Class: StringScanner

Inherits:
Object show all
Defined in:
opal/stdlib/strscan.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(string) ⇒ StringScanner

Returns a new instance of StringScanner.



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# File 'opal/stdlib/strscan.rb', line 5

def initialize(string)
  @string  = string
  @pos     = 0
  @matched = nil
  @working = string
  @match   = []
end

Instance Attribute Details

#matched ⇒ Object (readonly)

Returns the value of attribute matched.



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# File 'opal/stdlib/strscan.rb', line 3

def matched
  @matched
end

#pos ⇒ Object

Returns the value of attribute pos.



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# File 'opal/stdlib/strscan.rb', line 2

def pos
  @pos
end

#string ⇒ Object (readonly)

Returns the value of attribute string.



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# File 'opal/stdlib/strscan.rb', line 13

def string
  @string
end

Instance Method Details

#[](idx) ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 84

def [](idx)
  if @match.empty?
    return nil
  end
  case idx
  when Symbol
    idx = idx.to_s
  when String
    # noop
  else
    idx = Opal.coerce_to!(idx, Integer, :to_int)
  end
  %x{
    var match = #{@match};

    if (idx < 0) {
      idx += match.length;
    }

    if (idx < 0 || idx >= match.length) {
      return nil;
    }

    if (match[idx] == null) {
      return nil;
    }

    return match[idx];
  }
end

#beginning_of_line? ⇒ Boolean Also known as: bol?

Returns:



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# File 'opal/stdlib/strscan.rb', line 15

def beginning_of_line?
  `#{@pos} === 0 || #{@string}.charAt(#{@pos} - 1) === "\n"`
end

#check(pattern) ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 115

def check(pattern)
  pattern = anchor(pattern)

  %x{
    var result = pattern.exec(#{@working});

    if (result == null) {
      return #{@matched} = nil;
    }

    return #{@matched} = result[0];
  }
end

#check_until(pattern) ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 129

def check_until(pattern)
  %x{
    var prev_pos = #{@prev_pos},
        pos      = #{@pos};

    var result = #{scan_until(pattern)};

    if (result !== nil) {
      #{@matched} = result.substr(-1);
      #{@working} = #{@string}.substr(pos);
    }

    #{@prev_pos} = prev_pos;
    #{@pos}      = pos;

    return result;
  }
end

#eos? ⇒ Boolean

Returns:



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# File 'opal/stdlib/strscan.rb', line 152

def eos?
  `#{@working}.length === 0`
end

#exist?(pattern) ⇒ Boolean

Returns:



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# File 'opal/stdlib/strscan.rb', line 156

def exist?(pattern)
  %x{
    var result = pattern.exec(#{@working});

    if (result == null) {
      return nil;
    }
    else if (result.index == 0) {
      return 0;
    }
    else {
      return result.index + 1;
    }
  }
end

#get_byte ⇒ Object Also known as: getch 



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# File 'opal/stdlib/strscan.rb', line 212

def get_byte
  %x{
    var result = nil;

    if (#{@pos} < #{@string}.length) {
      #{@prev_pos}  = #{@pos};
      #{@pos}      += 1;
      result      = #{@matched} = #{@working}.substring(0, 1);
      #{@working}   = #{@working}.substring(1);
    }
    else {
      #{@matched} = nil;
    }

    return result;
  }
end

#match?(pattern) ⇒ Boolean

Returns:



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# File 'opal/stdlib/strscan.rb', line 233

def match?(pattern)
  pattern = anchor(pattern)

  %x{
    var result = pattern.exec(#{@working});

    if (result == null) {
      return nil;
    }
    else {
      #{@prev_pos} = #{@pos};

      return result[0].length;
    }
  }
end

#matched_size ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 261

def matched_size
  %x{
    if (#{@matched} === nil) {
      return nil;
    }

    return #{@matched}.length
  }
end

#peek(length) ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 148

def peek(length)
  `#{@working}.substring(0, length)`
end

#post_match ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 271

def post_match
  %x{
    if (#{@matched} === nil) {
      return nil;
    }

    return #{@string}.substr(#{@pos});
  }
end

#pre_match ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 281

def pre_match
  %x{
    if (#{@matched} === nil) {
      return nil;
    }

    return #{@string}.substr(0, #{@prev_pos});
  }
end

#reset ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 291

def reset
  @working = @string
  @matched = nil
  @pos     = 0
end

#rest ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 297

def rest
  @working
end

#rest? ⇒ Boolean

Returns:



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# File 'opal/stdlib/strscan.rb', line 301

def rest?
  `#{@working}.length !== 0`
end

#rest_size ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 305

def rest_size
  rest.size
end

#scan(pattern) ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 21

def scan(pattern)
  pattern = anchor(pattern)

  %x{
    var result = pattern.exec(#{@working});

    if (result == null) {
      return #{@matched} = nil;
    }
    else if (typeof(result) === 'object') {
      #{@prev_pos} = #{@pos};
      #{@pos}     += result[0].length;
      #{@working}  = #{@working}.substring(result[0].length);
      #{@matched}  = result[0];
      #{@match}    = result;

      return result[0];
    }
    else if (typeof(result) === 'string') {
      #{@pos}     += result.length;
      #{@working}  = #{@working}.substring(result.length);

      return result;
    }
    else {
      return nil;
    }
  }
end

#scan_until(pattern) ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 51

def scan_until(pattern)
  pattern = anchor(pattern)

  %x{
    var pos     = #{@pos},
        working = #{@working},
        result;

    while (true) {
      result   = pattern.exec(working);
      pos     += 1;
      working  = working.substr(1);

      if (result == null) {
        if (working.length === 0) {
          #{@match} = [];
          return #{@matched} = nil;
        }

        continue;
      }

      #{@matched}  = #{@string}.substr(#{@pos}, pos - #{@pos} - 1 + result[0].length);
      #{@match}    = result;
      #{@prev_pos} = pos - 1;
      #{@pos}      = pos;
      #{@working}  = working.substr(result[0].length);

      return #{@matched};
    }
  }
end

#skip(pattern) ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 172

def skip(pattern)
  pattern = anchor(pattern)

  %x{
    var result = pattern.exec(#{@working});

    if (result == null) {
      #{@match} = [];
      return #{@matched} = nil;
    }
    else {
      var match_str = result[0];
      var match_len = match_str.length;

      #{@matched}   = match_str;
      #{@match}     = result;
      #{@prev_pos}  = #{@pos};
      #{@pos}      += match_len;
      #{@working}   = #{@working}.substring(match_len);

      return match_len;
    }
  }
end

#skip_until(pattern) ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 197

def skip_until(pattern)
  %x{
    var result = #{scan_until(pattern)};

    if (result === nil) {
      return nil;
    }
    else {
      #{@matched} = result.substr(-1);

      return result.length;
    }
  }
end

#terminate ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 309

def terminate
  @match = nil
  self.pos = @string.length
end

#unscan ⇒ Object 



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# File 'opal/stdlib/strscan.rb', line 314

def unscan
  @pos      = @prev_pos
  @prev_pos = nil
  @match    = nil

  self
end