library-ts/browser/text/lexer/LexerQuery.ts

import { BooleanExpression } from "../../expressions/BooleanExpression";
import { LexerEvent } from "./LexerEvent";


export class LexerQuery
{
  source:string;
  tokens:LexerEvent[];

  _index:Map<LexerEvent,number> = new Map<LexerEvent,number>();

  createTokenIndex()
  {
    for ( let i = 0; i < this.tokens.length; i++ )
    {
      this.tokens[ i ].getMatch( this.source );
      this._index.set( this.tokens[ i ], i );
    }
  }

  createReplacedOutput( replacements:Map<LexerEvent,string> )
  {
    let output = [];
    
    for ( let i = 0; i < this.tokens.length; i++ )
    {
      let token = this.tokens[ i ];
      
      if ( token.isDone || token.isError )
      {
        continue;
      }

      if ( replacements.has( token ) )
      {
        output.push( replacements.get( token ) ); 
      }
      else
      {
        output.push( token.match );
      }
    }

    return output.join( "" );
  }
  
  linePosition( offset:number )
  {
    let lineIndex = 1;
    let lastLineBreak = 0;
    
    for ( let i = 0; i < offset; i++ )
    {
      if ( this.source[ i ] === "\n" || this.source === "\r" )
      {
        if ( this.source[ i ] === "\n" && this.source[ i + 1 ] === "\r" )
        {
          i++
        }

        lineIndex++;
        lastLineBreak = i;
      }
    }

    let characterIndex = offset - lastLineBreak;

    return { line: lineIndex, characterIndex: characterIndex }; 

  }

  lineInfo( l:LexerEvent, breaksBefore:number=2, breaksAfter:number=2 )
  {
    let startIndex = l.offset - 1;
    let endIndex   = l.offset + 1;

    let numLineBreakBeforeFound = 0;

    for ( let i = startIndex; i >= 0 && numLineBreakBeforeFound < breaksBefore; i-- )
    {
      if ( this.source[ i ] === "\n" || this.source[ i ] === "\r" )
      {
        if ( this.source[ i ] === "\n" && i > 0 && this.source[ i - 1 ] === "\r" ) 
        {
          i--;
        }

        numLineBreakBeforeFound ++;
        
      }
      else
      {
        startIndex = i;
      }
    }

    
    let numLineBreakAfterFound = 0;

    for ( let i = startIndex; i >= 0 && numLineBreakAfterFound < breaksAfter; i++ )
    {
      if ( this.source[ i ] === "\n" || this.source[ i ] === "\r" )
      {
        if ( this.source[ i ] === "\r" && i < ( this.source.length - 1 ) && this.source[ i + 1 ] === "\n" ) 
        {
          i++;
        }

        numLineBreakAfterFound ++;
        
      }
      else
      {
        endIndex = i;
      }
    }
    
    let info = this.source.substring( startIndex, endIndex );

    return info;
  }

  index( l:LexerEvent )
  {
    return this._index.get( l );
  }

  all( matcher:BooleanExpression<LexerEvent> ):LexerEvent[]
  {
    let output:LexerEvent[] = [];

    for ( let i = 0; i < this.tokens.length; i++ )
    {
      if ( matcher.evaluate( this.tokens[ i ] ) )
      {
        output.push( this.tokens[ i ] );
      }
    }

    return output;
  }

  forAllMatches( index:number, end:number, callback:(s:string)=>void)
  {
    for ( let i = index; i <= end; i++ )
    {
      callback( this.tokens[ i ].match );
    }
  }

  forAllWithType( type:string, callback:( t:LexerEvent )=>void )
  {
    for ( let i =0; i < this.tokens.length; i++ )
    {
      if ( ! this.tokens[ i ].isType( type ) )
      {
        continue;
      }

      callback( this.tokens[ i ] );
    }
  }

  searchBlockIndices( index:number, start:BooleanExpression<LexerEvent>, end:BooleanExpression<LexerEvent>)
  {
    let startIndex = -1;

    let numOpen = 0;
    let blocksFound = false;

    for ( let i = index; i < this.tokens.length; i++ )
    {
      let token = this.tokens[ i ];
      
      if ( start.evaluate( token ) )
      {
        if ( ! blocksFound )
        {
          startIndex = i;
          blocksFound = true;
        }

        numOpen ++;
      }

      if ( end.evaluate( token ) )
      {
        numOpen --;
        
        if ( numOpen < 0 )
        {
          return null;
        }

        if ( numOpen === 0 )
        {
          return { startIndex, endIndex: i, length: ( 1 + i - startIndex ) };
        }
      }
    }

    return null;
  }

  searchIndex( index:number, forward:boolean, matcher:BooleanExpression<LexerEvent>, ignore?:BooleanExpression<LexerEvent>, maxItems:number=100000  )
  { 
    let itemCount = 0;

    if ( forward )
    {
      let next = index + 1;

      for ( let i = next; i < this.tokens.length && itemCount < maxItems; i++, itemCount++ )
      {
        let token = this.tokens[ i ];
        
        if ( ignore && ignore.evaluate( token ) )
        {
          continue;
        }

        if ( matcher.evaluate( token ) )
        {
          return i;
        }

        itemCount++;
      }
    }
    else
    {
      let previous = index - 1;
      
      for ( let i = previous; i >=0 && itemCount < maxItems; i--, itemCount++ )
      {
        let token = this.tokens[ i ];
        
        if ( ignore && ignore.evaluate( token ) )
        {
          continue;
        }

        if ( matcher.evaluate( token ) )
        {
          return i;
        }

        itemCount++;
      }
    }

    return -1;
  }

  searchItem( index:number, forward:boolean, matcher:BooleanExpression<LexerEvent>, ignore?:BooleanExpression<LexerEvent>, maxItems:number = 100000  )
  {
    let nextIndex = this.searchIndex( index, forward, matcher, ignore );

    return nextIndex === -1 ? null : this.tokens[ nextIndex ];
  }
}