def __init__(self):
self.scanner = Scanner()
self.scanner.build()
class Cparser(object):
def __init__(self):
self.scanner = Scanner()
self.scanner.build()
tokens = Scanner.tokens
precedence = (
("nonassoc", 'IFX'),
("nonassoc", 'ELSE'),
("right", '='),
("left", 'OR'),
("left", 'AND'),
("left", '|'),
("left", '^'),
("left", '&'),
("nonassoc", '<', '>', 'EQ', 'NEQ', 'LE', 'GE'),
("left", 'SHL', 'SHR'),
("left", '+', '-'),
("left", '*', '/', '%'),
)
def p_error(self, p):
if p:
print("Syntax error at line {0}, column {1}: LexToken({2}, '{3}')"
.format(p.lineno, self.scanner.find_tok_column(p), p.type, p.value))
else:
print("Unexpected end of input")
def p_program(self, p):
"""program : components"""
p[0] = AST.Program(p[1])
def p_components(self, p):
"""components : components component
| """
p[0] = [] if len(p) == 1 else p[1] + [p[2]]
def p_component(self, p):
"""component : fundef
| instruction_component """
p[0] = p[1]
def p_instruction_component(self, p):
"""instruction_component : declaration
| instruction """
p[0] = p[1]
def p_declaration(self, p):
"""declaration : TYPE inits ';'
| error ';' """
p[0] = p[1] if len(p) == 3 else AST.Declaration(p[1], p[2])
def p_inits(self, p):
"""inits : inits ',' init
| init """
p[0] = p[1] + [p[3]] if len(p) == 4 else [p[1]]
def p_init(self, p):
"""init : ID '=' expression """
p[0] = AST.Initialisation(p[1], p[3], p.lineno(1))
def p_instructions(self, p):
"""instructions : instructions instruction
| instruction"""
p[0] = p[1] + [p[2]] if len(p) == 3 else [p[1]]
def p_instruction(self, p):
"""instruction : print_instr
| labeled_instr
| assignment
| choice_instr
| while_instr
| repeat_instr
| return_instr
| break_instr
| continue_instr
| compound_instr
| expression ';' """
p[0] = p[1]
def p_print_instr(self, p):
"""print_instr : PRINT expr_list ';'
| PRINT error ';' """
p[0] = AST.PrintInstruction(p[2])
def p_labeled_instr(self, p):
"""labeled_instr : ID ':' instruction """
p[0] = AST.LabeledInstruction(p[1], p[3], p.lineno(1))
def p_assignment(self, p):
"""assignment : ID '=' expression ';' """
p[0] = AST.Assignment(p[1], p[3], p.lineno(1))
def p_choice_instr(self, p):
"""choice_instr : IF '(' condition ')' instruction %prec IFX
| IF '(' condition ')' instruction ELSE instruction
| IF '(' error ')' instruction %prec IFX
| IF '(' error ')' instruction ELSE instruction """
p[0] = AST.ChoiceInstruction(*p[3::2])
def p_while_instr(self, p):
"""while_instr : WHILE '(' condition ')' instruction
| WHILE '(' error ')' instruction """
p[0] = AST.WhileInstruction(p[3], p[5])
def p_repeat_instr(self, p):
"""repeat_instr : REPEAT instructions UNTIL condition ';' """
p[0] = AST.RepeatInstruction(p[2], p[4])
def p_return_instr(self, p):
"""return_instr : RETURN expression ';' """
p[0] = AST.ReturnInstruction(p[2], p.lineno(1))
def p_continue_instr(self, p):
"""continue_instr : CONTINUE ';' """
p[0] = AST.ContinueInstruction(p.lineno(1))
def p_break_instr(self, p):
"""break_instr : BREAK ';' """
p[0] = AST.BreakInstruction(p.lineno(1))
def p_compound_instr(self, p):
"""compound_instr : '{' instruction_components '}' """
p[0] = AST.CompoundInstruction(p[2], p.lineno(3))
def p_intruction_components(self, p):
"""instruction_components : instruction_components instruction_component
| instruction_component"""
p[0] = [p[1]] if len(p) == 2 else p[1] + [p[2]]
def p_condition(self, p):
"""condition : expression"""
p[0] = p[1]
def p_const(self, p):
"""const : float
| integer
| string"""
p[0] = p[1]
def p_integer(self, p):
"""integer : INTEGER"""
p[0] = AST.Integer(p[1])
def p_float(self, p):
"""float : FLOAT"""
p[0] = AST.Float(p[1])
def p_string(self, p):
"""string : STRING"""
p[0] = AST.String(p[1])
def p_expression(self, p):
"""expression : const
| ID
| expression '+' expression
| expression '-' expression
| expression '*' expression
| expression '/' expression
| expression '%' expression
| expression '|' expression
| expression '&' expression
| expression '^' expression
| expression AND expression
| expression OR expression
| expression SHL expression
| expression SHR expression
| expression EQ expression
| expression NEQ expression
| expression '>' expression
| expression '<' expression
| expression LE expression
| expression GE expression
| '(' expression ')'
| '(' error ')'
| ID '(' expr_list_or_empty ')'
| ID '(' error ')' """
if len(p) == 5:
p[0] = AST.FunctionCall(p[1], p[3], p.lineno(1))
elif len(p) == 4 and p[1] == '(':
p[0] = p[2]
elif len(p) == 4:
p[0] = AST.BinExpr(p[2], p[1], p[3], p.lineno(2))
else:
p[0] = AST.JustID(p[1], p.lineno(1)) if type(p[1]) is str else p[1]
def p_expr_list_or_empty(self, p):
"""expr_list_or_empty : expr_list
| """
p[0] = [] if len(p) == 1 else p[1]
def p_expr_list(self, p):
"""expr_list : expr_list ',' expression
| expression """
p[0] = [p[1]] if len(p) == 2 else p[1] + [p[3]]
def p_fundef(self, p):
"""fundef : TYPE ID '(' args_list_or_empty ')' compound_instr """
p[0] = AST.FunctionDefinition(p[1], p[2], p[4], p[6], p.lineno(1))
def p_args_list_or_empty(self, p):
"""args_list_or_empty : args_list
| """
p[0] = [] if len(p) == 1 else p[1]
def p_args_list(self, p):
"""args_list : args_list ',' arg
| arg """
p[0] = [p[1]] if len(p) == 2 else p[1] + [p[3]]
def p_arg(self, p):
"""arg : TYPE ID """
p[0] = AST.FunctionArgument(p[1], p[2], p.lineno(1))
