make comparison with scratchblocks functionality

[pdawyndt]

check the following pages to see if Scratch-LN supports all the scratchblocks functionality (for Scratch 2.0 blocks)

• [ ] block plugin
• [ ] block plugin/syntax
• [ ] block plugin style guide

add a section to the Scratch-LN website that contains

• [ ] a list of scratchblocks features that are not supported by Scratch-LN
• [ ] a list of scratchblocks features that are supported in a different way by Scratch-LN
• [ ] a list of Scratch-LN features that are not supported by scratchblocks

[pdawyndt]

additional features in comparison to scratchblocks

• Scratch-LN generates fully functional Scratch 3.0 blocks where scratchblocks generates SVG or PNG representations of Scratch blocks; right-clicking the Scratch 3.0 blocks generated by Scratch-LN allows to save them as a PNG
• apart from the Scratch comments supported by scratchblocks (in Scratch-LN they are enclosed in between bars | ... | and are block comments instead of line comments), Scratch-LN also supports Scratch-LN comments (both line comments // ... and block comments /* ... */) that do not have a corresponding representation in Scratch 3.0 blocks
• Scratch-LN has identifiers that support external referencing of individual blocks and disambiguation of custom or built-in blocks having the same signature
• Scratch-LN uses curly braces around block arguments; in most cases (except around number arguments or when annotating arguments with identifiers or comments), these curly braces are optional
• Scratch-LN issues clear warning or error messages when invalid syntax is used (not yet implemented), whereas scratchblocks does not check the validity of the syntax
• Scratch-LN allows to drop the trailing question mark on built-in reporter blocks such that e.g. <mouse down?> can be written as <mouse down?>; the question mark can also be preceded or followed by additional spaces and/or tabs
• Scratch-LN supports shorthand notation for RGB-colors: e.g. #AABBCC can be written using the shorthand notation #ABC
• in Scratch-LN the then keyword is optional in conditional statements, where it is mandatory in scratchblocks
• Scratch-LN supports the option ::user-defined as an alias for the option ::custom
• Scratch-LN supports the option ::local as an alias for the option ::custom-arg

[pdawyndt]

alternative features in comparison to scratchblocks

• the Scratch-LN implementation uses a formal grammar definition for the language; this makes it easier to extend or adjust the language
• Scratch-LN uses as a block delimiter either a newline (\n; as in scratchblocks), a semicolon (;) or a combination of a semicolon followed by a newline (possibly with some intermediate spaces and/or tabs); the use of semicolons allows to put Scratch-LN code on a single line in contexts that do not support multiline text; scratchblocks does not support a semicolon as a delimiter
• stacks of blocks are separated by at least two consecutive delimiters, at least one comment (possibly surrounded by delimiters), a hat block or a cap block; when using newlines as delimiters, this mimicks how stacks are separated graphically: blocks can either be snapped together or not (represented by having the blocks on consecutive lines or separated by one or more empty lines); no block can be attached on top of hat blocks and no block can be attached below cap blocks
• string literals are enclosed in between square brackets in scratchblocks (e.g. [Hello!]), but are enclosed in between curly braces ({text}), double quotes ("text") or a combination thereof ({"text"}) in Scratch-LN (@Ellen102 does Scratch-LN officially also supports the square brackets as a string delimiter, because this seems to work in the preview?)
• in Scratch-LN, square brackets are only used as delimiters for dropdown inputs in Scratch 3.0 blocks; as a result dropdown inputs don't need the extra suffix v to discriminate them from text inputs as in scratchblocks
• number literals have to be enclosed in between curly braces or double quotes or both in Scratch-LN, whereas they have to be enclosed in between round brackets in scratchblocks; the latter however prevents to represent variables whose name can be interpreted as a number, which is allowed by Scratch 3.0
• in Scratch-LN color literals are not enclosed in square brackets (the pound sign # is sufficient to recognize a color literal) but can optionally be enclosed in curly braces (as with all arguments)
• in defining custom blocks, scratchblocks makes a distinction between number arguments (round brackets) and string arguments (square brackets), whereas Scratch-LN does not make a distinction (curly braces) because Scratch doesn't either
• scratchblocks automatically tries to infer whether or not a variable is a list, whereas Scratch-LN always requires the ::list modifier for list variables (explicit is better than implicit)
• scratchblocks represents calls to custom blocks that have or haven't been defined in a different way (closed world view), whereas Scratch-LN represents all custom blocks in the same way (open world view)
• i18n support: Scratch-LN supports automatic translation of Scratch 3.0 blocks (single source principle) (not yet implemented), whereas scratchblocks supports block templates in multiple languages

[pdawyndt]

missing features in comparison to scratchblocks

• Scratch-LN requires escaping of hash symbol (#) in tags, e.g. variable names such as (costume \#) do no need the escaping in scratchblocks and can simply be written as (costume #)
• scratchblocks allows to drop the closing square brackets (]) and parentheses ()) but Scratch-LN doesn't because it is considered bad style (also in the scratchblocks style guide)
• scratchblocks supports modifiers to set specific colors and shapes for blocks (not supported in Scratch 3.0, may be supported as a Google Blockly extension)
• scratchblocks supports custom C-shape blocks (not supported in Scratch 3.0)
• scratchblocks supports snap! extensions (not supported in Scratch 3.0)
• scratchblocks supports an ellipsis block (...) (may be supported as a Scratch 3.0 extension)

[martinohanlon]

I noticed a couple of other tools or features which scratchblocks offers, which I personally find really useful.

Having a generator which will "download" the scripts from the scratch website and turn them into scratchblocks code scratchblocks.github.io/generator, super useful when creating projects.

The ability to highlight or "cross out" blocks, which is really useful in creating projects where you want to specifically highlight a block to change or a block to remove.

[pdawyndt]

@Ellen102 once we have support for extensions, we could make an extension for "crossed out" blocks; instead of crossing them out, we could either give them a grey color or make them semitransparent (if this is supported by Google Blockly)

If the blocks aren't set as read-only, users could then also take the manual action of removing the "crossed out" block to see the end result.