34     def check_expr(self, s):  member in RoundtripLegalSyntaxTestCase
99         self.check_expr("foo(1)")
100         self.check_expr("[1, 2, 3]")
101         self.check_expr("[x**3 for x in range(20)]")
102         self.check_expr("[x**3 for x in range(20) if x % 3]")
103         self.check_expr("[x**3 for x in range(20) if x % 2 if x % 3]")
104         self.check_expr("list(x**3 for x in range(20))")
105         self.check_expr("list(x**3 for x in range(20) if x % 3)")
106         self.check_expr("list(x**3 for x in range(20) if x % 2 if x % 3)")
107         self.check_expr("foo(*args)")
108         self.check_expr("foo(*args, **kw)")
109         self.check_expr("foo(**kw)")
110         self.check_expr("foo(key=value)")
111         self.check_expr("foo(key=value, *args)")
112         self.check_expr("foo(key=value, *args, **kw)")
113         self.check_expr("foo(key=value, **kw)")
114         self.check_expr("foo(a, b, c, *args)")
115         self.check_expr("foo(a, b, c, *args, **kw)")
116         self.check_expr("foo(a, b, c, **kw)")
117         self.check_expr("foo(a, *args, keyword=23)")
118         self.check_expr("foo + bar")
119         self.check_expr("foo - bar")
120         self.check_expr("foo * bar")
121         self.check_expr("foo / bar")
122         self.check_expr("foo // bar")
123         self.check_expr("(foo := 1)")
124         self.check_expr("lambda: 0")
125         self.check_expr("lambda x: 0")
126         self.check_expr("lambda *y: 0")
127         self.check_expr("lambda *y, **z: 0")
128         self.check_expr("lambda **z: 0")
129         self.check_expr("lambda x, y: 0")
130         self.check_expr("lambda foo=bar: 0")
131         self.check_expr("lambda foo=bar, spaz=nifty+spit: 0")
132         self.check_expr("lambda foo=bar, **z: 0")
133         self.check_expr("lambda foo=bar, blaz=blat+2, **z: 0")
134         self.check_expr("lambda foo=bar, blaz=blat+2, *y, **z: 0")
135         self.check_expr("lambda x, *y, **z: 0")
136         self.check_expr("(x for x in range(10))")
137         self.check_expr("foo(x for x in range(10))")
138         self.check_expr("...")
139         self.check_expr("a[...]")
452         self.check_expr('[]')
453         self.check_expr('[*{2}, 3, *[4]]')
456         self.check_expr('{*{2}, 3, *[4]}')
457         self.check_expr('{2}')
458         self.check_expr('{2,}')
459         self.check_expr('{2, 3}')
460         self.check_expr('{2, 3,}')
463         self.check_expr('{}')
464         self.check_expr('{a:b}')
465         self.check_expr('{a:b,}')
466         self.check_expr('{a:b, c:d}')
467         self.check_expr('{a:b, c:d,}')
468         self.check_expr('{**{}}')
469         self.check_expr('{**{}, 3:4, **{5:6, 7:8}}')
472         self.check_expr("f(*a, **b)")
473         self.check_expr('f(a, *b, *c, *d)')
474         self.check_expr('f(**a, **b)')
475         self.check_expr('f(2, *a, *b, **b, **c, **d)')
476         self.check_expr("f(*b, *() or () and (), **{} and {}, **() or {})")
479         self.check_expr('{x for x in seq}')
480         self.check_expr('{f(x) for x in seq}')
481         self.check_expr('{f(x) for x in seq if condition(x)}')
484         self.check_expr('{x:x for x in seq}')
485         self.check_expr('{x**2:x[3] for x in seq if condition(x)}')
486         self.check_expr('{x:x for x in seq1 for y in seq2 if condition(x, y)}')