Is there any writef() format specifier for a bool?

Question

I looked at the writef() documentation for any bool specifier and there didn't seem to be any.

In a Chapel program I have: ...

config const verify = false;
/* that works but I want to use writef() to also print a bunch of other stuff*/
writeln("verify = " + verify); 
writef("verify = %<what-specifier-goes-here>\n", verify);

This last statement works ok.

// I guess I could do:

writef( "verify = %s\n",if verify then "true" else "false");

Answer 1

Based on the FormattedIO documentation, there is not a bool specifier available in Chapel's formatted IO.

Instead, you can use the generic specifier (%t) to print bool types in formatted IO:

config const verify = false;
writef("verify = %t\n", verify);

This specifier utilizes the writeThis or readWriteThis method of the type to print the variable. The Chapel IO documentation provides more details on how these methods work.