InputScanner.cs
84 lines
| 2.6 KiB
| text/x-csharp
|
CSharpLexer
cin
|
r289 | using Implab.Automaton; | ||
| using System; | ||||
| using System.Collections.Generic; | ||||
| using System.Linq; | ||||
| using System.Runtime.CompilerServices; | ||||
| using System.Text; | ||||
| using System.Threading.Tasks; | ||||
| namespace Implab.Formats { | ||||
| public class InputScanner<TTag> { | ||||
| readonly TTag[] m_tags; | ||||
| readonly int m_initialState; | ||||
| readonly int[,] m_dfa; | ||||
| readonly CharMap m_alphabet; | ||||
| readonly bool[] m_final; | ||||
| int m_position; | ||||
| int m_state; | ||||
| public InputScanner(int[,] dfaTable, bool[] finalStates, TTag[] tags, int initialState, CharMap alphabet) { | ||||
| Safe.ArgumentNotNull(dfaTable, nameof(dfaTable)); | ||||
| Safe.ArgumentNotNull(finalStates, nameof(finalStates)); | ||||
| Safe.ArgumentNotNull(tags, nameof(tags)); | ||||
| Safe.ArgumentNotNull(alphabet, nameof(alphabet)); | ||||
| m_dfa = dfaTable; | ||||
| m_final = finalStates; | ||||
| m_tags = tags; | ||||
| m_initialState = initialState; | ||||
| m_alphabet = alphabet; | ||||
| } | ||||
| public TTag Tag { | ||||
| [MethodImpl(MethodImplOptions.AggressiveInlining)] | ||||
| get { | ||||
| return m_tags[m_state]; | ||||
| } | ||||
| } | ||||
| public int Position { | ||||
| [MethodImpl(MethodImplOptions.AggressiveInlining)] | ||||
| get { | ||||
| return m_position; | ||||
| } | ||||
| } | ||||
| public bool IsFinal { | ||||
| [MethodImpl(MethodImplOptions.AggressiveInlining)] | ||||
| get { | ||||
| return m_final[m_state]; | ||||
| } | ||||
| } | ||||
| [MethodImpl(MethodImplOptions.AggressiveInlining)] | ||||
| public void ResetState() { | ||||
| m_state = m_initialState; | ||||
| } | ||||
| public InputScanner<TTag> Clone() { | ||||
| var clone = new InputScanner<TTag>(m_dfa, m_final, m_tags, m_initialState, m_alphabet); | ||||
| clone.m_state = m_state; | ||||
| clone.m_position = m_position; | ||||
| return clone; | ||||
| } | ||||
| //[MethodImpl(MethodImplOptions.AggressiveInlining)] | ||||
| public bool Scan(char[] data, int offset, int max) { | ||||
| var next = m_state; | ||||
| while(offset < max) { | ||||
| next = m_dfa[next, m_alphabet.Translate(data[offset])]; | ||||
| if (next == AutomatonConst.UnreachableState) { | ||||
| // scanner stops on the next position after last recognized symbol | ||||
| m_position = offset; | ||||
| return false; | ||||
| } | ||||
| m_state = next; | ||||
| offset++; | ||||
| } | ||||
| m_position = offset; | ||||
| return true; | ||||
| } | ||||
| } | ||||
| } | ||||