def visit_call_rvalue(self, callStmt):
if not self.sym_table.id_exists(callStmt.fun.lexeme):
message = "function " + callStmt.fun.lexeme + " not recognized"
raise error.MyPLError(message, callStmt.fun.line,
callStmt.fun.column)
temp = self.sym_table.get_info(callStmt.fun.lexeme)
if len(temp[0]) != len(callStmt.args):
raise error.MyPLError(
"wrong number of parameters " + callStmt.fun.lexeme,
callStmt.fun.line, callStmt.fun.column)
for i, x in enumerate(callStmt.args):
x.accept(self)
if (temp[0][i] != self.current_type.tokentype
and self.current_type.tokentype != token.NIL
): # and self.current_type.tokentype != token.ID):
message = "parameter " + str(i) + " is the wrong type" + temp[
0][i] + self.current_type.lexeme
raise error.MyPLError(message, self.current_type.line,
self.current_type.column)
self.current_type = callStmt.fun
self.current_type.tokentype = temp[1]
temp2 = self.current_type.tokentype
if temp2 == token.INTTYPE:
temp2 = token.INTVAL
elif temp2 == token.FLOATTYPE:
temp2 = token.FLOATVAL
elif temp2 == token.BOOLTYPE:
temp2 = token.BOOLVAL
elif temp2 == token.STRINGTYPE:
temp2 = token.STRINGVAL
self.current_type.tokentype = temp2
def visit_complex_expr(self, complExpr):
complExpr.first_operand.accept(self)
lhs = self.current_type
complExpr.rest.accept(self)
rhs = self.current_type
if lhs.tokentype != rhs.tokentype or lhs.tokentype == token.BOOLVAL or lhs.tokentype == token.NIL:
message = "cant combine a " + lhs.tokentype + " to a " + rhs.tokentype
raise error.MyPLError(message, rhs.line, lhs.column)
if complExpr.math_rel.lexeme != '+' and lhs.tokentype == token.STRINGVAL:
message = "can only add a " + lhs.tokentype + " to a " + rhs.tokentype
raise error.MyPLError(message, rhs.line, lhs.column)
self.current_type = lhs
def visit_bool_expr(self, boolStmt):
boolStmt.first_expr.accept(self)
lhs = self.current_type
if boolStmt.bool_rel != None:
boolStmt.second_expr.accept(self)
rhs = self.current_type
if lhs.tokentype != rhs.tokentype and rhs.tokentype != token.NIL:
message = "cant compare a " + lhs.tokentype + " with a " + rhs.tokentype
raise error.MyPLError(message, rhs.column, rhs.line)
if boolStmt.bool_rel.lexeme != "!=" and boolStmt.bool_rel.lexeme != "==" and rhs.tokentype == token.NIL:
raise error.MyPLError("can only check if == or != with nil",
rhs.line, rhs.column)
if boolStmt.bool_connector != None:
boolStmt.rest.accept(self)
def visit_new_rvalue(self, newStmt):
if not self.sym_table.id_exists(newStmt.struct_type.lexeme):
message = newStmt.struct_type.lexeme + " does not exist"
raise error.MyPLError(message, newStmt.struct_type.column,
newStmt.struct_type.line)
self.current_type = newStmt.struct_type
self.current_type.tokentype = newStmt.struct_type.lexeme
def visit_var_decl_stmt(self, var_decl):
var_decl.var_expr.accept(self)
exp_type = self.current_type.lexeme
var_id = var_decl.var_id
curr_env = self.sym_table.get_env_id()
# check that variable isn't already defined
if self.sym_table.id_exists_in_env(var_id.lexeme, curr_env):
msg = 'variable already defined in current environment'
self.__error(msg, var_id)
lhs = var_decl.var_type
#if not self.sym_table.id_exists(var_decl.var_id.lexeme):
self.sym_table.add_id(var_decl.var_id.lexeme)
var_decl.var_expr.accept(self)
rhs = self.current_type
if var_decl.var_type != None:
check = False
if lhs.tokentype == token.INTTYPE:
lhs = token.INTVAL
elif lhs.tokentype == token.STRINGTYPE:
lhs = token.STRINGVAL
elif lhs.tokentype == token.FLOATTYPE:
lhs = token.FLOATVAL
elif lhs.tokentype == token.BOOLTYPE:
lhs = token.BOOLVAL
elif lhs.tokentype == token.ID:
if not self.sym_table.id_exists(lhs.lexeme):
message = lhs.lexeme + " does not exist"
raise error.MyPLError(message, lhs.column, lhs.line)
lhs = lhs.lexeme
self.sym_table.set_info(var_decl.var_id.lexeme, lhs)
if lhs != rhs.tokentype and rhs.tokentype != token.NIL:
message = "cant assign a " + rhs.tokentype + " to a " + lhs
raise error.MyPLError(message, rhs.line, rhs.column)
if self.inStruct:
self.dict[var_decl.var_id.lexeme] = lhs
else:
self.sym_table.set_info(var_decl.var_id.lexeme, rhs.tokentype)
if rhs.tokentype == token.NIL:
raise error.MyPLError(
"can only assign a nil to an explicitly defined variable",
rhs.line, rhs.column)
if self.inStruct:
self.dict[var_decl.var_id.lexeme] = rhs.tokentype
def visit_assign_stmt(self, assign_stmt):
assign_stmt.lhs.accept(self)
lhs_type = self.current_type
assign_stmt.rhs.accept(self)
rhs_type = self.current_type.tokentype
temp = self.current_type
if rhs_type != token.NIL and rhs_type != lhs_type:
msg = 'mismatch type in assignment ' + lhs_type + " " + rhs_type
raise error.MyPLError(msg, temp.line, temp.column)
def visit_simple_rvalue(self, rvalue):
self.current_type = rvalue.val
if rvalue.val.tokentype == token.ID:
if not self.sym_table.id_exists(rvalue.val.lexeme):
message = rvalue.val.lexeme + " does not exist"
raise error.MyPLError(message, rvalue.val.column,
rvalue.val.line)
temp = self.sym_table.get_info(rvalue.val.lexeme)
self.current_type = copy.deepcopy(rvalue.val)
self.current_type.tokentype = temp
def __type(self):
"""<type> ::= ID | INTTYPE | FLOATTYPE | BOOLTYPE | STRINGTYPE"""
types = [token.ID, token.INTTYPE, token.FLOATTYPE, token.BOOLTYPE]
types.append(token.STRINGTYPE)
if self.current_token.tokentype in types:
self.__advance()
else:
s = 'expected a type, found"' + self.current_token.lexeme + '" in parser'
l = self.current_token.line
c = self.current_token.column
raise error.MyPLError(s, l, c)
def visit_lvalue(self, lvalueStmt):
if len(lvalueStmt.path) == 1:
temp = lvalueStmt.path[-1].lexeme
if not self.sym_table.id_exists(temp):
message = temp + " is not initialized"
raise error.MyPLError(message, lvalueStmt.path[-1].line,
lvalueStmt.path[-1].column)
self.current_type = self.sym_table.get_info(temp)
else:
temp = lvalueStmt.path[0].lexeme
if not self.sym_table.id_exists(temp):
message = temp + "- does not exist"
raise error.MyPLError(message, lvalueStmt.path[i].line,
lvalueStmt.path[i].column)
temp2 = self.sym_table.get_info(temp)
i = 1
j = len(lvalueStmt.path)
while i < j - 1:
if not self.sym_table.id_exists(temp2):
message = temp + "- does not exist"
raise error.MyPLError(message, lvalueStmt.path[i].line,
lvalueStmt.path[i].column)
temp = self.sym_table.get_info(temp2)
type = temp[lvalueStmt.path[i].lexeme]
temp2 = type
i += 1
#added this section in hw7 to get proper type
temp = self.sym_table.get_info(temp2)
temp2 = temp[lvalueStmt.path[-1].lexeme]
if temp2 == token.INTTYPE:
temp2 = token.INTVAL
elif temp2 == token.FLOATTYPE:
temp2 = token.FLOATVAL
elif temp2 == token.BOOLTYPE:
temp2 = token.BOOLVAL
elif temp2 == token.STRINGTYPE:
temp2 = token.STRINGVAL
#self.current_type = lvalueStmt.path[-1]
self.current_type = temp2
def visit_id_rvalue(self, idrVal):
if len(idrVal.path) == 1:
if not self.sym_table.id_exists(idrVal.path[0].lexeme):
message = idrVal.path[0].lexeme + " does not exist"
raise error.MyPLError(message, idrVal.path[0].column,
idrVal.path[0].line)
temp = self.sym_table.get_info(idrVal.path[0].lexeme)
self.current_type = idrVal.path[0]
self.current_type.tokentype = temp
else:
temp = idrVal.path[0].lexeme
if not self.sym_table.id_exists(temp):
message = temp + "- does not exist"
raise error.MyPLError(message, idrVal.path[i].line,
idrVal.path[i].column)
temp2 = self.sym_table.get_info(temp)
i = 1
j = len(idrVal.path)
while i < j - 1:
if not self.sym_table.id_exists(temp2):
message = temp + " - does not exist"
raise error.MyPLError(message, idrVal.path[i].line,
idrVal.path[i].column)
temp = self.sym_table.get_info(temp2)
type = temp[idrVal.path[i].lexeme]
temp2 = type
i += 1
temp = self.sym_table.get_info(temp2)
temp2 = temp[idrVal.path[-1].lexeme]
if temp2 == token.INTTYPE:
temp2 = token.INTVAL
elif temp2 == token.FLOATTYPE:
temp2 = token.FLOATVAL
elif temp2 == token.BOOLTYPE:
temp2 = token.BOOLVAL
elif temp2 == token.STRINGTYPE:
temp2 = token.STRINGVAL
self.current_type = idrVal.path[-1]
self.current_type.tokentype = temp2
def __mathrel(self):
"""<mathrel> ::= PLUS | MINUS | DIVIDE | MULTIPLY | MODULO"""
types = [token.PLUS, token.MINUS, token.DIVIDE, token.MULTIPLY, token.MODULO]
if self.current_token.tokentype in types:
temp_token = self.current_token
self.__advance()
return temp_token
else:
s = 'expected a math operator, found "' + self.current_token.lexeme + '" in parser'
l = self.current_token.line
c = self.current_token.column
raise error.MyPLError(s, l, c)
def __boolrel(self):
"""<boolrel> ::= EQUAL | LESS_THAN | GREATER_THAN | LESS_THAN_EQUAL |"""
""" GREATER_THAN_EQUAL | NOT_EQUAL"""
types = [token.EQUAL, token.LESS_THAN, token.LESS_THAN_EQUAL]
types.extend([token.GREATER_THAN_EQUAL, token.GREATER_THAN])
types.append(token.NOT_EQUAL)
if self.current_token.tokentype in types:
self.__advance()
else:
s = 'expected a conditional operator, found "' + self.current_token.lexeme + '" in parser'
l = self.current_token.line
c = self.current_token.column
raise error.MyPLError(s, l, c)
def __rvalue(self):
"""<rvalue> ::= STRINGVAL | INTVAL | BOOLVAL | FLOATVAL | NIL | NEW ID | <idrval>"""
types = [token.STRINGVAL, token.INTVAL, token.BOOLVAL]
types.extend([token.FLOATVAL, token.NIL])
if self.current_token.tokentype == token.NEW:
self.__advance()
self.__eat(token.ID, "expecting an identifier")
elif self.current_token.tokentype == token.ID:
self.__idrval()
elif self.current_token.tokentype in types:
self.__advance()
else:
s = 'expected a rvalue found"' + self.current_token.lexeme + '" in parser'
l = self.current_token.line
c = self.current_token.column
raise error.MyPLError(s, l, c)
def __rvalue(self):
"""<rvalue> ::= STRINGVAL | INTVAL | BOOLVAL | FLOATVAL | NIL | NEW ID | <idrval>"""
types = [token.STRINGVAL, token.INTVAL, token.BOOLVAL]
types.extend([token.FLOATVAL, token.NIL])
if self.current_token.tokentype == token.NEW:
new_r_value_node = ast.NewRValue()
self.__advance()
new_r_value_node.struct_type = self.current_token
self.__eat(token.ID, "expecting an identifier")
return new_r_value_node
elif self.current_token.tokentype == token.ID:
return self.__idrval()
elif self.current_token.tokentype in types:
simple_rvalue_node = ast.SimpleRValue()
simple_rvalue_node.val = self.current_token
self.__advance()
return simple_rvalue_node
else:
s = 'expected a rvalue found"' + self.current_token.lexeme + '" in parser'
l = self.current_token.line
c = self.current_token.column
raise error.MyPLError(s, l, c)
def visit_fun_decl_stmt(self, funStmt):
self.sym_table.add_id(funStmt.fun_name.lexeme)
param = []
paramNames = []
type = []
self.sym_table.push_environment()
for x in funStmt.params:
x.accept(self)
if self.current_type.lexeme in paramNames:
message = "cant have parameters with the same name" + self.current_type.lexeme
raise error.MyPLError(message, self.current_type.column,
self.current_type.line)
param.append(self.current_type.tokentype)
paramNames.append(self.current_type.lexeme)
type.append(param)
temp2 = funStmt.return_type.tokentype
if temp2 == token.INTTYPE:
temp2 = token.INTVAL
elif temp2 == token.FLOATTYPE:
temp2 = token.FLOATVAL
elif temp2 == token.BOOLTYPE:
temp2 = token.BOOLVAL
elif temp2 == token.STRINGTYPE:
temp2 = token.STRINGVAL
if funStmt.return_type.tokentype != token.ID:
type.append(funStmt.return_type.tokentype)
else:
type.append(funStmt.return_type.lexeme)
self.sym_table.set_info(funStmt.fun_name.lexeme, type)
temp = self.sym_table.get_info("return")
self.sym_table.set_info("return", funStmt.return_type.tokentype)
for x in funStmt.stmt_list.stmts:
self.current_type = None
x.accept(self)
self.sym_table.pop_environment()
self.sym_table.set_info("return", temp)
def next_token(self):
curSymbol = ''
#Remove spaces
if (self.__peek() == ' '):
while (self.__peek() == ' '):
self.__read()
self.column += 1
#Remove newlines if found
if (self.__peek() == '\n'):
while (self.__peek() == '\n'):
self.__read()
self.line += 1
self.column = 0
#If I see a comment, get to the next line
if (self.__peek() == '#'):
while (self.__peek() != '\n' and self.__peek() != ''):
self.__read()
self.column += 1
if (self.__read() != ''):
self.line += 1
self.column = 0
return self.next_token()
#If there is a letter, get the whole identifyer
if (self.__peek().isalpha()):
while (self.__peek().isalpha() or self.__peek().isdigit()
or self.__peek() == '_'):
curSymbol += self.__read()
self.column += 1
#If there are double quotes, get the whole string
elif (self.__peek() == '"'):
curSymbol += self.__read()
self.column += 1
#Keep reading in the string until the next double quotes are found
while (self.__peek() != '"' and self.__peek() != '\n'):
curSymbol += self.__read()
self.column += 1
#Check to see if there was a newline or missing closing quote
if (self.__peek() == '\n'):
raise error.MyPLError("reached newline reading string",
self.line, self.column + 1)
elif (self.__peek() != '"'):
raise error.MyPLError('missing closing quotes', self.line,
self.column + 1)
else:
curSymbol += self.__read()
self.column += 1
#If there is a digit, get the whole number
elif (self.__peek().isdigit()):
#Keep reading until you do not find any more digits
while (self.__peek().isdigit()):
curSymbol += self.__read()
self.column += 1
if (curSymbol == '0' and self.__peek().isdigit()):
raise error.MyPLError(
'unexpeted symbol "%s"' % self.__peek(), self.line,
self.column + 1)
#If theres a period, it's a float.
if (self.__peek() == '.'):
curSymbol += self.__read()
self.column += 1
changed = 0
#Keep reading digits after the period
while (self.__peek().isdigit()):
curSymbol += self.__read()
self.column += 1
changed = 1
if (self.__peek().isalpha()):
raise error.MyPLError(
'unexpected symbol "%s"' % self.__peek(), self.line,
self.column + 1)
#Make sure there are digits after the decimal
if (changed == 0):
raise error.MyPLError("missing digit in float value",
self.line, self.column + 1)
#Make sure there is only one decimal point
elif (self.__peek() == '.'):
raise error.MyPLError(
"Too many decimal points in float value", self.line,
self.column + 1)
elif (self.__peek().isalpha()):
raise error.MyPLError('unexpcted symbol "%s"' % self.__peek(),
self.line, self.column + 1)
#If nothing above was triggerd,
#the next symbol is punctuation or EOS
else:
curSymbol += self.__read()
#If the symbol is EOS, do not increment the colmumn
if (curSymbol == '!' and self.__peek() != '='):
error.MyPLError('missing "=" after "!"', self.line,
self.column)
if (curSymbol != ''):
self.column += 1
#Check to see if the symbol is >=, <=, ==, or != and include the =
#second equals sign and incriment the column
if ((curSymbol == '>' or curSymbol == '=' or curSymbol == '!'
or curSymbol == '<') and self.__peek() == '='):
curSymbol += self.__read()
self.column += 1
#Check the current symbol against all possibilities and return
#a token of the correct type
if (curSymbol == ''):
return token.Token(token.EOS, curSymbol, self.line, self.column)
elif (curSymbol == '='):
return token.Token(token.ASSIGN, curSymbol, self.line, self.column)
elif (curSymbol == ','):
return token.Token(token.COMMA, curSymbol, self.line, self.column)
elif (curSymbol == ':'):
return token.Token(token.COLON, curSymbol, self.line, self.column)
elif (curSymbol == '/'):
return token.Token(token.DIVIDE, curSymbol, self.line, self.column)
elif (curSymbol == '.'):
return token.Token(token.DOT, curSymbol, self.line, self.column)
elif (curSymbol == '=='):
return token.Token(token.EQUAL, curSymbol, self.line,
self.column - 1)
elif (curSymbol == '>'):
return token.Token(token.GREATER_THAN, curSymbol, self.line,
self.column)
elif (curSymbol == '>='):
return token.Token(token.GREATER_THAN_EQUAL, curSymbol, self.line,
self.column - 1)
elif (curSymbol == '<'):
return token.Token(token.LESS_THAN, curSymbol, self.line,
self.column)
elif (curSymbol == '<='):
return token.Token(token.LESS_THAN_EQUAL, curSymbol, self.line,
self.column - 1)
elif (curSymbol == '!='):
return token.Token(token.NOT_EQUAL, curSymbol, self.line,
self.column - 1)
elif (curSymbol == '('):
return token.Token(token.LPAREN, curSymbol, self.line, self.column)
elif (curSymbol == ')'):
return token.Token(token.RPAREN, curSymbol, self.line, self.column)
elif (curSymbol == '-'):
return token.Token(token.MINUS, curSymbol, self.line, self.column)
elif (curSymbol == '%'):
return token.Token(token.MODULO, curSymbol, self.line, self.column)
elif (curSymbol == '*'):
return token.Token(token.MULTIPLY, curSymbol, self.line,
self.column)
elif (curSymbol == '+'):
return token.Token(token.PLUS, curSymbol, self.line, self.column)
elif (curSymbol == ';'):
return token.Token(token.SEMICOLON, curSymbol, self.line,
self.column)
elif (curSymbol == 'bool'):
return token.Token(token.BOOLTYPE, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'int'):
return token.Token(token.INTTYPE, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'float'):
return token.Token(token.FLOATTYPE, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'string'):
return token.Token(token.STRINGTYPE, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'struct'):
return token.Token(token.STRUCTTYPE, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'and'):
return token.Token(token.AND, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'or'):
return token.Token(token.OR, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'not'):
return token.Token(token.NOT, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'while'):
return token.Token(token.WHILE, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'do'):
return token.Token(token.DO, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'if'):
return token.Token(token.IF, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'then'):
return token.Token(token.THEN, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'else'):
return token.Token(token.ELSE, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'elif'):
return token.Token(token.ELIF, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'end'):
return token.Token(token.END, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'fun'):
return token.Token(token.FUN, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'var'):
return token.Token(token.VAR, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'set'):
return token.Token(token.SET, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'return'):
return token.Token(token.RETURN, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'new'):
return token.Token(token.NEW, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'nil'):
return token.Token(token.NIL, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol == 'true' or curSymbol == 'false'):
return token.Token(token.BOOLVAL, curSymbol, self.line,
self.column - len(curSymbol) + 1)
elif ('"' in curSymbol):
return token.Token(token.STRINGVAL,
curSymbol[1:len(curSymbol) - 1], self.line,
self.column - len(curSymbol) + 1)
elif (curSymbol[0].isdigit()):
if ('.' in curSymbol):
return token.Token(token.FLOATVAL, curSymbol, self.line,
self.column - len(curSymbol) + 1)
else:
return token.Token(token.INTVAL, curSymbol, self.line,
self.column - len(curSymbol) + 1)
else:
return token.Token(token.ID, curSymbol, self.line,
self.column - len(curSymbol) + 1)
def __error(self, error_msg, error_token):
s = error_msg + ', found "' + error_token.lexeme + '" in type checker'
l = error_token.line
c = error_token.column
raise error.MyPLError(s, l, c)
def __error(self, error_msg):
s = error_msg + ', found "' + self.current_token.lexeme + '" in parser'
l = self.current_token.line
c = self.current_token.column
raise error.MyPLError(s, l, c)
def next_token(self):
peekValue = self.__peek() # for efficiency purposes
# check the next character and act from there
# if EOS, return EOS token
if peekValue == "":
return token.Token(token.EOS, "", self.line, self.column)
# if digit, determine if float or int, then return
elif peekValue.isdigit():
curr_lexeme = self.__read()
# used to ensure a float only contains one decimal point
isFloat = False
# read until it's another important character in MyPL or whitespace because people might not put whitespace (ex. x=x+5; )
# if there is a non-digit character, we'll raise an error in the loop
while self.__peek(
) not in ';=+-*/%<>(),"' and not self.__peek().isspace():
# if not digit or decimal, error
if not self.__peek().isdigit() and self.__peek() != ".":
raise error.MyPLError(
'unexpected symbol "' + self.__peek() + '"', self.line,
self.column)
# if decimal point, ensure this is the first one and that the first half of the number is a valid intval
elif self.__peek() == "." and not isFloat:
if len(curr_lexeme) == 1 or (curr_lexeme[0] != "0"
and len(curr_lexeme) > 1):
isFloat = True
else:
raise error.MyPLError(
"float starts with invalid int", self.line,
self.column - (len(curr_lexeme) - 1))
elif self.__peek() == "." and isFloat:
raise error.MyPLError("two decimal points in one number",
self.line, self.column)
# if all is well, read the character
curr_lexeme += self.__read()
# after we have the whole number,
# verify it's valid and return the corresponding token
if isFloat:
# if there is nothing after the decimal point
if curr_lexeme[-1] == ".":
raise error.MyPLError(
"missing digit in float value", self.line, self.column
) # +1 to column to show where digit needs to be
else:
return token.Token(token.FLOATVAL, float(curr_lexeme),
self.line,
self.column - (len(curr_lexeme) - 1))
else:
# check if valid intval
if len(curr_lexeme) == 1 or (curr_lexeme[0] != "0"
and len(curr_lexeme) > 1):
return token.Token(token.INTVAL, int(curr_lexeme),
self.line,
self.column - (len(curr_lexeme) - 1))
else:
# this happens if the number is longer than one digit
# and starts with 0
# the unexpected symbol will always be the second digit,
# even if it's also 0
raise error.MyPLError(
'unexpected symbol "' + curr_lexeme[1] + '"',
self.line, self.column - (len(curr_lexeme) - 1))
# if alpha, determine if ID or keyword and return accordingly
elif peekValue.isalpha():
curr_lexeme = self.__read()
# expedites identification if the word has an underscore or digit
isDefinitelyID = False
# read until something that isn't alphanumeric or underscore
while self.__peek().isalpha() or self.__peek().isdigit(
) or self.__peek() == "_":
if self.__peek().isdigit() or self.__peek() == "_":
isDefinitelyID = True
curr_lexeme += self.__read()
# identify what keyword the token is, or if it's an ID
if isDefinitelyID:
return token.Token(token.ID, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "bool":
return token.Token(token.BOOLTYPE, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "int":
return token.Token(token.INTTYPE, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "float":
return token.Token(token.FLOATTYPE, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "string":
return token.Token(token.STRINGTYPE, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "struct":
return token.Token(token.STRUCTTYPE, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "and":
return token.Token(token.AND, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "or":
return token.Token(token.OR, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "not":
return token.Token(token.NOT, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "while":
return token.Token(token.WHILE, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "do":
return token.Token(token.DO, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "if":
return token.Token(token.IF, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "then":
return token.Token(token.THEN, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "else":
return token.Token(token.ELSE, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "elif":
return token.Token(token.ELIF, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "end":
return token.Token(token.END, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "fun":
return token.Token(token.FUN, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "var":
return token.Token(token.VAR, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "set":
return token.Token(token.SET, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "return":
return token.Token(token.RETURN, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "new":
return token.Token(token.NEW, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "nil":
return token.Token(token.NIL, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
elif curr_lexeme == "true" or curr_lexeme == "false":
return token.Token(token.BOOLVAL, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
else: # must be ID by process of elimination
return token.Token(token.ID, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1))
# if whitespace, read past it without doing anything
elif peekValue.isspace():
self.__read()
return self.next_token()
# if semicolon... (first because it's extremely common)
elif peekValue == ";":
self.__read()
return token.Token(token.SEMICOLON, ";", self.line, self.column)
# if quotes, return stringval token
# need to ensure the opening quotes are closed
elif peekValue == '"':
curr_lexeme = ""
self.__read() # throw out opening quotes
# read and stop before closing quotes or newline or EOS
while self.__peek() != '"' and self.__peek(
) != "\n" and self.__peek() != "":
curr_lexeme += self.__read()
if self.__peek() == '"': # if it ended with closing quotes
self.__read()
return token.Token(token.STRINGVAL, curr_lexeme, self.line,
self.column - (len(curr_lexeme) - 1) -
2) # -2 to account for quotes
elif self.__peek() == "\n":
raise error.MyPLError("reached newline reading string",
self.line, self.column)
elif self.__peek() == "":
raise error.MyPLError(
"reached EOS reading string", self.line, self.column + 1
) # +1 to column to show where the closing quotes should be
else:
raise error.MyPLError("something strange happened", self.line,
self.column)
# if comment, go until the end of the line/file without keeping anything
elif peekValue == "#":
while self.__peek() != "\n" and self.__peek() != "":
self.__read()
return self.next_token()
# if any other recognized character in MyPL
elif peekValue == "=":
self.__read()
if self.__peek() == "=": # if there is a second "="
self.__read()
return token.Token(token.EQUAL, "==", self.line,
self.column - 1)
else:
return token.Token(token.ASSIGN, "=", self.line, self.column)
elif peekValue == ",":
# reading here instead of in the return
# so that line and column update properly
self.__read()
return token.Token(token.COMMA, ",", self.line, self.column)
elif peekValue == ":":
self.__read()
return token.Token(token.COLON, ":", self.line, self.column)
elif peekValue == "/":
self.__read()
return token.Token(token.DIVIDE, "/", self.line, self.column)
elif peekValue == ".":
self.__read()
# a dot will never have numbers after it unless it's a float
# because IDs cannot start with numbers, and no keywords do either
# so if we got here, a dot with numbers after is a malformed float
if self.__peek().isdigit():
raise error.MyPLError("missing intval before decimal point",
self.line, self.column - 1)
else:
return token.Token(token.DOT, ".", self.line, self.column)
elif peekValue == ">":
self.__read()
if self.__peek() == "=": # if the next character is "="
self.__read()
return token.Token(token.GREATER_THAN_EQUAL, ">=", self.line,
self.column - 1)
else:
return token.Token(token.GREATER_THAN, ">", self.line,
self.column)
elif peekValue == "<":
self.__read()
if self.__peek() == "=": # if the next character is "="
self.__read()
return token.Token(token.LESS_THAN_EQUAL, "<=", self.line,
self.column - 1)
else:
return token.Token(token.LESS_THAN, "<", self.line,
self.column)
elif peekValue == "!":
self.__read()
if self.__peek() == "=":
self.__read()
return token.Token(token.NOT_EQUAL, "!=", self.line,
self.column - 1)
else:
raise error.MyPLError(
'unexpected symbol "!"', self.line, self.column -
1) # -1 to column to go back one since we read it already
elif peekValue == "(":
self.__read()
return token.Token(token.LPAREN, "(", self.line, self.column)
elif peekValue == ")":
self.__read()
return token.Token(token.RPAREN, ")", self.line, self.column)
elif peekValue == "-":
self.__read()
return token.Token(token.MINUS, "-", self.line, self.column)
elif peekValue == "%":
self.__read()
return token.Token(token.MODULO, "%", self.line, self.column)
elif peekValue == "*":
self.__read()
return token.Token(token.MULTIPLY, "*", self.line, self.column)
elif peekValue == "+":
self.__read()
return token.Token(token.PLUS, "+", self.line, self.column)
# if we reach this point, there is something very strange in the source
else:
raise error.MyPLError('unexpected symbol "' + peekValue + '"',
self.line, self.column)
def next_token(self):
symbol = ""
word = ""
tokenStartCol = self.column + 1
if (not self.__peek()):
return token.Token(token.EOS, "", self.line, tokenStartCol - 1)
symbol = self.__read()
word += symbol
self.column += 1
# ignore comment lines
if (symbol == "#"):
while (self.__peek() != "\n"):
self.__read()
self.__read()
self.column = 0
self.line += 1
return self.next_token()
if (symbol == "\n"):
self.line += 1
self.column = 0
return self.next_token()
if (symbol.isspace()):
return self.next_token()
if (symbol.isalpha()):
# any later characters, after a first alpha can be alphanumeric or '_'
while (self.__peek().isalpha() or self.__peek() == "_"
or self.__peek().isdigit()):
symbol = self.__read()
word += symbol
self.column += 1
# All alphabetic-only keywords appear here
if (word == 'and'):
return token.Token(token.AND, word, self.line, tokenStartCol)
elif (word == 'or'):
return token.Token(token.OR, word, self.line, tokenStartCol)
elif (word == 'not'):
return token.Token(token.NOT, word, self.line, tokenStartCol)
elif (word == 'while'):
return token.Token(token.WHILE, word, self.line, tokenStartCol)
elif (word == 'do'):
return token.Token(token.DO, word, self.line, tokenStartCol)
elif (word == 'if'):
return token.Token(token.IF, word, self.line, tokenStartCol)
elif (word == 'then'):
return token.Token(token.THEN, word, self.line, tokenStartCol)
elif (word == 'else'):
return token.Token(token.ELSE, word, self.line, tokenStartCol)
elif (word == 'elif'):
return token.Token(token.ELIF, word, self.line, tokenStartCol)
elif (word == 'end'):
return token.Token(token.END, word, self.line, tokenStartCol)
elif (word == 'fun'):
return token.Token(token.FUN, word, self.line, tokenStartCol)
elif (word == 'var'):
return token.Token(token.VAR, word, self.line, tokenStartCol)
elif (word == 'set'):
return token.Token(token.SET, word, self.line, tokenStartCol)
elif (word == 'return'):
return token.Token(token.RETURN, word, self.line,
tokenStartCol)
elif (word == 'new'):
return token.Token(token.NEW, word, self.line, tokenStartCol)
elif (word == 'nil'):
return token.Token(token.NIL, word, self.line, tokenStartCol)
elif (word == 'true' or word == 'false'):
return token.Token(token.BOOLVAL, word, self.line,
tokenStartCol)
elif (word == 'int'):
return token.Token(token.INTTYPE, word, self.line,
tokenStartCol)
elif (word == 'bool'):
return token.Token(token.BOOLTYPE, word, self.line,
tokenStartCol)
elif (word == 'float'):
return token.Token(token.FLOATTYPE, word, self.line,
tokenStartCol)
elif (word == 'string'):
return token.Token(token.STRINGTYPE, word, self.line,
tokenStartCol)
elif (word == 'struct'):
return token.Token(token.STRUCTTYPE, word, self.line,
tokenStartCol)
else:
return token.Token(token.ID, word, self.line, tokenStartCol)
if (symbol.isdigit()):
if (symbol == "0"):
if (self.__peek().isdigit()):
raise error.MyPLError(
'unexpected symbol "' + self.__peek() + '"', self.line,
tokenStartCol)
# floats cannot have more than one decimal
hasDotYet = False
while (self.__peek().isdigit() or self.__peek() == '.'):
symbol = self.__read()
word += symbol
self.column += 1
if (symbol == '.'):
if (hasDotYet):
raise error.MyPLError(
'unexpected symbol "' + self.__peek() + '"',
self.line, tokenStartCol)
hasDotYet = True
if (symbol == '.'):
# float ends in '.' and is invalid
raise error.MyPLError('missing digit in float value',
self.line, self.column + 1)
if (self.__peek().isalpha()):
raise error.MyPLError(
'unexpected symbol "' + self.__peek() + '"', self.line,
tokenStartCol)
if ('.' in word):
return token.Token(token.FLOATVAL, word, self.line,
tokenStartCol)
else:
return token.Token(token.INTVAL, word, self.line,
tokenStartCol)
# handle all string types
if (symbol == '"'):
while (self.__peek() and self.__peek() != '"'
and not self.__peek() == '\n'):
symbol = self.__read()
word += symbol
self.column += 1
if (not self.__peek() or self.__peek() == '\n'):
raise error.MyPLError("reached newline reading string",
self.line, self.column)
elif (self.__peek() == '"'):
word += self.__read()
self.column += 1
return token.Token(token.STRINGVAL, word[1:-1], self.line,
tokenStartCol)
if (symbol == '('):
return token.Token(token.LPAREN, symbol, self.line, tokenStartCol)
if (symbol == ')'):
return token.Token(token.RPAREN, symbol, self.line, tokenStartCol)
if (symbol == ','):
return token.Token(token.COMMA, symbol, self.line, tokenStartCol)
if (symbol == '%'):
return token.Token(token.MODULO, symbol, self.line, tokenStartCol)
if (symbol == '+'):
return token.Token(token.PLUS, symbol, self.line, tokenStartCol)
if (symbol == '-'):
return token.Token(token.MINUS, symbol, self.line, tokenStartCol)
if (symbol == ';'):
return token.Token(token.SEMICOLON, symbol, self.line,
tokenStartCol)
if (symbol == ':'):
return token.Token(token.COLON, symbol, self.line, tokenStartCol)
if (symbol == '*'):
return token.Token(token.MULTIPLY, symbol, self.line,
tokenStartCol)
if (symbol == '/'):
return token.Token(token.DIVIDE, symbol, self.line, tokenStartCol)
if (symbol == '.'):
return token.Token(token.DOT, symbol, self.line, tokenStartCol)
if (symbol == '='):
if (self.__peek() == '='):
symbol = self.__read()
word += symbol
self.column += 1
return token.Token(token.EQUAL, word, self.line, tokenStartCol)
else:
return token.Token(token.ASSIGN, symbol, self.line,
tokenStartCol)
if (symbol == '>'):
if (self.__peek() == '='):
symbol = self.__read()
word += symbol
self.column += 1
return token.Token(token.GREATER_THAN_EQUAL, word, self.line,
tokenStartCol)
else:
return token.Token(token.GREATER_THAN, symbol, self.line,
tokenStartCol)
if (symbol == '<'):
if (self.__peek() == '='):
symbol = self.__read()
word += symbol
self.column += 1
return token.Token(token.LESS_THAN_EQUAL, word, self.line,
tokenStartCol)
else:
return token.Token(token.LESS_THAN, symbol, self.line,
tokenStartCol)
if (symbol == '!'):
if (self.__peek() == '='):
symbol = self.__read()
word += symbol
self.column += 1
return token.Token(token.NOT_EQUAL, word, self.line,
tokenStartCol)
raise error.MyPLError('unexpected symbol "' + symbol + '"', self.line,
tokenStartCol)
def next_token(self):
symbol = self.__read()
#check EOF
if symbol == '':
return token.Token('EOS', symbol, self.line, self.column)
self.column += 1
#check space and skip over
if symbol == ' ':
return self.next_token()
#newline resets column and updates line
if symbol == '\n':
self.column = 0
self.line += 1
return self.next_token()
#skip over comments and increment line at the end
if symbol == '#':
while self.__peek() != '\n':
symbol += self.__read()
self.__read()
self.line += 1
self.column = 0
return self.next_token()
#checking 1 or 2 symbol characters
if symbol == '+':
return token.Token('PLUS', symbol , self.line, self.column)
elif symbol == '=':
if self.__peek() == '=':
symbol += self.__read()
self.column += 1
return token.Token('EQUAL', symbol , self.line, self.column - 1)
return token.Token('ASSIGN', symbol , self.line, self.column)
elif symbol == ',':
return token.Token('COMMA', symbol , self.line, self.column)
elif symbol == ':':
return token.Token('COLON', symbol , self.line, self.column)
elif symbol == '/':
return token.Token('DIVIDE', symbol , self.line, self.column)
elif symbol == '.':
return token.Token('DOT', symbol , self.line, self.column)
elif symbol == '>':
if self.__peek() == '=':
symbol += self.__read()
self.column += 1
return token.Token('GREATER_THAN_EQUAL', symbol , self.line, self.column - 1)
return token.Token('GREATER_THAN', symbol , self.line, self.column)
elif symbol == '<':
if self.__peek() == '=':
symbol += self.__read()
self.column += 1
return token.Token('LESS_THAN_EQUAL', symbol , self.line, self.column - 1)
return token.Token('LESS_THAN', symbol , self.line, self.column)
elif symbol == '(':
return token.Token('LPAREN', symbol , self.line, self.column)
elif symbol == ')':
return token.Token('RPAREN', symbol , self.line, self.column)
elif symbol == '-':
return token.Token('MINUS', symbol , self.line, self.column)
elif symbol == '%':
return token.Token('MODULO', symbol , self.line, self.column)
elif symbol == '*':
return token.Token('MULTIPLY', symbol , self.line, self.column)
elif symbol == ';':
return token.Token('SEMICOLON', symbol , self.line, self.column)
elif symbol == '!':
if self.__peek() == '=':
symbol += self.__read()
self.column += 1
return token.Token('NOT_EQUAL', symbol , self.line, self.column -1)
else:
raise error.MyPLError("Unexpected symbol '!'", self.line, self.column)
#check constants
#---------------
#check leading 0
if symbol == '0':
if self.__peek().isnumeric():
raise error.MyPLError("unexpected symbol '" + self.__peek() + "' ", self.line, self.column)
#get int/float value
if symbol.isnumeric():
while self.__peek().isnumeric():
symbol += self.__read()
self.column += 1
#check if poorly formed due to letters
if self.__peek().isalpha():
raise error.MyPLError("unexpected symbol '" + self.__peek() + "' ", self.line, self.column - (len(symbol) -1))
#check if floating point
if self.__peek() == '.':
symbol += self.__read()
self.column += 1
if not self.__peek().isnumeric():
raise error.MyPLError('Missingn digit in float value', self.line, self.column - (len(symbol) -1))
while self.__peek().isnumeric():
symbol += self.__read()
self.column += 1
#check letters in float
if self.__peek().isalpha():
raise error.MyPLError("unexpected symbol '" + self.__peek() + "' ", self.line, self.column - (len(symbol) -1))
return token.Token('FLOATVAL', symbol, self.line, self.column - (len(symbol) -1))
else:
return token.Token('INTVAL', symbol, self.line, self.column - (len(symbol) - 1))
#check if string value
if symbol == '"':
while self.__peek() != '"':
if self.__peek() == '\n':
raise error.MyPLError('Newline in middle of string', self.line, self.column - (len(symbol) - 1))
symbol += self.__read()
self.column += 1
if self.__peek() == '':
raise error.MyPLError('Missing " in string', self.line, self.column - (len(symbol) -1))
#read the ending "
self.__read()
self.column += 1
return token.Token('STRINGVAL', symbol[1:], self.line, self.column - (len(symbol)))
#get a string of alphabet characters
while self.__peek().isalpha() or self.__peek() == '_' or self.__peek().isnumeric():
symbol += self.__read()
self.column += 1
#check specical words
if symbol == 'bool':
return token.Token('BOOLTYPE', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'int':
return token.Token('INTTYPE', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'float':
return token.Token('FLOATTYPE', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'string':
return token.Token('STRINGTYPE', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'struct':
return token.Token('STRUCTTYPE', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'and':
return token.Token('AND', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'or':
return token.Token('OR', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'not':
return token.Token('NOT', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'while':
return token.Token('WHILE', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'do':
return token.Token('DO', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'if':
return token.Token('IF', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'then':
return token.Token('THEN', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'else':
return token.Token('ELSE', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'elif':
return token.Token('ELIF', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'end':
return token.Token('END', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'fun':
return token.Token('FUN', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'var':
return token.Token('VAR', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'set':
return token.Token('SET', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'return':
return token.Token('RETURN', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'new':
return token.Token('NEW', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'nil':
return token.Token('NIL', symbol, self.line, self.column - (len(symbol) - 1))
#BOOL values
elif symbol == 'true':
return token.Token('BOOLVAL', symbol, self.line, self.column - (len(symbol) - 1))
elif symbol == 'false':
return token.Token('BOOLVAL', symbol, self.line, self.column - (len(symbol) - 1))
#identifiers
if symbol[0].isalpha():
return token.Token('ID', symbol, self.line, self.column - (len(symbol) -1))
elif symbol[0] == '_':
raise error.MyPLError('Poorly formed identifier', self.line, self.column - (len(symbol) -1))
#unexpected char error
raise error.MyPLError("Unexpected character(s): '" + symbol + "'", self.line, self.column - (len(symbol) -1))
def __error(self, error_msg, target_token):
s = error_msg
l = target_token.line
c = target_token.column
raise error.MyPLError(s, l, c)
def next_token(self):
tokentype = token.ID
item = ''
isStringVal = False # makes sure that string values are set as string values
error_message = "Lexer Error "
while self.__peek().isspace():
# increments column for every character of whitespace found
if self.__peek() == " ":
self.column += 1
self.__read()
self.__comment_check()
if self.__peek() == '': # EOS end of file
tokentype = token.EOS
# special character such as plus or minus
if self.check_char() == 0:
self.column += 1
item += self.__read()
# checks for and invalid dot
if item == "." and str(self.__peek()).isnumeric():
error_message += "invalid float value"
e = error.MyPLError(error_message, self.line, self.column_index - 1)
raise e
# checks for comparison operators
if item == '=' or item == '>' or item == '<' or item == '!':
if self.__peek() == '=':
item += self.__read()
elif self.__peek() == '"': # string value
self.column += 1 # increments column to a tokens starting index
self.__read()
while self.__peek() != '"':
if self.__peek() == '\n':
error_message += "reached newline character in string"
e = error.MyPLError(error_message, self.line, self.column_index)
raise e
elif self.__peek() == '':
error_message += "reached EOS character in string"
e = error.MyPLError(error_message, self.line, self.column_index)
raise e
else:
item += self.__read()
self.__read()
tokentype = token.STRINGVAL
isStringVal = True;
else: # any other type of character
self.column += 1 # increments column to a tokens starting index
isnum = False # tracks if you are entering a number
item += self.__read()
# sets while loop to true if you are entering a number
if item.isnumeric():
isnum = True
if self.check_char() == 1:
# checks for characters that should end the token
# checks if a number starts with zero
# the previous if statement will check if the next
# character is a decimal point
if isnum and item == '0':
error_message += "unexpected symbol '" + str(self.__peek()) + "'"
e = error.MyPLError(error_message, self.line, self.column_index)
raise e
# runs until it reaches a character that marks the end of the token
while self.check_char() != 0 and self.__peek() != '"':
if isnum and not item.isnumeric():
error_message += "unexpected value '" + str(item[len(item) - 1]) + "'"
e = error.MyPLError(error_message, self.line, self.column_index - 1)
raise e
else:
self.__comment_check()
item += self.__read()
if not isStringVal:
if item == "string": # strips spaces
tokentype = token.STRINGTYPE
else:
item = item.strip()
if item.isnumeric() and tokentype != token.STRINGVAL: # int and float check
if self.__peek() == ".":
item += self.__read()
decimal = str(self.__peek())
if not decimal.isnumeric(): # checks for an invalid float character
error_message += "missing digit in float value"
e = error.MyPLError(error_message, self.line, self.column_index - 1)
raise e
while decimal.isnumeric and (self.check_char() != 0 or self.__peek() == "."):
decimal += self.__peek()
if not decimal.isnumeric() and self.__peek() != ";":
self.__peek()
error_message += "unexpected character '" + str(self.__peek()) + "'"
e = error.MyPLError(error_message, self.line, self.column_index + 1)
raise e
else:
item += self.__read()
item = item.strip()
if item.count('.', 0, len(item)):
tokentype = token.FLOATVAL
else:
tokentype = token.INTVAL
# checks if the token is a special character and sets token type accordingly
if not isStringVal:
if item == "=":
tokentype = token.ASSIGN
elif item == ",":
tokentype = token.COMMA
elif item == ":":
tokentype = token.COLON
elif item == "/":
tokentype = token.DIVIDE
elif item == ".":
tokentype = token.DOT
elif item == "==":
tokentype = token.EQUAL
elif item == ">":
tokentype = token.GREATER_THAN
elif item == ">=":
tokentype = token.GREATER_THAN_EQUAL
elif item == "<":
tokentype = token.LESS_THAN
elif item == "<=":
tokentype = token.LESS_THAN_EQUAL
elif item == "!=":
tokentype = token.NOT_EQUAL
elif item == "(":
tokentype = token.LPAREN
elif item == ")":
tokentype = token.RPAREN
elif item == "-":
tokentype = token.MINUS
elif item == "%":
tokentype = token.MODULO
elif item == "*":
tokentype = token.MULTIPLY
elif item == "+":
tokentype = token.PLUS
elif item == "true" or item == "false":
tokentype = token.BOOLVAL
elif item == ";":
tokentype = token.SEMICOLON
elif item == "bool":
tokentype = token.BOOLTYPE
elif item == "int":
tokentype = token.INTTYPE
elif item == "float":
tokentype = token.FLOATTYPE
elif item == "struct":
tokentype = token.STRUCTTYPE
elif item == "and":
tokentype = token.AND
elif item == "or":
tokentype = token.OR
elif item == "not":
tokentype = token.NOT
elif item == "while":
tokentype = token.WHILE
elif item == "do":
tokentype = token.DO
elif item == "if":
tokentype = token.IF
elif item == "then":
tokentype = token.THEN
elif item == "else":
tokentype = token.ELSE
elif item == "elif":
tokentype = token.ELIF
elif item == "end":
tokentype = token.END
elif item == "fun":
tokentype = token.FUN
elif item == "var":
tokentype = token.VAR
elif item == "set":
tokentype = token.SET
elif item == "return":
tokentype = token.RETURN
elif item == "new":
tokentype = token.NEW
elif item == "nil":
tokentype = token.NIL
final_token = token.Token(tokentype, item, self.line, self.column)
self.column = self.column_index # sets column to new value
if tokentype == token.EOS: # sets column to 0 at the end of the line
self.column = 0
return final_token
def next_token(self):
while self.__peek().isspace():
if self.__peek() == '\n':
self.line += 1
self.column = 0
self.__read()
self.column += 1
symbol = self.__read()
self.column += 1
if symbol == '#':
while not self.__peek() == '\n':
self.__read()
self.line += 1
self.__read()
return self.next_token()
if symbol == '':
return token.Token(token.EOS, '', self.line, self.column - 1)
elif symbol == '=':
if self.__peek() == '=':
symbol += self.__read()
col = self.column
self.column += 1
return token.Token(token.EQUAL, symbol, self.line, col)
else:
return token.Token(token.ASSIGN, symbol, self.line,
self.column)
elif symbol == ',':
return token.Token(token.COMMA, symbol, self.line, self.column)
elif symbol == ':':
return token.Token(token.COLON, symbol, self.line, self.column)
elif symbol == '/':
return token.Token(token.DIVIDE, symbol, self.line, self.column)
elif symbol == '.':
return token.Token(token.DOT, symbol, self.line, self.column)
elif symbol == '>':
if self.__peek() == '=':
symbol += self.__read()
col = self.column
self.column += 1
return token.Token(token.GREATER_THAN_EQUAL, symbol, self.line,
col)
else:
return token.Token(token.GREATER_THAN, symbol, self.line,
self.column)
elif symbol == '<':
if self.__peek() == '=':
symbol += self.__read()
col = self.column
self.column += 1
return token.Token(token.LESS_THAN_EQUAL, symbol, self.line,
col)
else:
return token.Token(token.LESS_THAN, symbol, self.line,
self.column)
elif symbol == '!':
if self.__peek() == '=':
symbol += self.__read()
col = self.column
self.column += 1
return token.Token(token.NOT_EQUAL, symbol, self.line, col)
elif symbol == '(':
return token.Token(token.LPAREN, symbol, self.line, self.column)
elif symbol == ')':
return token.Token(token.RPAREN, symbol, self.line, self.column)
elif symbol == '-':
return token.Token(token.MINUS, symbol, self.line, self.column)
elif symbol == '%':
return token.Token(token.MODULO, symbol, self.line, self.column)
elif symbol == '*':
return token.Token(token.MULTIPLY, symbol, self.line, self.column)
elif symbol == '+':
return token.Token(token.PLUS, symbol, self.line, self.column)
elif symbol == ';':
return token.Token(token.SEMICOLON, symbol, self.line, self.column)
elif symbol.isdigit():
flt = False
col = self.column - 1
if symbol == '0' and self.__peek().isdigit():
print(
error.MyPLError('unexpected number', self.line,
self.column))
exit()
while self.__peek().isdigit() or self.__peek() == ".":
symbol += self.__read()
self.column += 1
if symbol[-1] == ".":
if flt:
print(error.MyPLError('invalid number', self.line,
col))
exit()
elif not self.__peek().isdigit():
print(
error.MyPLError('missing digit in float value',
self.line, self.column))
exit()
else:
symbol += self.__read()
self.column += 1
flt = True
if self.__peek().isalpha():
print(
error.MyPLError('unexpected symbol', self.line,
self.column))
exit()
if flt:
return token.Token(token.FLOATVAL, symbol, self.line, col)
else:
return token.Token(token.INTVAL, symbol, self.line, col)
elif symbol == '"':
col = self.column - 1
if self.__peek() == '"':
symbol += self.__read()
self.column += 1
return token.Token(token.STRINGVAL, '', self.line, col)
symbol = self.__read()
while not self.__peek() == '"':
symbol += self.__read()
self.column += 1
if self.__peek() == '':
print("Improper string")
break
self.__read()
self.column += 1
return token.Token(token.STRINGVAL, symbol, self.line, col)
elif symbol.isalpha():
col = self.column - 1
while self.__peek().isalpha() or self.__peek().isdigit(
) or self.__peek() == '_':
symbol += self.__read()
self.column += 1
if symbol == 'and':
return token.Token(token.AND, symbol, self.line, col)
elif symbol == 'or':
return token.Token(token.OR, symbol, self.line, col)
elif symbol == 'not':
return token.Token(token.NOT, symbol, self.line, col)
elif symbol == 'bool':
return token.Token(token.BOOLTYPE, symbol, self.line, col)
elif symbol == 'int':
return token.Token(token.INTTYPE, symbol, self.line, col)
elif symbol == 'float':
return token.Token(token.FLOATTYPE, symbol, self.line, col)
elif symbol == 'string':
return token.Token(token.STRINGTYPE, symbol, self.line, col)
elif symbol == 'struct':
return token.Token(token.STRUCTTYPE, symbol, self.line, col)
elif symbol == 'while':
return token.Token(token.WHILE, symbol, self.line, col)
elif symbol == 'do':
return token.Token(token.DO, symbol, self.line, col)
elif symbol == 'if':
return token.Token(token.IF, symbol, self.line, col)
elif symbol == 'then':
return token.Token(token.THEN, symbol, self.line, col)
elif symbol == 'else':
return token.Token(token.ELSE, symbol, self.line, col)
elif symbol == 'elif':
return token.Token(token.ELIF, symbol, self.line, col)
elif symbol == 'end':
return token.Token(token.END, symbol, self.line, col)
elif symbol == 'fun':
return token.Token(token.FUN, symbol, self.line, col)
elif symbol == 'var':
return token.Token(token.VAR, symbol, self.line, col)
elif symbol == 'set':
return token.Token(token.SET, symbol, self.line, col)
elif symbol == 'return':
return token.Token(token.RETURN, symbol, self.line, col)
elif symbol == 'new':
return token.Token(token.NEW, symbol, self.line, col)
elif symbol == 'nil':
return token.Token(token.NIL, symbol, self.line, col)
elif symbol == 'true':
return token.Token(token.BOOLVAL, symbol, self.line, col)
elif symbol == 'false':
return token.Token(token.BOOLVAL, symbol, self.line, col)
else:
return token.Token(token.ID, symbol, self.line, col)
def __error(self, msg, the_token):
raise error.MyPLError(msg, the_token.line, the_token.column)
def next_token(self):
input = ""
oldLine = self.line
oldColumn = self.column
temp = ""
inputType = ""
intFloatOrString = 0 #1 if input is a number, 2 if float, 3 if string, 0 otherwise
checker = True
keepLooping = True
noSpaceSymbols = ['.', '<=', '>=', '==', '!=', '*',':', '/', '!', '+', '-', ';', '=', ')', '(', '<', '>', ',', '%'] #list of symbols that dont need whitesaces
comparisonsOp = ['<=', '>=', '==', '!=', '<', '>'] #list of comparisons
#take care of whitespace
while self.__peek().isspace(): # == " " or self.__peek() == '\n' or self.__peek == '\t':
temp = self.__read()
self.column += 1
oldColumn = self.column
while self.__peek() == '\n':
temp = self.__read()
self.column += 1
oldColumn = self.column
while self.__peek() != " " and self.__peek() != "" and self.__peek() != '\n' and not self.__peek().isspace() and keepLooping:
#token is a string
if self.__peek() == '"' or self.__peek() == "'":
isSingle = True;
if self.__peek() == '"':
isSingle = False
temp = self.__read()
self.column += 1
while (self.__peek() != "'" and self.__peek() != '"') or ((self.__peek() != "'" or not isSingle) and (self.__peek() != '"' or isSingle)):
input += self.__read()
if self.__peek() == '\n':
raise error.MyPLError("uh oh, you had a new line in a string ", self.line, self.column)
self.column += 1
temp = self.__read()
self.column += 1
intFloatOrString = 3
keepLooping = False
#token is not a string
#print(self.column)
#reads the next character
if keepLooping:
input += self.__read()
#what to do for comments
if input == '#':
while self.__peek() != '\n':
input = self.__read()
input = ""
temp == self.__read()
while self.__peek() == " " or self.__peek().isspace():
temp = self.__read()
while self.__peek() == '\n':
temp = self.__read()
self.line += 1
self.column = 1
oldLine = self.line
oldColumn = self.column
#bad number checking for number preceded by 0
if input == '0' and self.__peek().isdigit():
m = 'unexpected symbol "%s" at: ' %self.__peek()
raise error.MyPLError(m, self.line, self.column)
#bad number checking for digit followed by alphabetical letter
if input.isdigit() and self.__peek().isalpha():
temp = self.__read()
m = 'unexpected symbol "%s" at:' % temp
raise error.MyPLError(m, self.line, self.column)
checker = True
if self.__peek() == '.' and input.isdigit():
checker = False
#checking for operators
if checker == True:
if (input in noSpaceSymbols or self.__peek() in noSpaceSymbols) and input != "":
if input == '!' and self.__peek() != '=':
raise error.MyPLError("extra exclamation mark at ", self.line, self.column)
temp = input + self.__peek()
if len(input) == 1:
if temp != '!=' and temp != '==':
if input in comparisonsOp:
if self.__peek() in comparisonsOp == False:
keepLooping = False
else:
keepLooping = False
else:
keepLooping = False
#increment column count
self.column += 1
if intFloatOrString != 3:
#checks to see if the input is an int
if(input.isdigit()):
intFloatOrString = 1
#checks to see if it is a double
else:
soFarSoGood = True #bool that checks to see if there are any alphabetical characters
numberOfDots = 0 #keeps track of the dots
if len(input) > 1:
for i, x in enumerate(input):
if x == '.':
numberOfDots += 1
#float error where there is nothing after the
if i + 1 == len(input):
m = input + "missing digit in float value at "
raise error.MyPLError(m, self.line, self.column)
#float error where there is an invalid number after the dot
#pre dot invalid number checking is taken care of up above
elif input[i+1].isdigit() == False and soFarSoGood:
m = 'unexpected character "%s" at ' % (self.__peek())
raise error.MyPLError(m, self.line, self.column)
elif x.isdigit() == False:
soFarSoGood = False
if soFarSoGood and numberOfDots == 1:
intFloatOrString = 2
#end of the line
if self.__peek() == '\n':
self.line += 1
self.column = 1;
temp = self.__read()
#input was a int float or string
if intFloatOrString != 0:
if intFloatOrString == 1:
inputType = token.INTVAL
elif intFloatOrString == 2:
inputType = token.FLOATVAL
else:
inputType = token.STRINGVAL
#input was not a value except for maybe a bool
else:
if input == '=':
inputType = token.ASSIGN
elif input == ',':
inputType = token.COMMA
elif input == ':':
inputType = token.COLON
elif input == '/':
inputType = token.DIVIDE
elif input == '.':
inputType = token.DOT
elif input == '==':
inputType = token.EQUAL
elif input == '':
oldColumn -= 1
inputType = token.EOS
elif input == '>':
inputType = token.GREATER_THAN
elif input == '>=':
inputType = token.GREATER_THAN_EQUAL
elif input == '<':
inputType = token.LESS_THAN
elif input == '<=':
inputType = token.LESS_THAN_EQUAL
elif input == '!=':
inputType = token.NOT_EQUAL
elif input == '(':
inputType = token.LPAREN
elif input == ')':
inputType = token.RPAREN
elif input == '-':
inputType = token.MINUS
elif input == '%':
inputType = token.MODULO
elif input == '*':
inputType = token.MULTIPLY
elif input == '+':
inputType = token.PLUS
elif input == ';':
inputType = token.SEMICOLON
elif input == 'bool':
inputType = token.BOOLTYPE
elif input == 'int':
inputType = token.INTTYPE
elif input == 'float':
inputType = token.FLOATTYPE
elif input == 'string':
inputType = token.STRINGTYPE
elif input == 'struct':
inputType = token.STRUCTTYPE
elif input == 'and':
inputType = token.AND
elif input == 'or':
inputType = token.OR
elif input == 'not':
inputType = token.NOT
elif input == 'while':
inputType = token.WHILE
elif input == 'do':
inputType = token.DO
elif input == 'if':
inputType = token.IF
elif input == 'then':
inputType = token.THEN
elif input == 'else':
inputType = token.ELSE
elif input == 'elif':
inputType = token.ELIF
elif input == 'end':
inputType = token.END
elif input == 'fun':
inputType = token.FUN
elif input == 'var':
inputType = token.VAR
elif input == 'set':
inputType = token.SET
elif input == 'return':
inputType = token.RETURN
elif input == 'new':
inputType = token.NEW
elif input == 'false' or input == 'true':
inputType = token.BOOLVAL
elif input == 'nil':
inputType = token.NIL
else:
inputType = token.ID
newToken = token.Token(inputType, input, oldLine, oldColumn)
return newToken