A delimiter definition is four strings (prefix, open, close, suffix)
that are concatenated with the character or string data to form an
operand. A delimiter set is a collection of delimiter definitions,
with separate entries for each character encoding.
This is a convenient way to configure Formatter objects, import and
export data from the app settings file, and manage the UI needed to
allow the user to customize how things look.
The full set of options didn't fit on the first app settings tab, so
there's now a separate tab just for specifying character and string
delimiters. (This might be overkill, but there are various plausible
scenarios that make use of it.)
The delimiters for on-screen display of strings can now be
configured.
The previous functions just grabbed 62 characters and slapped quotes
on the ends, but that doesn't work if we want to show strings with
embedded control characters. This change replaces the simple
formatter with the one used to generate assembly source code. This
increases the cost of refreshing the display list, so a cache will
need to be added in a future change.
Converters for C64 PETSCII and C64 Screen Code have been defined.
The results of changing the auto-scan encoding can now be viewed.
The string operand formatter was using a single delimiter, but for
the on-screen version we want open-quote and close-quote, and might
want to identify some encodings with a prefix. The formatter now
takes a class that defines the various parts. (It might be worth
replacing the delimiter patterns recently added for single-character
operands with this, so we don't have two mechanisms for very nearly
the same thing.)
While working on this change I remembered why there were two kinds
of "reverse" in the old Merlin 32 string operand generator: what you
want for assembly code is different from what you want on screen.
The ReverseMode enum has been resurrected.
The previous code output a character in single-quotes if it was
standard ASCII, double-quotes if high ASCII, or hex if it was neither
of those. If a flag was set, high ASCII would also be output as
hex.
The new system takes the character value and an encoding identifier.
The identifier selects the character converter and delimiter
pattern, and puts the two together to generate the operand.
While doing this I realized that I could trivially support high
ASCII character arguments in all assemblers by setting the delimiter
pattern to "'#' | $80".
In FormatDescriptor, I had previously renamed the "Ascii" sub-type
"LowAscii" so it wouldn't be confused, but I dislike filling the
project file with "LowAscii" when "Ascii" is more accurate and less
confusing. So I switched it back, and we now check the project
file version number when deciding what to do with an ASCII item.
The CharEncoding tests/converters were also renamed.
Moved the default delimiter patterns to the string table.
Widened the delimiter pattern input fields slightly. Added a read-
only TextBox with assorted non-typewriter quotes and things so
people have something to copy text from.
High ASCII and other encodings will be noted in the operand field,
not the opcode, so we no longer need these.
This removes the six input fields from the Pseudo-Op tab of app
settings. Values were stored as a serialized class in settings,
which generally works correctly as far as forward/backward
compatibility goes, so no worries there.
This also adds four "delimiter pattern" fields to the Code View tab,
allowing the user to customize how encoded strings are marked up
for the code list. The values aren't actually used yet.
Also, fixed an issue where changes to text fields on the Pseudo-Op
tab weren't raising the dirty flag.
We've been treating ASCII strings and instruction/data operands as
ambiguous, resolving low vs. high when generating output for the
display or assembler. This change splits it into two separate
formats, simplifying output generation.
The UI will continue to treat low/high ASCII as as single thing,
selecting the format appropriately based on the data. There's no
reason to have two radio buttons that are never both enabled.
The data operand string functions need some additional work, but
that overlaps substantially with the upcoming PETSCII changes, so
for now all strings set by the data operand editor are low ASCII.
The file format has changed again, but since there hasn't been a
release since the previous change, I'm leaving the file format
at v2. Code has been added to resolve the ASCII mode when loading
a v1 project file.
This removes some complexity from the assembly code generators.
We used to use type="String", with the sub-type indicating whether
the string was null-terminated, prefixed with a length, or whatever.
This didn't leave much room for specifying a character encoding,
which is orthogonal to the sub-type.
What we actually want is to have the type specify the string type,
and then have the sub-type determine the character encoding. These
sub-types can also be used with the Numeric type to specify the
encoding of character operands.
This change updates the enum definitions and the various bits of
code that use them, but does not add any code for working with
non-ASCII character encodings.
The project file version number was incremented to 2, since the new
FormatDescriptor serialization is mildly incompatible with the old.
(Won't explode, but it'll post a complaint and ignore the stuff
it doesn't recognize.)
While I was at it, I finished removing DciReverse. It's still part
of the 2005-string-types regression test, which currently fails
because the generated source doesn't match.
To avoid confusing the assembler, expressions with a leading
parenthesis like "(foo & $ffff) + 1" are prefixed with a "0+". This
is not necessary if the operand begins with a '#'.
(issue #16)
This adds a null check on the dfd argument in FormatDataOp() to see
if we can prevent a crash. The opcode/operand are presented as
"!FAILED!" to make it obvious to the user that something has gone
wrong. Hopefully this will allow capture of a project that exhibits
the problem.
We now insert parenthesis as needed. This can cause problems in
some situations, so we always prefix parenthetical expressions with
"0+", which looks goofy and is unnecessary for immediate operands.
But it does generate working source code.
Renamed the "simple" expression mode to "common", as it's not
particularly simple but is what you'd expect most assemblers to do.
(OTOH, life has been full of surprises.)
(issue #16)
Gave cc65 its own expression generator, as the precedence table seems
atypical if not unique. Configured 64tass to use the "simple"
expression mode.
Added some operations on a 32-bit constant to 2007-labels-and-symbols
to exercise the current worst-case expression (shift + AND + add).
Tweaked the Merlin expression generator to handle it.
(issue #16)