xrpl-hooks-ide/xrpl-hooks-docs/md/hooks-guard-in-for.md

hooks-guard-in-for

Consider the following for-loop in C:

#define GUARD(maxiter) _g(__LINE__, (maxiter)+1)
for (int i = 0; GUARD(3), i < 3; ++i)

To satisfy the guard rule when using a for-loop in C guard should be placed either in the condition part of the loop, or as a first call in loop body, e.g.

for(int i = 0; i < 3; ++i) {
  GUARD(3);
}

In case of nested loops, the guard limit value should be multiplied by a number of iterations in each loop, e.g.

for(int i = 0; GUARD(3), i < 3; ++i) {
  for (int j = 0; GUARD(17), j < 5; ++j)
}

(most descendant loop iterations + 1) * (each parent loops iterations) - 1

This check will warn if the GUARD call is missing and also it will propose a GUARD value based on the for loop initial value, the increment and loop condition.

Read more