1. The aqua command parameter parser tokenizes key/value properties in a specific way:
<key>=["]<value>["], - note the quoting value is optional, key/value is separated by comma
2. After the tokenizer picks out the <value>, it does a "trim" on the value (which removes leading and trailing whitespace characters)
3. Due to 1 and 2 above, the following are invalid "Delimiter" syntax:
Delimiter=,, - because comma is a key/value separator
Delimiter=" ", - the value will be an empty string because whitespaces are trimmed
Delimiter= , - the value will be an empty string because whitespaces are trimmed
4. Therefore, in order to pass tab and space as delimiter values, the special tokens "{tab}" or "{space}" is used, and there is an additional step to replace "{tab}" to the tab character and "{space}" to the space character during actual execution of the command. That is,
Delimiter={tab}, or Delimiter="{tab}",
Delimiter={space}, or Delimiter="{space}",
5. So in the fix, I have added quotes around the delimiter value (so that comma, "," will work). However, I have preserved the use of "{tab}" and "{space}" (even though intuitively these tokens don't seem necessary because they could be quoted) so that we don't break existing scripts.
In summary, the following are correct delimiter syntax, and should be generated (and expected to work) in the Preview Script tab:
Delimiter="\"",
Delimiter=",",
Delimiter="{tab}",
Delimiter={space},
Delimiter="|", - an example of user-input value
