Question: I have a list of names like below

`100m LJ SP HJ 400m` 

I would like to have this in the following format:

`"100m", "LJ", "SP", "HJ", "400m"`

Is there any function that preexisted in R?

Answer: 
To override the value of a #define in Mbed OS, you can use the mbed\_app.json file in your project. This file allows you to specify configuration values for your application, including the ability to override #define values in the Mbed OS libraries.

To override the value of OS\_ISR\_FIFO\_QUEUE, you can add the following to your mbed\_app.json file:

```
{
    "target_overrides": {
        "*": {
            "OS_ISR_FIFO_QUEUE": 32
        }
    }
}

```

This will set the value of OS\_ISR\_FIFO\_QUEUE to 32 for all targets. You can also specify a target-specific value by replacing the "\*" with the name of the target you want to override the value for.

After you've added the configuration to your mbed\_app.json file, you can use the mbed config command to apply the configuration to your project. For example, you can use the following command to set the value of OS\_ISR\_FIFO\_QUEUE to 32:

`mbed config -c OS_ISR_FIFO_QUEUE=32`

This will update your mbed\_app.json file with the new value, and you can then build your project as usual. The new value of OS\_ISR\_FIFO\_QUEUE will be used when your application is built.

hope this helps for you!
Googling for the original source file I found that:

```
//   <o>ISR FIFO Queue 
//      <4=>  4 entries    <8=>   8 entries   <12=>  12 entries   <16=>  16 entries
//     <24=> 24 entries   <32=>  32 entries   <48=>  48 entries   <64=>  64 entries
//     <96=> 96 entries  <128=> 128 entries  <196=> 196 entries  <256=> 256 entries
//   <i> RTOS Functions called from ISR store requests to this buffer.
//   <i> Default: 16 entries
#ifndef OS_ISR_FIFO_QUEUE
#define OS_ISR_FIFO_QUEUE           16
#endif

```

The purpose of this file is to set the associated module's configuration. So you can go and modify it directly without any issue.

Now, if your concern is about not getting into the ifdef/if because this define already exists, then you can undefine it (although it might not be the proper way to go):

```
#ifdef OS_ISR_FIFO_QUEUE
#undef OS_ISR_FIFO_QUEUE
#endif

#ifndef OS_ISR_FIFO_QUEUE
#define OS_ISR_FIFO_QUEUE 1234 // your value
#endif

```

Indeed, if the define already exists, you should rather look for the place it is defined and modify the value there.