def main(argv):
"""Parse and run any Tiger program"""
# check for arguments
try:
file = argv[1]
except IndexError:
print(
"Expected one file name argument to be passed, e.g. ./tiger-interpreter program.tig"
)
return 40
program_contents = read_file(argv[1])
# set up environment
environment = create_empty_environment()
# parse input program
try:
program = Parser(program_contents,
argv[1]).parse(create_native_functions())
except ParseError as e:
print("Parse failure: %s" % e.to_string())
return 42
# evaluate the program
result = program.evaluate(environment)
# print the result and exit
if result:
print(result.to_string())
return 0
def test():
create_environment_with_natives()
program = Parser("let var a := 0 in (for i := 1 to 9 do a := a - i; a) end").parse()
environment = SimpleEnvironment()
result = program.evaluate(environment)
assert isinstance(result, IntegerValue)
return result.integer
def test():
program = Parser("""
let
var max : int := 50
var s : int := 0
var n : int := 2
in
while n <= max do
let
var p : int := 1
var d : int := 2
in
while d <= (n - 1) do
let
var m : int := d * (n / d)
in
if n <= m then
p := 0;
d := d + 1
end;
if p <> 0 then
s := s + n;
n := n + 1
end;
s
end
""").parse()
environment = create_environment_with_natives(
) # apparently RPython barfs if we just use Environment() here because NativeFunctionDeclaration.__init__ is never called so the flowspace does not know about the 'function' field
result = program.evaluate(environment)
assert isinstance(result, IntegerValue)
return result.integer
def test():
program = Parser(
'let var a := 0 in (while a < 100 do a := a + 1; a) end'
).parse(create_native_functions())
environment = create_environment_with_natives(
) # apparently RPython barfs if we just use Environment() here because NativeFunctionDeclaration.__init__ is never called so the flowspace does not know about the 'function' field
result = program.evaluate(environment)
assert isinstance(result, IntegerValue)
return result.integer
def evaluate(self, program, *existing_declarations):
existing_declarations_ast = [Parser(decl).parse() if isinstance(decl, str) else decl for decl in
existing_declarations]
if not existing_declarations_ast:
# ensure we have at least one existing declaration or the parser will not run the lvalue-transformation pass
existing_declarations_ast.append(NativeNoArgumentFunctionDeclaration('unused', None, lambda: None))
assert all(isinstance(a, Program) for a in existing_declarations_ast)
assert isinstance(program, str)
program_ast = Parser(program).parse(existing_declarations_ast)
return program_ast.evaluate(Environment.empty())
