Based on ksh conventions; everything is split into words delimited by spaces
Expressions can have spaces embedded in them, causing ambiguous situations. For example, consider the following two commands:
when a -temp when a-temp
In the first example, even though the application might have a variable named temp, the dbx parser resolves the event specification in favor of-temp being a modifier. In the second example, a-temp is collectively passed to a language-specific expression parser. There must be variables named a and temp or an error occurs. Use parentheses to force parsing.