Returns a list of start and end positions where matches were encountered.
Example:
# Example for reg_filter
println reg_filter("hello","l") # [[2,3],[3,4]]
Does string contain a match for regular expression regex?
Example:
# Example for reg_match
println reg_match("abc123","\\d+") # true
Replaces matches found in var with regex to replacement.
Example:
# Example for reg_replace
println reg_replace("abc123","\\d+","X") # abcX