# string_Find
Look for the first occurence of `needle` in `haystack` and return its index in the string. If it isn't found, return -1.

## Arguments
- haystack (string): the string to search.
- needle (string): the substring to look for.

## Returns
index (int): the index of the first occurence of `needle` in `haystack`. If it isn't found, return -1.

## Example
### Ground
```python
call !string_Find "abcdefg" "d" &index
println $index # 3
```

### Solstice
```c
puts string_Find("abcdefg", "d") // 3
```