write a c macro that takes an array, it's length, and buffer string, and fill buffer with string representation of array. 
usage example:
```c
int main() {
    int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    char NAME_1[100];
    printf("%s\n", repr(a, 10, NAME_1)); // prints [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] 
    return 0;
}
``` Write your response with exactly 6 paragraphs, separated with the markdown divider: ***.
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