`Pattern` is intended to pilot some changes I would like to apply to all our sum types:
- The alternatives are expressed as derived classes rather than members of a `std::variant`.
- The alternatives are classes in the [style guide sense](https://google.github.io/styleguide/cppguide.html#Structs_vs._Classes), meaning they can have invariants, but can't have public data members.
- Creating an object is expressed using a constructor rather than a factory function.
- Accessing an alternative is expressed as a cast (using LLVM's RTTI system) rather than `std::get` or a `Get` method.
Co-authored-by: Jon Meow <46229924+jonmeow@users.noreply.github.com>
- Switch code to llvm::raw_ostream as part of standardizing output forms.
- Preferring llvm::raw_ostream over std::ostream because other tooling code should be expected to rely on llvm more closely, and an overall preference towards library consistency.
- There are a couple spots in syntax/ that still use std streams, but I'd prefer to take a separate PR to see how best to address those.
- std::boolalpha doesn't work with llvm, so I've implemented equivalent in a couple places (not enough that it felt like worth making a helper function).
- Implement Print(ostream) as consistently as we can, as an instance member.
- This facilitates the use of the common/ostream.h template to provide operators.
- Preferring this approach so that Print is easily accessible via gdb, per suggestion on #executable-semantics.
- Switch code currently calling `type->Print(ostream)` to instead do `ostream << *type`.
- Remove the unused `PrintTypeEnv`, nothing used it and the declaration didn't match the definition.
* Move nontrivial logic out of `parser.ypp` into `FieldList`, rename it to `ParenContents`, make it a class, and add tests
* Use a `FieldInitializer` struct instead of `std::pair<std::string, Expression*>` to represent the fields of a tuple
Slowly bringing this into line with Bison's C++ example parser
so we can use strong semantic values for symbols rather than
leaking pointers. First step is to thread a `ParseAndLexContext`
object through the whole syntactic analysis state, like the
example has. In the example, it's called `driver`.
Co-authored-by: Geoff Romer <gromer@google.com>
* Make `field_list` always a list.
* Create separate `paren_expression` and `tuple` nonterminals
* Rename expression_or_field_list.* to field_list.*
Co-authored-by: Jeremy G. Siek <jsiek@indiana.edu>
Notes versus what jsiek wrote:
- This adopts Bazel for building.
- System-local versions of bison/flex are used. I found https://github.com/jmillikin/rules_bison, but those print a lot of warnings (things like -Wsign-compare IIRC) which makes builds hard to read. Plus I think the underlying bison_cc_library rule didn't work, so this would really only get a hermetic bison/flex build (helpful, but didn't seem worth more time).
- I'm adding in a .bazeliskrc to push a somewhat more standard choice of bazel versions. I noticed I was getting unstable versions by default, possible Google-specific, but seemed good to include.
- The `-lpthread` kludge.
- Turn all of the examples into golden tests.
- Including adding a golden test rule.
- Fixed various style guide issues. For example:
- Fixing function names to be CamelCase instead of snake_case (https://google.github.io/styleguide/cppguide.html#Function_Names)
- Removed exception use (https://google.github.io/styleguide/cppguide.html#Exceptions)
- File name fixes (https://github.com/carbon-language/carbon-lang/blob/trunk/docs/project/cpp_style_guide.md#file-names)
- Dropped `using` of `std` names -- I believe this is preferred (maybe we should be explicit about this in the Carbon style guide)
- Switched `enum` uses to `enum class` for ease-of-identification.
- Spent some time breaking out files to hopefully be easier to read/edit pieces, and understand relations between structs.
- Added `code requires` to `syntax.ypp` to address include issues
Possibly other things -- but the fundamental structure is, I believe, unchanged. I put in the golden tests pretty early to ensure I wasn't mutating output/results.
Jon Meow
Geoff RomerandJon Meow
Dave AbrahamsandGeoff Romer
