'In Trino (Presto) SQL, how do you convert a varchar (string) to an array of characters (char)?

I want to create a array of characters from a varchar field. For example, from 'test', I want to have ARRAY['t', 'e', 's', 't'].

sql presto trino

Solution 1:^[1]

Here's one way:

SELECT REGEXP_EXTRACT_ALL('test?', '.') AS letters;

returns:

#	letters
1	["t","e","s","t","?"]

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Solution	Source
Solution 1	Will Fitzgerald