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Outdated suggestions cannot be applied.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.
Since we had some problems with
expr
I rewrote the parsing logic, which then again ballooned into rewriting everything (as seems to happen to me often these days...).I removed the tokenization, because that's not correct; each token could also be a valid string in another position. I also made the AST so that it does not have slices of values, but a fixed number for each operation. This makes the whole thing much less error prone. The parser is replaced with a fairly simple yet effective recursive descent parser.
The total implementation is also much smaller (especially considering that some lines are new tests).
Limitations:
String
values, which leads to unnecessary conversions between strings and integers.expr '(' 1 / 0
, which in GNU gives a division by zero error and a syntax error here)