Problem:
- Much of the `GenericLexer` can be `constexpr`, but is not.
Solution:
- Make it `constexpr` and de-duplicate code.
- Extend some of `StringView` with `constexpr` to support.
- Add tests to ensure `constexpr` behavior.
Note:
- Construction of `StringView` from pointer and length is not
`constexpr`-compatible at the moment because the VERIFY cannot be,
yet.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
This allows going back one character at a time, and then re-consume
previously consumed chars.
The code I need this for looks something like this:
ASSERT(lexer.consume_specific('\\'));
if (lexer.next_is("foo"))
...
lexer.retreat();
lexer.consume_escaped_character(); // This expects lexer.peek() == '\\'
This finally takes care of the kind-of excessive boilerplate code that were the
ctype adapters. On the other hand, I had to link `LibC/ctype.cpp` to the Kernel
(for `AK/JsonParser.cpp` and `AK/Format.cpp`). The previous commit actually makes
sense now: the `string.h` includes in `ctype.{h,cpp}` would require to link more LibC
stuff to the Kernel when it only needs the `_ctype_` array of `ctype.cpp`, and there
wasn't any string stuff used in ctype.
Instead of all this I could have put static derivatives of `is_any_of()` in the
concerned AK files, however that would have meant more boilerplate and workarounds;
so I went for the Kernel approach.
Since commit 1ec59f28ce turns the ctype macros
into functions we can now feed them directly to a GenericLexer! This will lead to
removing the ctype adapters that were kind-of excessive boilerplate, but needed as
the Kernel doesn't compile with the LibC.
The `consume_quoted_string()` can now take an escape character. This allows it
(for example) to capture a string's enclosing quotes. The escape character is
optional by default.
You can also consume and unescape a quoted string with the eponymous method
`consume_and_unescape_string()`. It takes an escape character as parameter
(backslash by default). It builds a String in which common escape sequences
get... unescaped :^) (e.g. \n, \r, \t...).
