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UnguardedIt

rascal-0.40.17

Synopsis​

The special variable it occurs outside a reducer expression.

Description​

A reducer is used to reduce all elements in a collection to a sngle value. The special variable it represents the currently reduced value and can be modified inside the reducer. This error is generated when it i used otuside the a reducer.

Remedies:

  • You have accidentially used a variable with the name it; rename your variable to something else.
  • Place the expression that contains it in a reducer expression.

Examples​

This is correct way to add all elements in a list:

rascal>(0 | it + n | int n <- [1,5,9] )
int: 15

Using it outside a reducer gives an error:

rascal>it + 3
|prompt:///|(0,2,<1,0>,<1,2>): Use of 'it' special variable is only allowed within reducers
Advice: |https://www.rascal-mpl.org/docs/Rascal/Errors/CompileTimeErrors/UnguardedIt|
ok