What steps will reproduce the problem?
1. Try to evaluate "3**3**3" in the tutorial calculator parser in
https://bitbucket.org/vlasovskikh/funcparserlib/src/16ed98522a11620d10f5c3a9d363
82e2e0931c59/doc/Tutorial.md?at=0.3.x
2. Try to evaluate "3**3**3" in Python.
What is the expected output? What do you see instead?
3**3**3 should be 3**(3**3) == 7625597484987, but when treated as
left-associative, it is (3**3)**3 == 3**(3*3) == 3**9 == 19683
What version of the product are you using? On what operating system?
0.3.6
Please provide any additional information below.
The following code will make the ** operator right-associative.
def eval_expr_r(lst, z):
return reduce(lambda s, (x, f): f(x, s), reversed(lst), z)
eval_r = unarg(eval_expr_r)
factor = many(primary + pow) + primary >> eval_r
Or simply design the grammar like this:
@with_forward_decls
def factor():
return (
primary + pow + factor >> (lambda (x,f,y): f(x,y))
| primary
)
Original issue reported on code.google.com by wks1...@gmail.com on 19 Aug 2013 at 4:55
Original issue reported on code.google.com by
wks1...@gmail.com
on 19 Aug 2013 at 4:55