* Make architecture implementations virtual functions
- Easier to add new architectures (add implementation to implementation.cpp)
- Easier to add new algorithms / functions to architecture selection
(add to implementation.h, implement)
- Automatically select best implementation in static initialization
- Allow user to explicitly select implementation with a string (i.e.
parameter)
- Allow user to inspect current implementation name/description
- Allow user to list available implementations
- Eliminate architecture enum and architecture-based templating
- Add noexcept in non-inline functions
* Move implementation static methods to their own classes
* Detect best supported implementation on first use
* available_implementationsI() -> available_implementations
This creates a "document" class with only user-facing document state (no parser internals).
- document: user-facing document state
- document::iterator: iterator (equivalent of ParsedJsonIterator)
- document::parser: parser state plus a "docked" document we parse into (equivalent of ParsedJson)
Usage:
```c++
auto doc = simdjson::document::parse(buf, len); // less efficient but simplest
```
```c++
simdjson::document::parser parser; // reusable parser
parser.allocate_capacity(len);
simdjson::document* doc = parser.parse(buf, len); // pointer to doc inside parser
doc = parser.parse(buf2, len); // reuses all buffers and overwrites doc; more efficient
```
John Keiser