Class: AjLisp::Lexer

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

Constant Summary collapse

@@separators = 
"()"

Instance Method Summary collapse

Constructor Details

#initialize(source) ⇒ Lexer

Returns a new instance of Lexer.



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# File 'lib/ajlisp/lexer.rb', line 7

def initialize(source)
	@source = source
	@tokens = []
end

Instance Method Details

#nextToken ⇒ Object 



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# File 'lib/ajlisp/lexer.rb', line 12

def nextToken
	if @tokens.length > 0
		return @tokens.pop
	end
	
	char = @source.nextChar
	
	while char and char =~ /\s/
		char = @source.nextChar
	end
	
	if char == nil
		return nil
	end
	
	if char == ?"
		return nextString
	end
	
	if @@separators.include? char
		return Token.new char, TokenType::SEPARATOR
	end

	if char =~ /\d/
		return nextInteger char
	end
       
       if char == ?. or char == ?@
           return nextSpecialAtom char
       end
	
	if char =~ /\w/
		return nextAtom char
	end
	
	if char == ?' or char == ?` or char == ?,
		return Token.new char, TokenType::ATOM
	end
	
	return nextSpecialAtom char
end

#pushToken(token) ⇒ Object 



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# File 'lib/ajlisp/lexer.rb', line 54

def pushToken(token)
	@tokens.push(token)
end