Classfile API proposal to integrate basic print functionality directly to ClassModel and MethodModel

[Adam Sotona]

Further reduction will require additional info about formatting. Actual list has very simple printers implementations:
            switch (node) {
                case Value v ->
                case ValueList vl ->
                case Mapping m
                case BlockList bl ->
                case BlockMapping bm ->
                case Comment c ->
            }
Replacing all simple values with list of values will wrap everything into square brackets and significantly reduce user readability.
Or dynamic detection of single value in a list will destroy any schema for parsing.

Visual difference of rendered Mapping and BlockMapping is significant in all three formats.

The key here means a mapping key in YAML, object key in JSON and element or attribute name in XML, so it defines a key in the schemas.
BlockMapping renders as multi-line mapping in YAML, as multi-line object in JSON and as multi-line nested elements in XML.
While Mapping renders as single-line flow in YAML, as single-line object in JSON and as single  element with attributes only in XML.
Dynamic detection by content will make the print very unstable and unfriendly for user reading (for example one method will be collapsed, while the other will expand).

I don’t see much space for reduction without losing visual features.
On 25.07.2022 19:28, "Brian Goetz" <brian.goetz at oracle.com> wrote:

That's a good move.  Can we push further?  We have types here for mapping a key to a:

 - list of simple values
 - list of arbitrary fragments
 - list of printables
 - list of list of printable (blocklist)


On 7/25/2022 1:20 PM, Adam Sotona wrote:
Or maybe we could let the printer to auto-quote as needed by the actual value in the context of the actual format 😊
So yes, it can be reduced:

public sealed interface Printable {

    public String key();

    public sealed interface Fragment extends Printable {}

    public record Value(String key, String ConstantDesc value) implements Fragment {}

    public record Quoted(String key, String value) implements Fragment {}

    public record Decimal(String key, int value) implements Fragment {}

    public record ValueList(String key, List<String ConstantDesc> values) implements Fragment {}

    public record QuotedList(String key, List<String> values) implements Fragment {}

    public record Mapping(String key, List<Fragment> fragments) implements Printable {}

    public record BlockMapping(String key,  List<Printable> printables) implements Printable {}

    public record BlockList(String key,  List<BlockMapping> blockMappings) implements Printable {}

    public record Comment(String key) implements Printable {}


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