Relevant Discussion

#1805 (comment)

Describe the feature

Declare constant scalars with the fortran parameter keyword and use the fact that their value is known to treat indexing with a constant in the same way as indexing with a literal.

Test Code

Provide code which does not currently work but which should do when this issue is fixed:

def f(a : 'int[:]'):
     pad: 'const int' = 3
     b = a[pad:-pad]

Proposed Solution

A constant variable initialised with a Literal should be saved in a pyccel.ast.variable.Constant . Constants should be declared in the generated code as parameters. They should be handled in the same way as literals when handling indexing (i.e. avoiding unnecessary positivity checks.

_Originally suggested by @said-hadjout in #1805 (comment)