Rename value categories to expression categories based on [Discord discussion](https://discord.com/channels/655572317891461132/753021843459538996/1092924035517665332) regarding naming and behavior.
>* let expression -> value expression
>* var expression -> reference expression
>* located expression -> initializing expression
>So:
>- "value expressions" produce values (with no associated location). "reference expressions" produce a location of an existing value. "initializing expressions" take a location and initialize it.
>- A let binding is initialized by a value expression, because lets represent values (with category conversions performed as needed, but if a conversion is performed from a different category of expression, the value of the object is pinned for the lifetime of the let).
>- A var binding is initialized by an initializing expression, without performing a copy (with category conversions performed as needed, calling a copy constructor if the initializer is a different expression category).
>- The & operator requires a reference expression, and it's an error to give it other kinds.
>- The left-hand side of . requires a value expression when calling a function with a non-addr receiver, and requires a reference expression when calling a function with an addr receiver (it's an error to give it a value expression, and for an initializing expression, a temporary is materialized).
Changes
* Rename "value category" to "expression category"
* Rename Var and Let value categories to Value, Reference, and Initializing expression
* Rename `lvalue` to `location` (most of the time)
libprotobuf_mutator and abseil have warnings that are already fixed in newer versions.
bison outputs code that hits new warnings; there I'm just silencing it because testing a newer bison version is more difficult.
Fixes#1650Fixes#1660
We fundamentally have cyclic references between declarations,
statements, expressions, and patterns, and there's no meaningful
layering between them. Combine them into a single build target.
Components such as paren_contents, static_scope, and library_name that
are defined without reference to specific AST nodes are kept as separate
BUILD targets.
* test cases for raw string literals
* raw string literal implementation
* match as block string if starting with triple ", and better error message for simple string
except for *#"""#*
* fix broken test case
block string literal cannot be one line
* test cases for raw string literals
* raw string literal implementation
* match as block string if starting with triple ", and better error message for simple string
except for *#"""#*
* fix broken test case
block string literal cannot be one line
* removed unused initial value
* rename flag to indicate multi-line string and remove comment
* use * to get value from std::optional
* clean-ups
* removed skip_scan flag and directly return in case of a single line string starting with #+\'\'\'
* Updated error message: simple string -> single-line string.
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
* Updated test cases according to changes in error message
* Removed counting_hashtag flag.
* Implemented ScanHelper class to handle scanning
* Fixed explanation of ReadHashTags.
* Addressed PR comment.
* Clarify that scan_helper holds the source text.
* Addressed PR comments.
* Updated error messages in test cases.
* Added const keyword to return type of GetCurrentStr().
* addressed PR comments.
1. Moved ScanHelper class to lex_scan_helper.h and lex_scan_helper.cpp.
2. Moved ReadHashTags and Process* functions to lex_scan_helper.cpp. Moved YY_USER_ACTION, SIMPLE_TOKEN and ARG_TOKEN to lex_helper.h. Added a wrapper function YyinputWrapper to call static function yyinput in lexer.lpp.
3. Renamed ScanHelper with StringLexHelper.
4. Modified BUILD accordingly.
5. Renamed data members and functions.
* Addressed PR comments.
1. Adjusted order to keep ret usage close.
2. Used resize to construct the string to avoid creation of temp string.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
* Removed the multi_line flag and skip_read field to improve readability.
* Copied default parameter value to definition of UnescapeStringLiteral.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
* Copied default parameter value to definition of ParseBlockStringLiteral.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
* Prefix CARBON_ to SIMPLE_TOKEN and ARG_TOKEN macros.
* Rollback redefinition of arguments.
* Updated comment on the flex macro.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
* Updated wording.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
* Moved the EOF error out of the loop.
* Removed duplicated declaration.
* Changed type of `hashtag_num` and `leading_quotes` to int.
* Minor fix: string copy.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
* Added comment on YyinputWrapper.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
* Garmmar in comment.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
* Added check of eof before readling next char.
* Minor updates based on PR comments.
* Minor changes to address PR comments.
* Used a clearer way to calculate `hashtag_num` and `leading_quotes`. Switched back to indicate muti-line string with a flag.
* Directly copy StringRef for compilation error message.
* Make str_with_quote const as we don't change it.
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
* Added TODO for unsupported cases.
* Fixed a typo.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
`.Self` is modeled as a new kind of expression, `DotSelfExpression`. Name resolution associates each occurrence of a `DotSelfExpression` with a generic binding, much like for an `IdentifierExpression`.
Both `:!` bindings and `where` expressions bring `.Self` into scope. The tentative intent is that if there are multiple `.Self`s in scope and they refer to different bindings, the result of using a `.Self` expression is an ambiguity error, but that is not implemented in this patch. Instead, like for `IdentifierExpression`s, we find the innermost enclosing definition of `.Self`.
`.Foo` expressions are rewritten to `.Self.Foo`, but this isn't enough to make them do anything useful, because associated constants aren't supported in general yet.
I'm treating my PR to mypy bazel integration as dead in the water. Abandoning that approach, this seems to work reasonably well as a replacement. It's actually a slightly newer version of mypy too -- the bazel integration was stuck on an old version.
Note I don't think we're losing much: we shouldn't be writing too much python.
Adrien Leravat
Jon Ross-Perkins
Richard Smith
