analisis.py

import ply.lex as lex

# list of tokens
tokens = (

	# Reserverd words
	'ELSE',
	'IF',
	'INT',
	'RETURN',
	'VOID',
	'WHILE',
	
	# Symbols
	'PLUS',
	'MINUS',
	'TIMES',
	'DIVIDE',
	'LESS',
	'LESSEQUAL',
	'GREATER',
	'GREATEREQUAL',
	'EQUAL',
	'DEQUAL',
	'DISTINT',
	'SEMICOLON',
	'COMMA',
	'LPAREN',
	'RPAREN',
	'LBRACKET',
	'RBRACKET',
	'LBLOCK',
	'RBLOCK',

	# Others	
	'ID',
	'NUMBER',
)

# Regular expressions rules for a simple tokens
t_PLUS 	 = r'\+'
t_MINUS	 = r'-'
t_TIMES  = r'\*'
t_DIVIDE = r'/'
t_EQUAL  = r'='
t_LESS 	 = r'<'
t_GREATER = r'>'
t_SEMICOLON = ';'
t_COMMA	 = r','
t_LPAREN = r'\('
t_RPAREN  = r'\)'
t_LBRACKET = r'\['
t_RBRACKET = r'\]'
t_LBLOCK   = r'{'
t_RBLOCK   = r'}'

def t_ELSE(t):
	r'else'
	return t

def t_IF(t):
	r'if'
	return t

def t_INT(t):
	r'int'
	return t
	
def t_RETURN(t):
	r'return'
	return t
	
def t_VOID(t):
	r'void'
	return t
	
def t_WHILE(t):
	r'while'
	return t
	
def t_NUMBER(t):
	r'\d+'
	t.value = int(t.value)
	return t

def t_ID(t):
	r'\w+(_\d\w)*'
	return t

def t_LESSEQUAL(t):
	r'<='
	return t

def t_GREATEREQUAL(t):
	r'>='
	return t

def t_DEQUAL(t):
	r'=='
	return t

def t_DISTINT(t):
	r'!='
	return t

def t_newline(t):
	r'\n+'
	t.lexer.lineno += len(t.value)

t_ignore = ' \t'

def t_comments(t):
	r'/\*(.|\n)*?\*/'
	t.lexer.lineno += t.value.count('\n')

def t_comments_C99(t):
	r'//(.)*?\n'
	t.lexer.lineno += 1

def t_error(t):
	print "Lexical error: " + str(t.value[0])
	t.lexer.skip(1)

def test(data, lexer):
	lexer.input(data)
	while True:
		tok = lexer.token()
		if not tok:
			break
		print tok

lexer = lex.lex()

# Test
if __name__ == '__main__':
	archi=open('eje.txt','r')
	line=""
	for linea in archi:
		line=line+linea
	archi.close()
	print line
	# Build lexer and try on
	lexer.input(line)
	test(line, lexer)