture(hir::Capture { index, name, sub: Box::new(expr) })
}
fn hir_repetition(&self, rep: &ast::Repetition, expr: Hir) -> Hir {
let (min, max) = match rep.op.kind {
ast::RepetitionKind::ZeroOrOne => (0, Some(1)),
ast::RepetitionKind::ZeroOrMore => (0, None),
ast::RepetitionKind::OneOrMore => (1, None),
ast::RepetitionKind::Range(ast::RepetitionRange::Exactly(m)) => {
(m, Some(m))
}
ast::RepetitionKind::Range(ast::RepetitionRange::AtLeast(m)) => {
(m, None)
}
ast::RepetitionKind::Range(ast::RepetitionRange::Bounded(
m,
n,
)) => (m, Some(n)),
};
let greedy =
if self.flags().swap_greed() { !rep.greedy } else { rep.greedy };
Hir::repetition(hir::Repetition {
min,
max,
greedy,
sub: Box::new(expr),
})
}
fn hir_unicode_class(
&self,
ast_class: &ast::ClassUnicode,
) -> Result<hir::ClassUnicode> {
use crate::ast::ClassUnicodeKind::*;
if !self.flags().unicode() {
return Err(
self.error(ast_class.span, ErrorKind::UnicodeNotAllowed)
);
}
let query = match ast_class.kind {
OneLetter(name) => ClassQuery::OneLetter(name),
Named(ref name) => ClassQuery::Binary(name),
NamedValue { ref name, ref value, .. } => ClassQuery::ByValue {
property_name: name,
property_value: value,
},
};
let mut result = self.convert_unicode_class_error(
&ast_class.span,
unicode::class(query),
);
if let Ok(ref mut class) = result {
self.unicode_fold_and_negate(
&ast_class.span,
ast_class.negated,
class,
)?;
}
result
}
fn hir_ascii_unicode_class(
&self,
ast: &ast::ClassAscii,
) -> Result<hir::ClassUnicode> {
let mut cls = hir::ClassUnicode::new(
ascii_class_as_chars(&ast.kind)
.map(|(s, e)| hir::ClassUnicodeRange::new(s, e)),
);
self.unicode_fold_and_negate(&ast.span, ast.negated, &mut cls)?;
Ok(cls)
}
fn hir_ascii_byte_class(
&self,
ast: &ast::ClassAscii,
) -> Result<hir::ClassBytes> {
let mut cls = hir::ClassBytes::new(
ascii_class(&ast.kind)
.map(|(s, e)| hir::ClassBytesRange::new(s, e)),
);
self.bytes_fold_and_negate(&ast.span, ast.negated, &mut cls)?;
Ok(cls)
}
fn hir_perl_unicode_class(
&self,
ast_class: &ast::ClassPerl,
) -> Result<hir::ClassUnicode> {
use crate::ast::ClassPerlKind::*;
assert!(self.flags().unicode());
let result = match ast_class.kind {
Digit => unicode::perl_digit(),
Space => unicode::perl_space(),
Word => unicode::perl_word(),
};
let mut class =
self.convert_unicode_class_error(&ast_class.span, result)?;
// We needn't apply case folding here because the Perl Unicode classes
// are already closed under Unicode simple case folding.
if ast_class.negated {
class.negate();
}
Ok(class)
}
fn hir_perl_byte_class(
&self,
ast_class: &ast::ClassPerl,
) -> Result<hir::ClassBytes> {
use crate::ast::ClassPerlKind::*;
assert!(!self.flags().unicode());
let mut class = match ast_class.kind {
Digit => hir_ascii_class_bytes(&ast::ClassAsciiKind::Digit),
Space => hir_ascii_class_bytes(&ast::ClassAsciiKind::Space),
Word => hir_ascii_class_bytes(&ast::ClassAsciiKind::Word),
};
// We needn't apply case folding here because the Perl ASCII classes
// are already closed (under ASCII case folding).
if ast_class.negated {
class.negate();
}
// Negating a Perl byte class is likely to cause it to match invalid
// UTF-8. That's only OK if the translator is configured to allow such
// things.
if self.trans().utf8 && !class.is_ascii() {
return Err(self.error(ast_class.span, ErrorKind::InvalidUtf8));
}
Ok(class)
}
/// Converts the given Unicode specific error to an HIR translation error.
///
/// The span given should approximate the position at which an error would
/// occur.
fn convert_unicode_class_error(
&self,
span: &Span,
result: core::result::Result<hir::ClassUnicode, unicode::Error>,
) -> Result<hir::ClassUnicode> {
result.map_err(|err| {
let sp = span.clone();
match err {
unicode::Error::PropertyNotFound => {
self.error(sp, ErrorKind::UnicodePropertyNotFound)
}
unicode::Error::PropertyValueNotFound => {
self.error(sp, ErrorKind::UnicodePropertyValueNotFound)
}
unicode::Error::PerlClassNotFound => {
self.error(sp, ErrorKind::UnicodePerlClassNotFound)
}
}
})
}
fn unicode_fold_and_negate(
&self,
span: &Span,
negated: bool,
class: &mut hir::ClassUnicode,
) -> Result<()> {
// Note that we must apply case folding before negation!
// Consider `(?i)[^x]`. If we applied negation first, then
// the result would be the character class that matched any
// Unicode scalar value.
if self.flags().case_insensitive() {
class.try_case_fold_simple().map_err(|_| {
self.error(span.clone(), ErrorKind::UnicodeCaseUnavailable)
})?;
}
if negated {
class.negate();
}
Ok(())
}
fn bytes_fold_and_negate(
&self,
span: &Span,
negated: bool,
class: &mut hir::ClassBytes,
) -> Result<()> {
// Note that we must apply case folding before negation!
// Consider `(?i)[^x]`. If we applied negation first, then
// the result would be the character class that matched any
// Unicode scalar value.
if self.flags().case_insensitive() {
class.case_fold_simple();
}
if negated {
class.negate();
}
if self.trans().utf8 && !class.is_ascii() {
return Err(self.error(span.clone(), ErrorKind::InvalidUtf8));
}
Ok(())
}
/// Return a scalar byte value suitable for use as a literal in a byte
/// character class.
fn class_literal_byte(&self, ast: &ast::Literal) -> Result<u8> {
match self.ast_literal_to_scalar(ast)? {
Either::Right(byte) => Ok(byte),
Either::Left(ch) => {
let cp = u32::from(ch);
if cp <= 0x7F {
Ok(u8::try_from(cp).unwrap())
} else {
// We can't feasibly support Unicode in
// byte oriented classes. Byte classes don't
// do Unicode case folding.
Err(self.error(ast.span, ErrorKind::UnicodeNotAllowed))
}
}
}
}
}
/// A translator's representation of a regular expression's flags at any given
/// moment in time.
///
/// Each flag can be in one of three states: absent, present but disabled or
/// present but enabled.
#[derive(Clone, Copy, Debug, Default)]
struct Flags {
case_insensitive: Option<bool>,
multi_line: Option<bool>,
dot_matches_new_line: Option<bool>,
swap_greed: Option<bool>,
unicode: Option<bool>,
crlf: Option<bool>,
// Note that `ignore_whitespace` is omitted here because it is handled
// entirely in the parser.
}
impl Flags {
fn from_ast(ast: &ast::Flags) -> Flags {
let mut flags = Flags::default();
let mut enable = true;
for item in &ast.items {
match item.kind {
ast::FlagsItemKind::Negation => {
enable = false;
}
ast::FlagsItemKind::Flag(ast::Flag::CaseInsensitive) => {
flags.case_insensitive = Some(enable);
}
ast::FlagsItemKind::Flag(ast::Flag::MultiLine) => {
flags.multi_line = Some(enable);
}
ast::FlagsItemKind::Flag(ast::Flag::DotMatchesNewLine) => {
flags.dot_matches_new_line = Some(enable);
}
ast::FlagsItemKind::Flag(ast::Flag::SwapGreed) => {
flags.swap_greed = Some(enable);
}
ast::FlagsItemKind::Flag(ast::Flag::Unicode) => {
flags.unicode = Some(enable);
}
ast::FlagsItemKind::Flag(ast::Flag::CRLF) => {
flags.crlf = Some(enable);
}
ast::FlagsItemKind::Flag(ast::Flag::IgnoreWhitespace) => {}
}
}
flags
}
fn merge(&mut self, previous: &Flags) {
if self.case_insensitive.is_none() {
self.case_insensitive = previous.case_insensitive;
}
if self.multi_line.is_none() {
self.multi_line = previous.multi_line;
}
if self.dot_matches_new_line.is_none() {
self.dot_matches_new_line = previous.dot_matches_new_line;
}
if self.swap_greed.is_none() {
self.swap_greed = previous.swap_greed;
}
if self.unicode.is_none() {
self.unicode = previous.unicode;
}
if self.crlf.is_none() {
self.crlf = previous.crlf;
}
}
fn case_insensitive(&self) -> bool {
self.case_insensitive.unwrap_or(false)
}
fn multi_line(&self) -> bool {
self.multi_line.unwrap_or(false)
}
fn dot_matches_new_line(&self) -> bool {
self.dot_matches_new_line.unwrap_or(false)
}
fn swap_greed(&self) -> bool {
self.swap_greed.unwrap_or(false)
}
fn unicode(&self) -> bool {
self.unicode.unwrap_or(true)
}
fn crlf(&self) -> bool {
self.crlf.unwrap_or(false)
}
}
fn hir_ascii_class_bytes(kind: &ast::ClassAsciiKind) -> hir::ClassBytes {
let ranges: Vec<_> = ascii_class(kind)
.map(|(s, e)| hir::ClassBytesRange::new(s, e))
.collect();
hir::ClassBytes::new(ranges)
}
fn ascii_class(kind: &ast::ClassAsciiKind) -> impl Iterator<Item = (u8, u8)> {
use crate::ast::ClassAsciiKind::*;
let slice: &'static [(u8, u8)] = match *kind {
Alnum => &[(b'0', b'9'), (b'A', b'Z'), (b'a', b'z')],
Alpha => &[(b'A', b'Z'), (b'a', b'z')],
Ascii => &[(b'\x00', b'\x7F')],
Blank => &[(b'\t', b'\t'), (b' ', b' ')],
Cntrl => &[(b'\x00', b'\x1F'), (b'\x7F', b'\x7F')],
Digit => &[(b'0', b'9')],
Graph => &[(b'!', b'~')],
Lower => &[(b'a', b'z')],
Print => &[(b' ', b'~')],
Punct => &[(b'!', b'/'), (b':', b'@'), (b'[', b'`'), (b'{', b'~')],
Space => &[
(b'\t', b'\t'),
(b'\n', b'\n'),
(b'\x0B', b'\x0B'),
(b'\x0C', b'\x0C'),
(b'\r', b'\r'),
(b' ', b' '),
],
Upper => &[(b'A', b'Z')],
Word => &[(b'0', b'9'), (b'A', b'Z'), (b'_', b'_'), (b'a', b'z')],
Xdigit => &[(b'0', b'9'), (b'A', b'F'), (b'a', b'f')],
};
slice.iter().copied()
}
fn ascii_class_as_chars(
kind: &ast::ClassAsciiKind,
) -> impl Iterator<Item = (char, char)> {
ascii_class(kind).map(|(s, e)| (char::from(s), char::from(e)))
}
#[cfg(test)]
mod tests {
use crate::{
ast::{self, parse::ParserBuilder, Ast, Position, Span},
hir::{self, Hir, HirKind, Look, Properties},
unicode::{self, ClassQuery},
};
use super::*;
// We create these errors to compare with real hir::Errors in the tests.
// We define equality between TestError and hir::Error to disregard the
// pattern string in hir::Error, which is annoying to provide in tests.
#[derive(Clone, Debug)]
struct TestError {
span: Span,
kind: hir::ErrorKind,
}
impl PartialEq<hir::Error> for TestError {
fn eq(&self, other: &hir::Error) -> bool {
self.span == other.span && self.kind == other.kind
}
}
impl PartialEq<TestError> for hir::Error {
fn eq(&self, other: &TestError) -> bool {
self.span == other.span && self.kind == other.kind
}
}
fn parse(pattern: &str) -> Ast {
ParserBuilder::new().octal(true).build().parse(pattern).unwrap()
}
fn t(pattern: &str) -> Hir {
TranslatorBuilder::new()
.utf8(true)
.build()
.translate(pattern, &parse(pattern))
.unwrap()
}
fn t_err(pattern: &str) -> hir::Error {
TranslatorBuilder::new()
.utf8(true)
.build()
.translate(pattern, &parse(pattern))
.unwrap_err()
}
fn t_bytes(pattern: &str) -> Hir {
TranslatorBuilder::new()
.utf8(false)
.build()
.translate(pattern, &parse(pattern))
.unwrap()
}
fn props(pattern: &str) -> Properties {
t(pattern).properties().clone()
}
fn props_bytes(pattern: &str) -> Properties {
t_bytes(pattern).properties().clone()
}
fn hir_lit(s: &str) -> Hir {
hir_blit(s.as_bytes())
}
fn hir_blit(s: &[u8]) -> Hir {
Hir::literal(s)
}
fn hir_capture(index: u32, expr: Hir) -> Hir {
Hir::capture(hir::Capture { index, name: None, sub: Box::new(expr) })
}
fn hir_capture_name(index: u32, name: &str, expr: Hir) -> Hir {
Hir::capture(hir::Capture {
index,
name: Some(name.into()),
sub: Box::new(expr),
})
}
fn hir_quest(greedy: bool, expr: Hir) -> Hir {
Hir::repetition(hir::Repetition {
min: 0,
max: Some(1),
greedy,
sub: Box::new(expr),
})
}
fn hir_star(greedy: bool, expr: Hir) -> Hir {
Hir::repetition(hir::Repetition {
min: 0,
max: None,
greedy,
sub: Box::new(expr),
})
}
fn hir_plus(greedy: bool, expr: Hir) -> Hir {
Hir::repetition(hir::Repetition {
min: 1,
max: None,
greedy,
sub: Box::new(expr),
})
}
fn hir_range(greedy: bool, min: u32, max: Option<u32>, expr: Hir) -> Hir {
Hir::repetition(hir::Repetition {
min,
max,
greedy,
sub: Box::new(expr),
})
}
fn hir_alt(alts: Vec<Hir>) -> Hir {
Hir::alternation(alts)
}
fn hir_cat(exprs: Vec<Hir>) -> Hir {
Hir::concat(exprs)
}
#[allow(dead_code)]
fn hir_uclass_query(query: ClassQuery<'_>) -> Hir {
Hir::class(hir::Class::Unicode(unicode::class(query).unwrap()))
}
#[allow(dead_code)]
fn hir_uclass_perl_word() -> Hir {
Hir::class(hir::Class::Unicode(unicode::perl_word().unwrap()))
}
fn hir_ascii_uclass(kind: &ast::ClassAsciiKind) -> Hir {
Hir::class(hir::Class::Unicode(hir::ClassUnicode::new(
ascii_class_as_chars(kind)
.map(|(s, e)| hir::ClassUnicodeRange::new(s, e)),
)))
}
fn hir_ascii_bclass(kind: &ast::ClassAsciiKind) -> Hir {
Hir::class(hir::Class::Bytes(hir::ClassBytes::new(
ascii_class(kind).map(|(s, e)| hir::ClassBytesRange::new(s, e)),
)))
}
fn hir_uclass(ranges: &[(char, char)]) -> Hir {
Hir::class(uclass(ranges))
}
fn hir_bclass(ranges: &[(u8, u8)]) -> Hir {
Hir::class(bclass(ranges))
}
fn hir_case_fold(expr: Hir) -> Hir {
match expr.into_kind() {
HirKind::Class(mut cls) => {
cls.case_fold_simple();
Hir::class(cls)
}
_ => panic!("cannot case fold non-class Hir expr"),
}
}
fn hir_negate(expr: Hir) -> Hir {
match expr.into_kind() {
HirKind::Class(mut cls) => {
cls.negate();
Hir::class(cls)
}
_ => panic!("cannot negate non-class Hir expr"),
}
}
fn uclass(ranges: &[(char, char)]) -> hir::Class {
let ranges: Vec<hir::ClassUnicodeRange> = ranges
.iter()
.map(|&(s, e)| hir::ClassUnicodeRange::new(s, e))
.collect();
hir::Class::Unicode(hir::ClassUnicode::new(ranges))
}
fn bclass(ranges: &[(u8, u8)]) -> hir::Class {
let ranges: Vec<hir::ClassBytesRange> = ranges
.iter()
.map(|&(s, e)| hir::ClassBytesRange::new(s, e))
.collect();
hir::Class::Bytes(hir::ClassBytes::new(ranges))
}
#[cfg(feature = "unicode-case")]
fn class_case_fold(mut cls: hir::Class) -> Hir {
cls.case_fold_simple();
Hir::class(cls)
}
fn class_negate(mut cls: hir::Class) -> Hir {
cls.negate();
Hir::class(cls)
}
#[allow(dead_code)]
fn hir_union(expr1: Hir, expr2: Hir) -> Hir {
use crate::hir::Class::{Bytes, Unicode};
match (expr1.into_kind(), expr2.into_kind()) {
(HirKind::Class(Unicode(mut c1)), HirKind::Class(Unicode(c2))) => {
c1.union(&c2);
Hir::class(hir::Class::Unicode(c1))
}
(HirKind::Class(Bytes(mut c1)), HirKind::Class(Bytes(c2))) => {
c1.union(&c2);
Hir::class(hir::Class::Bytes(c1))
}
_ => panic!("cannot union non-class Hir exprs"),
}
}
#[allow(dead_code)]
fn hir_difference(expr1: Hir, expr2: Hir) -> Hir {
use crate::hir::Class::{Bytes, Unicode};
match (expr1.into_kind(), expr2.into_kind()) {
(HirKind::Class(Unicode(mut c1)), HirKind::Class(Unicode(c2))) => {
c1.difference(&c2);
Hir::class(hir::Class::Unicode(c1))
}
(HirKind::Class(Bytes(mut c1)), HirKind::Class(Bytes(c2))) => {
c1.difference(&c2);
Hir::class(hir::Class::Bytes(c1))
}
_ => panic!("cannot difference non-class Hir exprs"),
}
}
fn hir_look(look: hir::Look) -> Hir {
Hir::look(look)
}
#[test]
fn empty() {
assert_eq!(t(""), Hir::empty());
assert_eq!(t("(?i)"), Hir::empty());
assert_eq!(t("()"), hir_capture(1, Hir::empty()));
assert_eq!(t("(?:)"), Hir::empty());
assert_eq!(t("(?P<wat>)"), hir_capture_name(1, "wat", Hir::empty()));
assert_eq!(t("|"), hir_alt(vec![Hir::empty(), Hir::empty()]));
assert_eq!(
t("()|()"),
hir_alt(vec![
hir_capture(1, Hir::empty()),
hir_capture(2, Hir::empty()),
])
);
assert_eq!(
t("(|b)"),
hir_capture(1, hir_alt(vec![Hir::empty(), hir_lit("b"),]))
);
assert_eq!(
t("(a|)"),
hir_capture(1, hir_alt(vec![hir_lit("a"), Hir::empty(),]))
);
assert_eq!(
t("(a||c)"),
hir_capture(
1,
hir_alt(vec![hir_lit("a"), Hir::empty(), hir_lit("c"),])
)
);
assert_eq!(
t("(||)"),
hir_capture(
1,
hir_alt(vec![Hir::empty(), Hir::empty(), Hir::empty(),])
)
);
}
#[test]
fn literal() {
assert_eq!(t("a"), hir_lit("a"));
assert_eq!(t("(?-u)a"), hir_lit("a"));
assert_eq!(t("☃"), hir_lit("☃"));
assert_eq!(t("abcd"), hir_lit("abcd"));
assert_eq!(t_bytes("(?-u)a"), hir_lit("a"));
assert_eq!(t_bytes("(?-u)\x61"), hir_lit("a"));
assert_eq!(t_bytes(r"(?-u)\x61"), hir_lit("a"));
assert_eq!(t_bytes(r"(?-u)\xFF"), hir_blit(b"\xFF"));
assert_eq!(
t_err("(?-u)☃"),
TestError {
kind: hir::ErrorKind::UnicodeNotAllowed,
span: Span::new(
Position::new(5, 1, 6),
Position::new(8, 1, 7)
),
}
);
assert_eq!(
t_err(r"(?-u)\xFF"),
TestError {
kind: hir::ErrorKind::InvalidUtf8,
span: Span::new(
Position::new(5, 1, 6),
Position::new(9, 1, 10)
),
}
);
}
#[test]
fn literal_case_insensitive() {
#[cfg(feature = "unicode-case")]
assert_eq!(t("(?i)a"), hir_uclass(&[('A', 'A'), ('a', 'a'),]));
#[cfg(feature = "unicode-case")]
assert_eq!(t("(?i:a)"), hir_uclass(&[('A', 'A'), ('a', 'a')]));
#[cfg(feature = "unicode-case")]
assert_eq!(
t("a(?i)a(?-i)a"),
hir_cat(vec![
hir_lit("a"),
hir_uclass(&[('A', 'A'), ('a', 'a')]),
hir_lit("a"),
])
);
#[cfg(feature = "unicode-case")]
assert_eq!(
t("(?i)ab@c"),
hir_cat(vec![
hir_uclass(&[('A', 'A'), ('a', 'a')]),
hir_uclass(&[('B', 'B'), ('b', 'b')]),
hir_lit("@"),
hir_uclass(&[('C', 'C'), ('c', 'c')]),
])
);
#[cfg(feature = "unicode-case")]
assert_eq!(
t("(?i)β"),
hir_uclass(&[('Β', 'Β'), ('β', 'β'), ('ϐ', 'ϐ'),])
);
assert_eq!(t("(?i-u)a"), hir_bclass(&[(b'A', b'A'), (b'a', b'a'),]));
#[cfg(feature = "unicode-case")]
assert_eq!(
t("(?-u)a(?i)a(?-i)a"),
hir_cat(vec![
hir_lit("a"),
hir_bclass(&[(b'A', b'A'), (b'a', b'a')]),
hir_lit("a"),
])
);
assert_eq!(
t("(?i-u)ab@c"),
hir_cat(vec![
hir_bclass(&[(b'A', b'A'), (b'a', b'a')]),
hir_bclass(&[(b'B', b'B'), (b'b', b'b')]),
hir_lit("@"),
hir_bclass(&[(b'C', b'C'), (b'c', b'c')]),
])
);
assert_eq!(
t_bytes("(?i-u)a"),
hir_bclass(&[(b'A', b'A'), (b'a', b'a'),])
);
assert_eq!(
t_bytes("(?i-u)\x61"),
hir_bclass(&[(b'A', b'A'), (b'a', b'a'),])
);
assert_eq!(
t_bytes(r"(?i-u)\x61"),
hir_bclass(&[(b'A', b'A'), (b'a', b'a'),])
);
assert_eq!(t_bytes(r"(?i-u)\xFF"), hir_blit(b"\xFF"));
assert_eq!(
t_err("(?i-u)β"),
TestError {
kind: hir::ErrorKind::UnicodeNotAllowed,
span: Span::new(
Position::new(6, 1, 7),
Position::new(8, 1, 8),
),
}
);
}
#[test]
fn dot() {
assert_eq!(
t("."),
hir_uclass(&[('\0', '\t'), ('\x0B', '\u{10FFFF}')])
);
assert_eq!(
t("(?R)."),
hir_uclass(&[
('\0', '\t'),
('\x0B', '\x0C'),
('\x0E', '\u{10FFFF}'),
])
);
assert_eq!(t("(?s)."), hir_uclass(&[('\0', '\u{10FFFF}')]));
assert_eq!(t("(?Rs)."), hir_uclass(&[('\0', '\u{10FFFF}')]));
assert_eq!(
t_bytes("(?-u)."),
hir_bclass(&[(b'\0', b'\t'), (b'\x0B', b'\xFF')])
);
assert_eq!(
t_bytes("(?R-u)."),
hir_bclass(&[
(b'\0', b'\t'),
(b'\x0B', b'\x0C'),
(b'\x0E', b'\xFF'),
])
);
assert_eq!(t_bytes("(?s-u)."), hir_bclass(&[(b'\0', b'\xFF'),]));
assert_eq!(t_bytes("(?Rs-u)."), hir_bclass(&[(b'\0', b'\xFF'),]));
// If invalid UTF-8 isn't allowed, then non-Unicode `.` isn't allowed.
assert_eq!(
t_err("(?-u)."),
TestError {
kind: hir::ErrorKind::InvalidUtf8,
span: Span::new(
Position::new(5, 1, 6),
Position::new(6, 1, 7)
),
}
);
assert_eq!(
t_err("(?R-u)."),
TestError {
kind: hir::ErrorKind::InvalidUtf8,
span: Span::new(
Position::new(6, 1, 7),
Position::new(7, 1, 8)
),
}
);
assert_eq!(
t_err("(?s-u)."),
TestError {
kind: hir::ErrorKind::InvalidUtf8,
span: Span::new(
Position::new(6, 1, 7),
Position::new(7, 1, 8)
),
}
);
assert_eq!(
t_err("(?Rs-u)."),
TestError {
kind: hir::ErrorKind::InvalidUtf8,
span: Span::new(
Position::new(7, 1, 8),
Position::new(8, 1, 9)
),
}
);
}
#[test]
fn assertions() {
assert_eq!(t("^"), hir_look(hir::Look::Start));
assert_eq!(t("$"), hir_look(hir::Look::End));
assert_eq!(t(r"\A"), hir_look(hir::Look::Start));
assert_eq!(t(r"\z"), hir_look(hir::Look::End));
assert_eq!(t("(?m)^"), hir_look(hir::Look::StartLF));
assert_eq!(t("(?m)$"), hir_look(hir::Look::EndLF));
assert_eq!(t(r"(?m)\A"), hir_look(hir::Look::Start));
assert_eq!(t(r"(?m)\z"), hir_look(hir::Look::End));
assert_eq!(t(r"\b"), hir_look(hir::Look::WordUnicode));
assert_eq!(t(r"\B"), hir_look(hir::Look::WordUnicodeNegate));
assert_eq!(t(r"(?-u)\b"), hir_look(hir::Look::WordAscii));
assert_eq!(t(r"(?-u)\B"), hir_look(hir::Look::WordAsciiNegate));
}
#[test]
fn group() {
assert_eq!(t("(a)"), hir_capture(1, hir_lit("a")));
assert_eq!(
t("(a)(b)"),
hir_cat(vec![
hir_capture(1, hir_lit("a")),
hir_capture(2, hir_lit("b")),
])
);
assert_eq!(
t("(a)|(b)"),
hir_alt(vec![
hir_capture(1, hir_lit("a")),
hir_capture(2, hir_lit("b")),
])
);
assert_eq!(t("(?P<foo>)"), hir_capture_name(1, "foo", Hir::empty()));
assert_eq!(t("(?P<foo>a)"), hir_capture_name(1, "foo", hir_lit("a")));
assert_eq!(
t("(?P<foo>a)(?P<bar>b)"),
hir_cat(vec![
hir_capture_name(1, "foo", hir_lit("a")),
hir_capture_name(2, "bar", hir_lit("b")),
])
);
assert_eq!(t("(?:)"), Hir::empty());
assert_eq!(t("(?:a)"), hir_lit("a"));
assert_eq!(
t("(?:a)(b)"),
hir_cat(vec![hir_lit("a"), hir_capture(1, hir_lit("b")),])
);
assert_eq!(
t("(a)(?:b)(c)"),
hir_cat(vec![
hir_capture(1, hir_lit("a")),
hir_lit("b"),
hir_capture(2, hir_lit("c")),
--> --------------------
--> maximum size reached
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[ Dauer der Verarbeitung: 0.90 Sekunden
(vorverarbeitet)
]
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2026-04-02
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