def test_eval_assignment():
ctx = Context()
# Do not allow assigning to non-trivial expressions
ast, _ = exp.parse('(1+1*x)*9')
with raises(Exception):
ast.value = 10
# Do not allow assigning to built-in constants
ast, _ = exp.parse('True')
with raises(Exception):
ast.value = 10
# Do not allow assigning to function calls
ast, _ = exp.parse('f(1)')
with raises(Exception):
ast.value = 10
# Do not allow assigning to constant lists
ast, _ = exp.parse("[1,2,3,4]")
with raises(Exception):
ast.value = 10
# Do not allow assigning to constants
ast, _ = exp.parse("'ahoj'")
with raises(Exception):
ast.value = 10
# Allow assigning to non-existing variables
ast, _ = exp.parse('x')
ast.bind_ctx(ctx)
ast.value = 10
assert ctx.x == 10
# Allow assigning to existing variables
ast.value = 20
assert ctx.x == 20
# Allow assigning to list elements
ctx.lst = [1, 2, 3]
ctx.x = 0
ast, _ = exp.parse("lst[x]")
ast.bind_ctx(ctx)
ast.value = 20
assert ctx.lst[0] == 20
# Allow assigning to non-existing object attributes
ctx.obj = Context()
ast, _ = exp.parse('obj.test')
ast.bind_ctx(ctx)
ast.value = 30987
assert ctx.obj.test == 30987
# Allow assigning to existing object attributes
ast.value = 40
assert ctx.obj.test == 40
def test_parse():
ctx = Context()
# Test Simple Arithmetic Expressions
ast, _ = exp.parse('(1+1*8)*9')
assert ast.evalctx(ctx) is 81
# Test Simple Arithmetic Expressions
ast, _ = exp.parse('(1-1)')
assert ast.evalctx(ctx) is 0
# Test Simple Arithmetic Expressions
ast, _ = exp.parse('(-1)')
assert ast.evalctx(ctx) is -1
# Test Boolean Expressions
ast, _ = exp.parse('True and False')
assert ast.evalctx(ctx) is False
ast, _ = exp.parse('True and not False')
assert ast.evalctx(ctx) is True
# Test is
ast, _ = exp.parse("1 is None")
assert ast.evalctx(ctx) is False
ast, _ = exp.parse("None is None")
assert ast.evalctx(ctx) is True
ast, _ = exp.parse("False is not None")
assert ast.evalctx(ctx) is True
# Test Slices
ctx.s = "abcde"
ast, _ = exp.parse('s[-1]')
assert ast.evalctx(ctx) == 'e'
ast, _ = exp.parse('s[0]')
assert ast.evalctx(ctx) == 'a'
ast, _ = exp.parse('s[1:3]')
assert ast.evalctx(ctx) == 'bc'
ast, _ = exp.parse('s[0:-1:2]')
assert ast.evalctx(ctx) == 'ac'
ast, _ = exp.parse('s[1:]')
assert ast.evalctx(ctx) == 'bcde'
ast, _ = exp.parse('s[:-1]')
assert ast.evalctx(ctx) == 'abcd'
# Test Lists
ast, _ = exp.parse('[1,2,3,4]')
assert ast.evalctx(ctx) == [1, 2, 3, 4]
# Test Comprehension
ast, _ = exp.parse('[p+1 for p in [1,2,3,4]]')
assert ast.evalctx(ctx) == [2, 3, 4, 5]
ast, _ = exp.parse('[p+1 for p in [1,2,3,4] if p%2==0]')
assert ast.evalctx(ctx) == [3, 5]
# Test Builtins
ast, _ = exp.parse("str(10)")
assert ast.evalctx(ctx) == "10"
ast, _ = exp.parse("int('21')")
assert ast.evalctx(ctx) == 21
ast, _ = exp.parse("len([1,2,3])")
assert ast.evalctx(ctx) == 3
ctx.str = lambda x: "str(" + str(x) + ")"
ast, _ = exp.parse("str(10)")
assert str(ast) == "str(10)"
del ctx.str
# Test Object Access
ctx.obj = Context()
ctx.obj.a = 10
ctx.obj.b = Context()
ctx.obj.b.c = 20
ctx.obj.d = [Context({'a': 30})]
ast, _ = exp.parse('obj.a')
assert ast.evalctx(ctx) == 10
ast, _ = exp.parse('obj.b.c')
assert ast.evalctx(ctx) == 20
ast, _ = exp.parse('obj.d[0].a')
assert ast.evalctx(ctx) == 30
# Test Array Access
ast, _ = exp.parse('mylst[0][1][2]')
ctx.mylst = [[None, [None, None, "Ahoj"]]]
assert ast.evalctx(ctx) == "Ahoj"
# Test String slices
ast, _ = exp.parse('"ahoj"[1:]')
assert ast.evalctx(ctx) == "hoj"
ast, _ = exp.parse('"ahoj"[:1]')
assert ast.evalctx(ctx) == "a"
ast, _ = exp.parse('"ahoj"[-1]')
assert ast.evalctx(ctx) == "j"
# Test array concatenation
ast, _ = exp.parse('([0]+["mixin"])[1]')
assert ast.evalctx(ctx) == "mixin"
# Test Function Calls
ast, _ = exp.parse('"a,b,c,d".split(",")')
assert ast.evalctx(ctx) == ['a', 'b', 'c', 'd']
ctx.func = lambda x, ev: str(x + 10) + ev
ctx.ch = 20
ctx.s = 'Hi'
ast, _ = exp.parse("func(ch,ev=s)")
ast.bind_ctx(ctx)
ctx.s = 'Hello'
assert ast.eval() == '30Hello'
assert ast.evalctx(ctx) == '30Hello'
# Test Complex Expressions
expr = '(1+2*obj.a - 10)'
ast, _ = exp.parse(expr)
assert ast.evalctx(ctx) == 11
expr = '[(1+2*a[1+3] - 10) for a in [[2,1,2,3,4,5],[1,2],[2,2,2,2,2,2,2]] if a[0] % 2 == 0]'
ast, _ = exp.parse(expr)
assert ast.evalctx(ctx) == [-1, -5]
# Test parse cache
for i in range(10):
expr = '[(1+2*a[1+3] - 10) for a in [[2,1,2,3,4,5],[1,2],[2,2,2,2,2,2,2]] if a[0] % 2 == 0]'
ast, _ = exp.parse(expr)
assert ast.evalctx(ctx) == [-1, -5]