CharacterFormat fails to take values

Question

I'm finding that CharacterFormat (soon ITextLayoutFormat)
fails to take a value of "regular" for fontStyle. This code
illustrates the case (attached)
On the first run the traces are as expected, setting the text
to italic:
"existing fontWeight: normal"
"existing fontStyle: regular"
"new fontStyle: italic"
"should be: italic"
But when I click my italic button again it fails to reset the
text to regular because the "italic" CharacterFormat will not take
a value of FontStyle.REGULAR when using a conditional assignment
(ternary or if-else), the final trace shows the outcome of this
conditional assignment, it just never actually gets assigned (it
remains null). So the traces for when the text is already italic
are:
"existing fontWeight: normal"
"existing fontStyle: italic"
"new fontStyle: null"
"should be: regular"
I'm not using bold here so there's nothing running through
the BOLD_ITALIC stuff.

Answer 1

I guess this is where I should:
a) read the docs in minute detail
b) not rely on naming conventions when string assignment is
involved
The problem was fontStyle does not take a string found in
FontStyle, it takes a string in FontPosture, so "luckily"
FontStyle.ITALIC married up with the string for FontPosture.ITALIC,
but of course FontStyle.REGULAR was not suitable in place of the
FontPosture.NORMAL string.
It's a shame we don't have real enums because this naming
convention really threw me where other properties like fontWeight
do use a class that matches name-wise (FontWeight). I imagine this
won't be such a problem when the ASDoc hints the class types
instead of just String.