These SuffixOp nodes have their own ast.Node tags now:
* ArrayInitializer
* ArrayInitializerDot
* StructInitializer
* StructInitializerDot
Their sub-expression lists are general-purpose-allocator allocated
and then copied into the arena after completion of parsing.
throughput: 72.9 MiB/s => 74.4 MiB/s
maxrss: 68 KB => 72 KB
The API is also nicer since the sub expression lists are now flat arrays
instead of singly linked lists.
Instead of being its own node, it's a struct inside FnProto.
Instead of FnProto having a SinglyLinkedList of ParamDecl nodes,
ParamDecls are appended directly in memory after the FnProto.
throughput: 72.2 MiB/s => 72.9 MiB/s
maxrss: 70 KB => 68 KB
Importantly, the API is improved as well since the data is arranged
linearly in memory.
This makes fields and decl ast nodes part of the Root and ContainerDecl
AST nodes.
Surprisingly, it's a performance regression from using a singly-linked
list for these nodes:
throughput: 76.5 MiB/s => 69.4 MiB/s
However it has much better memory usage:
maxrss: 392 KB => 77 KB
It's also better API for consumers of the parser, since it is a flat
list in memory.
std.ast uses a singly linked list for lists of things. This is a
breaking change to the self-hosted parser API.
std.ast.Tree has been separated into a private "Parser" type which
represents in-progress parsing, and std.ast.Tree which has only
"output" data. This means cleaner, but breaking, API for parse results.
Specifically, `tokens` and `errors` are no longer SegmentedList but a
slice.
The way to iterate over AST nodes has necessarily changed since lists of
nodes are now singly linked lists rather than SegmentedList.
From these changes, I observe the following on the
self-hosted-parser benchmark from ziglang/gotta-go-fast:
throughput: 45.6 MiB/s => 55.6 MiB/s
maxrss: 359 KB => 342 KB
This commit breaks the build; more updates are necessary to fix API
usage of the self-hosted parser.
