Sorry about the big change, this is hard to split. ParenContents is used by both, templated, and expects the same pointer type. While I could duplicate ParenContents with some ExpressionParenContents or PatternParenContents, that seems a little kludgy versus a single large change handling both. The worst of it is that Expression is already pretty sweeping, Pattern is really just incrementally adding.
That said, I believe this includes a couple fixes I found with incorrect use of dyn_cast in typecheck.cpp (checked nullptr at the wrong step in 2 code locations). There's also a missing `*` in member.cpp this caught. I adjust passing of expressions for Return due to nullness (I felt adding another constructor was the best solution).
I add a `.Release()` to BisonWrap due to things like `$3.first` needing some way to work through BIsonWrap. I felt this was better than `operator->`, but feel free to comment if you prefer the other path (`.Release()` conveniently lets me do pair unwrapping, so it felt a better solution).
I do add a TODO to think about better Ptr-to-Ptr cast<> support too, though, as that doesn't work cleanly with LLVM's infra. But so far it seems to only come up in one spot, so I'm not prioritizing it.
This opens up a path for switching `int line_num` to a `Location loc`, which I want to do for tracking filenames of code. But I don't think we should have a default constructor on `Location` to avoid mistakes, and switching FunctionDefinition to an arena alloc seems more consistent anyways.
It was in my mind to add String in order to support libraries in `package`. `print` is added in order to have a String go to stdout. I've tried to do `print` in a way that won't be too hard to add other printable types, but it's probably also somewhat optional here -- that is, if desired, I could remove it. But it was a lot easier to doublecheck `\n` behavior with it, and I suspect it'll be helpful in other tests if it supports more value types.
On the side, this also fixes dereferencing in Pattern/Expression Print() calls, which I was noticing printing pointers instead of values. This may be another argument for moving away from passing pointers, since this seems to be a difficult-to-catch error.
Co-authored-by: Geoff Romer <gromer@google.com>
This creates a ReturnExpression. A separate change should enforce that an implicit return of `()` is only allowed in functions that have an implicit return type of `()`, and I think the structure taken here should ease that.
`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>
This adds a test for invalid characters (that would've failed before, because the printed char isn't escaped). Not sure if there's a good way to test the PrintDiagnostic code, as it appears to occur on bison parser errors, which I'm just not sure how to trigger.
Note this makes some structural choices that I'm not sure how popular they'll be... Most notably, I could remove `DeclarationKind` because I'm using `std::visit` and `Declaration::Visitor` in reality. I could go to `switch(tag())` instead, but I'm wondering if this approach will be well received for the separation of ownership. Alternatively, I could move `Declaration` around so that it actually implements the things like `TopLevel` -- I did feel weird with the old structure of typecheck.cpp implementing members of declaration.h, though.
Pretty much any names will be awkward, since these types represent cases where an `Expression` is not an expression, and a `Value` is not a value, but we can at least be more explicit about the fact that they represent bindings rather than variable usages.
- `Kind` enumerator names always match the corresponding factory function, accessor, and type names (if any).
- All abbreviations in those names are expanded.
- Those names always have a suffix to disambiguate expressions from values.
`VarTV` is excluded from these changes because there's a pending PR to remove it.
This ensures that the factory functions correspond 1:1 with expression kinds, and MakeOp covers their use cases with minimal syntactic overhead now that it can take initializer list arguments.
The presence or absence of whitespace is used to determine which
operator is in use, following the rules described in #520.
Support for prefix * dereference operator follows #523.
Co-authored-by: Geoff Romer <gromer@google.com>
Going through tests, funptr1.6c is the main spot I see a real change, I added parens to get around an issue parsing fnty.
Co-authored-by: Geoff Romer <gromer@google.com>
* changed union of Statement to be private
* changed the union in Expression to be private
* changed union in Value to be private
* changed AST constructors to be static methods
* updates to syntax unit tests
- Give unary `-` and `not` the same precedence as in C++
- Add detail to parse error messages, and make the --trace flag also enable parser debug tracing
- Make any new shift-reduce conflicts into build errors
- Use `%precedence` rather than `%nonassoc` where possible, in order to catch more grammar bugs at build time
* 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
* AST and syntax for delimited control
* stashing for later
* a little more progress
* progress on delimited continuations
* delimit, suspend, and resume implemented (draft)
* example that generates the natural numbers
* fixes
* tinkering
* changed demo to experimental
* comments and name changes
* describe delimited continuations in the README
* renamed Snapshot to Continuation, edits to comments
* Update executable_semantics/ast/statement.h
improve comment for MakeDelimitStmt
Co-authored-by: Dave Abrahams <dabrahams@google.com>
* Update executable_semantics/interpreter/interpreter.cpp
remove snake_case
Co-authored-by: Dave Abrahams <dabrahams@google.com>
* edits to comments, change name of variable
* updates to handle review edits
* trailing whitespace
* fixes to delimited continuations, added more tests, also fixed assignment to do a copy
* improvements from Geoffrey
* new test from Geoffrey, fix for empty blocks
* more suggestions from Geoffrey
* more tests for delimited continuations, renaming some of them
* renamed test files
* improve a comment
* sketch of creating continuation
* initial implementation of shift/reset style continuations
* more documentation
* fix some camel case
* implemented deep copy of continuations, added a test case for it
* fixed a bug and got the recursive test case working
* removed __delimit, polished up __continuation
* back to shallow copy for continuations
* suggestions from Geoffrey
* removed structured binding (for now)
* Update executable_semantics/ast/expression.cpp
Co-authored-by: Geoff Romer <gromer@google.com>
* responses to Geoffrey
Co-authored-by: Dave Abrahams <dabrahams@google.com>
Co-authored-by: Geoff Romer <gromer@google.com>
Jon Meow
Jeremy G. SiekandJon Meow
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