def help_eval(self, s):
l = lexer.Lexer(s)
p = parser.Parser(l)
program = p.parse_program()
env = {}
funcs = {}
try:
return evaluator.eval(program, env, funcs)
except evaluator.EvaluatedError:
print(env)
pass
def test_return_statement(self):
input = "return 5; return a; return a * b;"
l = lexer.Lexer(input)
p = parser.Parser(l)
program = p.parse_program()
self.check_parser_errors(p)
self.assertEqual(type(program), ast.Program)
self.assertEqual(len(program.statements), 3)
for stmt in program.statements:
self.assertEqual(type(stmt), ast.ReturnStatement)
self.assertEqual(stmt.token_literal(), "return")
def test_prefix_expression(self):
input = "-5;"
l = lexer.Lexer(input)
p = parser.Parser(l)
program = p.parse_program()
self.check_parser_errors(p)
self.assertEqual(len(program.statements), 1)
self.assertEqual(type(program.statements[0]), ast.ExpressionStatement)
self.assertEqual(type(program.statements[0].expression),
ast.PrefixExpression)
prefix = program.statements[0].expression
self.help_test_integer_literal(prefix.right, 5)
self.assertEqual(prefix.operator, "-")
def test_integer_literal_expression(self):
input = "5;"
l = lexer.Lexer(input)
p = parser.Parser(l)
program = p.parse_program()
self.check_parser_errors(p)
self.assertEqual(len(program.statements), 1)
self.assertEqual(type(program.statements[0]), ast.ExpressionStatement)
self.assertEqual(type(program.statements[0].expression),
ast.IntegerLiteral)
ident = program.statements[0].expression
self.assertEqual(ident.value, 5)
self.assertEqual(ident.token_literal(), "5")
def test_return_completion(self):
tests = [["return a * b * 3;", ast.InfixExpression],
["return add(3);", ast.CallExpression]]
for tt in tests:
l = lexer.Lexer(tt[0])
p = parser.Parser(l)
program = p.parse_program()
self.check_parser_errors(p)
self.assertEqual(len(program.statements), 1)
self.assertEqual(type(program.statements[0]), ast.ReturnStatement)
stmt = program.statements[0]
exp = stmt.return_value
self.assertEqual(type(exp), tt[1])
def test_function_define(self):
tests = [["def a(abc, abc, def) {a + b + c;}", 3],
["def abcde() { return a + b; }", 0]]
for i, tt in enumerate(tests):
l = lexer.Lexer(tt[0])
p = parser.Parser(l)
program = p.parse_program()
self.check_parser_errors(p)
self.assertEqual(len(program.statements), 1)
stmt = program.statements[0]
self.assertEqual(type(stmt), ast.FunctionStatement)
self.assertEqual(type(stmt.id), ast.Identifier)
self.assertEqual(type(stmt.block), ast.BlockStatement)
self.help_test_function(stmt, tt[1])
def test_operator_precedence(self):
tests = [["-a * b", "((-a) * b)"], ["a + b + c", "((a + b) + c)"],
["-a - b - c", "(((-a) - b) - c)"],
["a / b / c", "((a / b) / c)"],
[" a + b * c / d - e", "((a + ((b * c) / d)) - e)"]]
for tt in tests:
l = lexer.Lexer(tt[0])
p = parser.Parser(l)
program = p.parse_program()
self.check_parser_errors(p)
self.assertEqual(len(program.statements), 1)
self.assertEqual(type(program.statements[0]),
ast.ExpressionStatement)
self.assertEqual(str(program.statements[0]), tt[1])
def file_main(f):
res = None
env = {}
funcs = {}
lex = lexer.Lexer(f.read())
par = parser.Parser(lex)
program = par.parse_program()
if len(par.errors) != 0:
for msg in par.errors:
print(msg, file=sys.stderr)
try:
res = evaluator.eval(program, env, funcs)
print(res.inspect())
except evaluator.EvaluatedError as e:
print(e.msg, file=sys.stderr)
def test_assign_statement(self):
input = "a = 5; b = 5; c = 10;"
l = lexer.Lexer(input)
p = parser.Parser(l)
program = p.parse_program()
self.check_parser_errors(p)
self.assertEqual(type(program), ast.Program)
self.assertEqual(len(program.statements), 3)
tests = [
"a",
"b",
"c",
]
for i, tt in enumerate(tests):
stmt = program.statements[i]
self.help_test_assign_statement(stmt, tt[0], i)
def parser_main():
print("Let's go!!!")
print(PROMPT, end='')
line = input()
while line != "":
lex = lexer.Lexer(line)
par = parser.Parser(lex)
program = par.parse_program()
if len(par.errors) != 0:
for msg in par.errors:
print(msg)
print(PROMPT, end='')
line = input()
continue
print(str(program))
print(PROMPT, end='')
line = input()
def test_infix_expression(self):
tests = [["7 + 5;", 7, "+", 5], ["7 - 5;", 7, "-", 5],
["7 * 5;", 7, "*", 5], ["7 / 5;", 7, "/", 5]]
for tt in tests:
l = lexer.Lexer(tt[0])
p = parser.Parser(l)
program = p.parse_program()
self.check_parser_errors(p)
self.assertEqual(len(program.statements), 1)
self.assertEqual(type(program.statements[0]),
ast.ExpressionStatement)
self.assertEqual(type(program.statements[0].expression),
ast.InfixExpression)
infix = program.statements[0].expression
self.assertEqual(infix.operator, tt[2])
self.help_test_integer_literal(infix.right, tt[3])
self.help_test_integer_literal(infix.left, tt[1])
def test_call_expression(self):
tests = [["add(1, 2, 3);", 3], ["add(1+2, 2/3);", 2]]
for tt in tests:
l = lexer.Lexer(tt[0])
p = parser.Parser(l)
program = p.parse_program()
self.check_parser_errors(p)
self.assertEqual(len(program.statements), 1)
self.assertEqual(type(program.statements[0]),
ast.ExpressionStatement)
stmt = program.statements[0]
exp = stmt.expression
self.assertEqual(type(exp), ast.CallExpression)
self.assertEqual(type(exp.function), ast.Identifier)
self.assertEqual(len(exp.arguments), tt[1])
if tt[1] != 0:
self.assertTrue(
isinstance(exp.arguments[0], ast.ExpressionNode))
def eval_main():
print("Let's go!!!")
print(PROMPT, end='')
line = input()
env = {}
funcs = {}
while line != "":
lex = lexer.Lexer(line)
par = parser.Parser(lex)
program = par.parse_program()
if len(par.errors) != 0:
for msg in par.errors:
print(msg)
print(PROMPT, end='')
line = input()
continue
try:
res = evaluator.eval(program, env, funcs)
print(res.inspect())
except evaluator.EvaluatedError as e:
print(e.msg)
print(PROMPT, end='')
line = input()
