def parse_declaration(self) -> list:
# Int thing
# Int thing = expr
# TODO: module.Thingy thing
#
# "Int thing = expr" produces overlapping Declaration and
# Assignment nodes, that's why this returns a list of nodes
datatype = self.parse_name() # TODO: module's Thing
variable = self.parse_name()
if self.tokens.coming_up().kind == 'NEWLINE':
self.tokens.pop_newline()
return [
Declaration(Location.between(datatype, variable), datatype,
variable.name)
]
self.tokens.check_and_pop('OP', '=')
initial_value = self.parse_expression()
self.tokens.pop_newline()
return [
Declaration(Location.between(datatype, variable), datatype,
variable.name),
Assignment(Location.between(variable, initial_value), variable,
initial_value)
]
def test_parse_string():
assert get_ast('"hello"') == [ast.String(Location(0, 7), 'hello')]
# TODO: do something to escapes
assert get_ast(r'"hello \n\t"') == [
ast.String(Location(0, 12), r'hello \n\t')
]
def test_integers():
assert tokenize('1234') == [Token('INTEGER', '1234', Location(0, 4))]
# TODO: fix this
assert tokenize('0x1234') == [
Token('INTEGER', '0', Location(0, 1)),
Token('NAME', 'x1234', Location(1, 6)),
]
def test_names():
assert tokenize('hello') == [Token('NAME', 'hello', Location(0, 5))]
assert tokenize('lol123') == [Token('NAME', 'lol123', Location(0, 6))]
# i'm not sure if the tokenizer should raise an error about this,
# but this behaviour is ok for now
assert tokenize('123wolo') == [
Token('INTEGER', '123', Location(0, 3)),
Token('NAME', 'wolo', Location(3, 7)),
]
def test_trailing_commas(error_at):
assert get_ast('lol(1,)\n'
'lol(1, 2, 3,)') == [
ast.FunctionCall(Location(0, 7),
ast.Name(Location(0, 3), 'lol'),
[ast.Integer(Location(4, 5), '1')]),
ast.FunctionCall(Location(
0, 13, 2), ast.Name(Location(0, 3, 2), 'lol'), [
ast.Integer(Location(4, 5, 2), '1'),
ast.Integer(Location(7, 8, 2), '2'),
ast.Integer(Location(10, 11, 2), '3')
]),
]
with error_at(4, 5, msg="don't put a ',' here"):
get_ast('lol(,)')
with error_at(4, 5, msg="don't put a ',' here"):
get_ast('lol(,,)')
with error_at(13, 15, msg="two ',' characters"):
get_ast('lol(something,,)')
# this doesn't matter much because it's unlikely that anyone will
# accidentally put 3 commas next to each other
with error_at(13, 15, msg="two ',' characters"):
get_ast('lol(something,,,)')
def test_function_calls():
assert get_ast('lol()\n'
'lol(1)\n'
'lol(1, 2, 3)\n') == [
ast.FunctionCall(Location(0, 5),
ast.Name(Location(0, 3), 'lol'), []),
ast.FunctionCall(Location(0, 6, 2),
ast.Name(Location(0, 3, 2), 'lol'),
[ast.Integer(Location(4, 5, 2), '1')]),
ast.FunctionCall(Location(
0, 12, 3), ast.Name(Location(0, 3, 3), 'lol'), [
ast.Integer(Location(4, 5, 3), '1'),
ast.Integer(Location(7, 8, 3), '2'),
ast.Integer(Location(10, 11, 3), '3')
]),
]
def _parse_comma_list(self, start='(', stop=')', parsemethod=None):
# ( )
# ( element )
# ( element , )
# ( element , element )
# ( element , element , )
# ...
if parsemethod is None:
parsemethod = self.parse_expression
start_token = self.tokens.check_and_pop('OP', start)
if self.tokens.coming_up().startswith(['OP', stop]):
# empty list
return ([], self.tokens.pop())
elements = []
while True:
if self.tokens.coming_up().startswith(['OP', ',']):
raise CompileError("don't put a ',' here",
self.tokens.coming_up().location)
elements.append(parsemethod())
if self.tokens.coming_up().startswith(['OP', stop]):
return (elements, self.tokens.pop())
comma = self.tokens.check_and_pop('OP', ',')
if self.tokens.coming_up().startswith(['OP', ',']):
raise CompileError(
"two ',' characters",
Location.between(comma, self.tokens.coming_up()))
if self.tokens.coming_up().startswith(['OP', stop]):
return (elements, self.tokens.pop())
def parse_expression(self):
coming_up = self.tokens.coming_up()
if coming_up.kind == 'NAME':
# hello
result = self.parse_name()
elif coming_up.kind == 'STRING':
# "hello"
result = self.parse_string()
elif coming_up.kind == 'INTEGER':
# 123
result = self.parse_integer()
elif coming_up.startswith(['OP', '(']):
result = self.parse_parentheses()
else:
raise CompileError(
"this should be variable name, string, integer or '('",
coming_up.location)
# check for function calls, this is a while loop to allow
# function calls like thing()()()
while self.tokens.coming_up().startswith(['OP', '(']):
args, stop_token = self._parse_comma_list('(', ')')
result = FunctionCall(Location.between(result, stop_token), result,
args)
return result
def parse_function_def(self):
# function main() { ... }
# function thing() returns Int { ... }
function_keyword = self.tokens.check_and_pop('NAME', 'function')
name = self.parse_name()
args, junk = self._parse_comma_list('(',
')',
parsemethod=self._type_and_name)
if self.tokens.coming_up().startswith(['NAME', 'returns']):
self.tokens.pop()
returntype = self.parse_name()
else:
returntype = None
opening_brace = self.tokens.check_and_pop('OP', '{')
if self.tokens.coming_up().kind == 'NEWLINE':
self.tokens.pop_newline()
body = []
while not self.tokens.coming_up().startswith(['OP', '}']):
body.extend(self.parse_statement())
closing_brace = self.tokens.check_and_pop('OP', '}')
self.tokens.pop_newline()
return FunctionDef(Location.between(function_keyword, closing_brace),
name.name, args, returntype, body)
def test_parse_name(fake_keyword, error_at):
assert get_ast('hello') == [ast.Name(Location(0, 5), 'hello')]
with error_at(0,
4,
msg=("fake is not a valid variable name "
"because it has a special meaning")):
get_ast('fake')
def assignment(self):
# thing = value
# TODO: thing's stuff = value
target = self.parse_name()
self.tokens.check_and_pop('OP', '=')
value = self.parse_expression()
self.tokens.pop_newline()
return Assignment(Location.between(target, value), target, value)
def test_declaration_and_assignment():
assert get_ast('Int i') == [
ast.Declaration(Location(0, 5), ast.Name(Location(0, 3), 'Int'), 'i'),
]
assert get_ast('Int i = 123') == [
# these overlap
ast.Declaration(
Location(0, 5), # Int i
ast.Name(Location(0, 3), 'Int'),
'i'),
ast.Assignment(
Location(4, 11), # i = 123
ast.Name(Location(4, 5), 'i'),
ast.Integer(Location(8, 11), '123')),
]
assert get_ast('i = 123') == [
ast.Assignment(Location(0, 7), ast.Name(Location(0, 1), 'i'),
ast.Integer(Location(4, 7), '123')),
]
def parse_if(self):
# if cond { statements }
the_if = self.tokens.check_and_pop('NAME', 'if')
condition = self.parse_expression()
self.tokens.check_and_pop('OP', '{')
body = []
# allow "if thing { }" without a newline
if not self.tokens.coming_up().startswith(['OP', '}']):
self.tokens.pop_newline()
while not self.tokens.coming_up().startswith(['OP', '}']):
body.extend(self.parse_statement())
closing_brace = self.tokens.check_and_pop('OP', '}')
self.tokens.pop_newline()
return If(Location.between(the_if, closing_brace), condition, body)
def parse_file(self):
while True:
try:
self.tokens.coming_up(1)
except EOFError:
break
try:
yield from self.parse_statement()
except EOFError:
# underline 3 blanks after last token
last_location = self.tokens.last_popped.location
mark_here = Location(last_location.end, last_location.end + 3,
last_location.lineno)
# python abbreviates this as EOF and beginners don't
# understand it, but i guess this one is good enough
raise CompileError("unexpected end of file", mark_here)
def test_if():
assert get_ast('if thing { }') == [
ast.If(Location(0, 12), ast.Name(Location(3, 8), 'thing'), []),
]
assert get_ast('if thing {\n'
'\tstuff\n'
'\tmore_stuff\n'
'}') == [
ast.If(
Location(0,
None), # None because it's not a 1-liner
ast.Name(Location(3, 8), 'thing'),
[
ast.Name(Location(4, 9, 2), 'stuff'),
ast.Name(Location(4, 14, 3), 'more_stuff')
])
]
def test_parse_integer():
assert get_ast('123') == [ast.Integer(Location(0, 3), '123')]
def test_strings():
assert tokenize('"hello world"') == [
Token('STRING', '"hello world"', Location(0, 13))
]
with pytest.raises(CompileError):
tokenize('"hello \n world"')
def parse_return(self):
the_return = self.tokens.check_and_pop('NAME', 'return')
value = self.parse_expression()
self.tokens.pop_newline()
return Return(Location.between(the_return, value), value)
def test_whitespace():
assert tokenize(' \n \t \r ') == []
assert tokenize(' \n \t 123 \r ') == [
Token('INTEGER', '123', Location(5, 8, 2)),
]
def test_comments():
assert tokenize('// hello\n123') == [
Token('NEWLINE', '\n', Location(8, 11, 1)),
Token('INTEGER', '123', Location(0, 3, 2)),
]
assert tokenize('/* hello\nhello\nhello */') == []
def test_hello_world():
assert tokenize(_HELLO_WORLD) == [
Token('NEWLINE', '\n', Location(37, 40, 2)),
Token('NAME', 'import', Location(0, 6, 3)),
Token('NAME', 'stdout', Location(7, 13, 3)),
Token('NAME', 'from', Location(14, 18, 3)),
Token('STRING', '"io.weird"', Location(19, 29, 3)),
Token('NEWLINE', '\n', Location(29, 32, 3)),
Token('NEWLINE', '\n', Location(0, 3, 4)),
Token('NAME', 'function', Location(0, 8, 5)),
Token('NAME', 'main', Location(9, 13, 5)),
Token('OP', '(', Location(13, 14, 5)),
Token('OP', ')', Location(14, 15, 5)),
Token('OP', '{', Location(16, 17, 5)),
Token('NEWLINE', '\n', Location(17, 20, 5)),
Token('NAME', 'stdout', Location(4, 10, 6)),
Token('OP', '.', Location(10, 11, 6)),
Token('NAME', 'print', Location(11, 16, 6)),
Token('OP', '(', Location(16, 17, 6)),
Token('STRING', '"Hello World!"', Location(17, 31, 6)),
Token('OP', ')', Location(31, 32, 6)),
Token('NEWLINE', '\n', Location(32, 35, 6)),
Token('OP', '}', Location(0, 1, 7)),
Token('NEWLINE', '\n', Location(1, 4, 7)),
]
def test_function_returns_function():
assert get_ast('lol()()()') == [
ast.FunctionCall(
Location(0, 9),
ast.FunctionCall(
Location(0, 7),
ast.FunctionCall(Location(0, 5),
ast.Name(Location(0, 3), 'lol'), []), []),
[]),
]
assert get_ast('lol(1, 2)(3, 4)') == [
ast.FunctionCall(
Location(0, 15),
ast.FunctionCall(Location(0, 9), ast.Name(Location(0, 3), 'lol'), [
ast.Integer(Location(4, 5), '1'),
ast.Integer(Location(7, 8), '2')
]), [
ast.Integer(Location(10, 11), '3'),
ast.Integer(Location(13, 14), '4')
]),
]
def test_return():
assert get_ast('return 123') == [
ast.Return(Location(0, 10), ast.Integer(Location(7, 10), '123')),
]
def test_function_defs():
assert get_ast(
'function thing() {\n'
'\tlol()\n'
'\tlol()\n'
'}') == [
ast.FunctionDef(
Location(0, None),
'thing', # function name
[], # arguments
None, # return type
[ # body
ast.FunctionCall(Location(4, 9, 2),
ast.Name(Location(4, 7, 2), 'lol'), []),
ast.FunctionCall(Location(4, 9, 3),
ast.Name(Location(4, 7, 3), 'lol'), []),
]),
]
# 0-statement 1-liner
assert get_ast('function thing(Int i, String s) returns String { }') == [
ast.FunctionDef(
Location(0, 50),
'thing',
# arguments are (type, name) tuples
[(ast.Name(Location(15, 18), 'Int'), ast.Name(
Location(19, 20), 'i')),
(ast.Name(Location(22, 28),
'String'), ast.Name(Location(29, 30), 's'))],
ast.Name(Location(40, 46), 'String'),
[]),
]
def test_parentheses():
# FIXME: currently the whole expression starts at column 4 and
# that's not quite right...
assert get_ast('(((("hello"))))') == [ast.String(Location(4, 11), 'hello')]
def test_ops(error_at):
for op in '= ( ) { } [ ] , .'.split():
assert tokenize(op) == [Token('OP', op, Location(0, len(op)))]
with error_at(0, 1, msg="I don't know what this is"):
tokenize(';')