# Tests of parse errors. # This is a "chunked" file; each "---" line demarcates a new parser input. # # TODO(adonovan): lots more tests. x = 1 + 2 ### "got newline, want primary expression" --- _ = *x ### `got '\*', want primary` --- # trailing comma is ok def f(a, ): pass def f(*args, ): pass def f(**kwargs, ): pass --- # Parameters are validated later. def f(**kwargs, *args, *, b=1, a, **kwargs, *args, *, b=1, a): pass --- def f(a, *-b, c): # ### `got '-', want ','` pass --- def f(**kwargs, *args, b=1, a, **kwargs, *args, b=1, a): pass --- def pass(): ### "not an identifier" pass --- def f : ### `got ':', want '\('` --- # trailing comma is ok f(a, ) f(*args, ) f(**kwargs, ) --- f(a=1, *, b=2) ### `got ',', want primary` --- _ = {x:y for y in z} # ok _ = {x for y in z} ### `got for, want ':'` --- def f(): pass pass ### `unindent does not match any outer indentation level` --- def f(): pass --- # Blank line after pass => outdent. def f(): pass --- # No blank line after pass; EOF acts like a newline. def f(): pass --- # This is a well known parsing ambiguity in Python. # Python 2.7 accepts it but Python3 and Starlark reject it. _ = [x for x in lambda: True, lambda: False if x()] ### "got lambda, want primary" _ = [x for x in (lambda: True, lambda: False) if x()] # ok in all dialects --- # Starlark, following Python 3, allows an unparenthesized # tuple after 'in' only in a for statement but not in a comprehension. # (Python 2.7 allows both.) for x in 1, 2, 3: print(x) _ = [x for x in 1, 2, 3] ### `got ',', want ']', for, or if` --- # Unparenthesized tuple is not allowed as operand of 'if' in comprehension. _ = [a for b in c if 1, 2] ### `got ',', want ']', for, or if` --- # Lambda is ok though. _ = [a for b in c if lambda: d] # ok # But the body of such a lambda may not be a conditional: _ = [a for b in c if (lambda: d if e else f)] # ok _ = [a for b in c if lambda: d if e else f] ### "got else, want ']'" --- # A lambda is not allowed as the operand of a 'for' clause. _ = [a for b in lambda: c] ### `got lambda, want primary` --- # Comparison operations are not associative. _ = (0 == 1) == 2 # ok _ = 0 == (1 == 2) # ok _ = 0 == 1 == 2 ### "== does not associate with ==" --- _ = (0 <= i) < n # ok _ = 0 <= (i < n) # ok _ = 0 <= i < n ### "<= does not associate with <" --- _ = (a in b) not in c # ok _ = a in (b not in c) # ok _ = a in b not in c ### "in does not associate with not in" --- # shift/reduce ambiguity is reduced _ = [x for x in a if b else c] ### `got else, want ']', for, or if` --- [a for b in c else d] ### `got else, want ']', for, or if` --- _ = a + b not c ### "got identifier, want in" --- f(1+2 = 3) ### "keyword argument must have form name=expr" --- print(1, 2, 3 ### `got end of file, want '\)'` --- _ = a if b ### "conditional expression without else clause" --- load("") ### "load statement must import at least 1 symbol" --- load("", 1) ### `load operand must be "name" or localname="name" \(got int literal\)` --- load("a", "x") # ok --- load(1, 2) ### "first operand of load statement must be a string literal" --- load("a", x) ### `load operand must be "x" or x="originalname"` --- load("a", x2=x) ### `original name of loaded symbol must be quoted: x2="originalname"` --- # All of these parse. load("a", "x") load("a", "x", y2="y") load("a", x2="x", "y") # => positional-before-named arg check happens later (!) --- # 'load' is not an identifier load = 1 ### `got '=', want '\('` --- # 'load' is not an identifier f(load()) ### `got load, want primary` --- # 'load' is not an identifier def load(): ### `not an identifier` pass --- # 'load' is not an identifier def f(load): ### `not an identifier` pass --- # A load statement allows a trailing comma. load("module", "x",) --- x = 1 + 2 ### "got newline, want primary expression" --- def f(): pass # this used to cause a spurious indentation error --- print 1 2 ### `got int literal, want newline` --- # newlines are not allowed in raw string literals raw = r'a ### `unexpected newline in string` b' --- # The parser permits an unparenthesized tuple expression for the first index. x[1, 2:] # ok --- # But not if it has a trailing comma. x[1, 2,:] ### `got ':', want primary` --- # Trailing tuple commas are permitted only within parens; see b/28867036. (a, b,) = 1, 2 # ok c, d = 1, 2 # ok --- a, b, = 1, 2 ### `unparenthesized tuple with trailing comma` --- a, b = 1, 2, ### `unparenthesized tuple with trailing comma` --- # See github.com/google/starlark-go/issues/48 a = max(range(10))) ### `unexpected '\)'` --- # github.com/google/starlark-go/issues/85 s = "\x-0" ### `invalid escape sequence`