Add support for %type declarations using %nterm in Nonterminal Symbols - #485
Merged
Conversation
This PR add support for %type declarations using `%nterm` in Nonterminal Symbols. https://www.gnu.org/software/bison/manual/html_node/Type-Decl.html
Collaborator
|
What should happen if terminal like |
In bison when a terminal symbol is passed to `%nterm` it should give an error. But it doesn't yet.
It just ignores the terminal symbol and uses the nonterminal symbol.
For example in the following code, `EOI` is a terminal symbol and `EOI` is a nonterminal symbol. When `EOI` is passed to `%nterm` it should give an error but it doesn't.
```yacc
%{
// Prologue
%}
%token EOI 0 "EOI"
%nterm EOI
%%
program: /* empty */
;
```
In bison, it gives the following error
```
❯ bison test.y
test.y:6.8-10: error: symbol EOI redeclared as a nonterminal
6 | %nterm EOI
| ^~~
test.y:5.8-10: note: previous definition
5 | %token EOI 0 "EOI"
| ^~~
```
So this PR adds an error when a terminal symbol is passed to `%nterm`.
Member
Author
|
Thanks for catching that. Currently, no error occurred, but when I looked at the bison behavior, the following error occurred. So, I made lrama output error messages as bison works. Reproduce code: %{
// Prologue
%}
%token EOI 0 "EOI"
%nterm EOI
%%
program: /* empty */
;Error message: |
yui-knk
approved these changes
Dec 22, 2024
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This PR add support for %type declarations using
%ntermin Nonterminal Symbols. https://www.gnu.org/software/bison/manual/html_node/Type-Decl.html