Class: NewickTokenizer

Inherits:
Object
  • Object
show all
Defined in:
lib/Newick.rb

Overview

Splits a Newick tree string into tokens that NewickTree uses

Instance Method Summary collapse

Constructor Details

#initialize(str) ⇒ NewickTokenizer

Returns a new instance of NewickTokenizer.



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# File 'lib/Newick.rb', line 23

def initialize(str)
  @str = str
  @pos = 0
end

Instance Method Details

#nextChar ⇒ Object

returns the next character in the string and updates position



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# File 'lib/Newick.rb', line 29

def nextChar
  if (@pos < @str.size)
    c = @str[@pos].chr
    @pos += 1
    return c
  else
    return nil
  end
end

#nextToken ⇒ Object

returns the next token in the string and updates position



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# File 'lib/Newick.rb', line 40

def nextToken
  c = nextChar
  if (c == " " || c == "\n" || c == "\r")
    return nextToken
  elsif (c == "(" || c == ")" || c == ',')
    return NewickToken.new("SYMBOL", c)
  elsif (c == ":")
    if (@str.index((/([0-9|\.|\-|e|E]+)/), @pos) == @pos)
	@pos += $1.length
	return NewickToken.new("WEIGHT", $1)
    else
	raise NewickParseError, "Illegal weight at pos #{@pos} of #{@str}"
    end
  elsif (c == "'")
    if (@str.index(/(\'[^\']*\')/, @pos - 1) == @pos - 1)
	@pos += $1.length - 1
	return NewickToken.new("LABEL", $1)
    else
	raise NewickParseError, "Illegal label at pos #{@pos} of #{@str}"
    end
  elsif (@str.index(/([^,():]+)/, @pos - 1) == @pos - 1)
    @pos += $1.length - 1
    return NewickToken.new("LABEL", $1)
  end
end

#peekToken ⇒ Object

returms the next token in the string without changing position



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# File 'lib/Newick.rb', line 67

def peekToken
  origPos = @pos
  token = nextToken
  @pos = origPos
  return token
end