real::dfa Class Reference

A maximal-munch DFA over an ordered set of patterns. More...

#include <dfa.hpp>

Collaboration diagram for real::dfa:

Public Member Functions
	dfa (std::span< const detail::program_view > programs)
	Builds the DFA from compiled programs (the embedder path).
	dfa (std::span< const regex > patterns)
	Builds the DFA from regexes (a convenience over regex::raw_program).
std::optional< dfa_match >	match (std::string_view rest) const noexcept
	Matches the longest pattern anchored at the start of rest.
std::size_t	state_count () const noexcept
	The number of states in the minimized automaton (includes the dead state).
std::size_t	rule_count () const noexcept
	The number of patterns the DFA was built from.
std::size_t	class_count () const noexcept
	The number of byte-equivalence classes (the reduced alphabet width).

Static Private Member Functions
static std::vector< detail::program_view >	views_of (std::span< const regex > patterns)
	Materializes program views from patterns (helper for the regex ctor).

Private Attributes
detail::dfa_tables	tables_
	The immutable baked tables.

Detailed Description

A maximal-munch DFA over an ordered set of patterns.

Built once (heap-allocated tables), then immutable and cheap to copy-share. match returns the longest match at the cursor, breaking ties toward the earliest pattern — the lexer's maximal munch, in one pass over the input.

Definition at line 454 of file dfa.hpp.

Constructor & Destructor Documentation

dfa() [1/2]

real::dfa::dfa ( std::span< const detail::program_view >  programs )

inlineexplicit

Builds the DFA from compiled programs (the embedder path).

Parameters

[in]

programs

The patterns' programs, in priority order (see regex::raw_program).

Exceptions

real::dfa_error

if any program holds a non-head zero-width assertion.

Definition at line 463 of file dfa.hpp.

dfa() [2/2]

real::dfa::dfa ( std::span< const regex >  patterns )

inlineexplicit

Builds the DFA from regexes (a convenience over regex::raw_program).

Parameters

[in]

patterns

The patterns, in priority order; they must outlive this call.

Exceptions

real::dfa_error

if any pattern holds a non-head zero-width assertion.

Definition at line 472 of file dfa.hpp.

Member Function Documentation

class_count()

std::size_t real::dfa::class_count ( ) const

inlinenoexcept

The number of byte-equivalence classes (the reduced alphabet width).

Definition at line 519 of file dfa.hpp.

match()

std::optional< dfa_match > real::dfa::match ( std::string_view  rest ) const

inlinenoexcept

Matches the longest pattern anchored at the start of rest.

Maximal munch: the longest match wins; on equal length the earliest pattern (lowest index passed to the constructor) wins; an empty match never wins.

Parameters

[in]

rest

The text to match at its start.

Returns

The winning rule index and byte length, or std::nullopt if nothing non-empty matches.

Definition at line 486 of file dfa.hpp.

rule_count()

std::size_t real::dfa::rule_count ( ) const

inlinenoexcept

The number of patterns the DFA was built from.

Definition at line 513 of file dfa.hpp.

state_count()

std::size_t real::dfa::state_count ( ) const

inlinenoexcept

The number of states in the minimized automaton (includes the dead state).

Definition at line 507 of file dfa.hpp.

views_of()

static std::vector< detail::program_view > real::dfa::views_of ( std::span< const regex >  patterns )

inlinestaticprivate

Materializes program views from patterns (helper for the regex ctor).

Definition at line 527 of file dfa.hpp.

Member Data Documentation

tables_

detail::dfa_tables real::dfa::tables_

private

The immutable baked tables.

Definition at line 537 of file dfa.hpp.

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The documentation for this class was generated from the following file:

• include/real/dfa.hpp