I would like an operator that has higher precedence than :*, but is left associative. I found there is no pre-defined symbol has these two properties at the same time. Since I’m working with strings coming from user input, I guess I can define a macro or something to change the precedence before parsing. But I’m not sure how.
For example, I would like "a⊗ b*c⊗ d" to be parsed to (a⊗ b)*(c⊗ d).
Since you are working on strings, you don’t need a macro, you need a parser.
You can make your from scratch or use tools like
https://lcsb-biocore.github.io/PikaParser.jl/stable/
https://gkappler.github.io/CombinedParsers.jl/dev/man/user/
I don’t think you can use Julia’s parser for this because it can’t distinguish between
julia> Meta.parse("(a⊗b*c)⊗d")
:(((a ⊗ b) * c) ⊗ d)
julia> Meta.parse("a⊗b*c⊗d")
:(((a ⊗ b) * c) ⊗ d)
Though maybe you can modify the output of the JuliaSyntax parser using the fancy parenthesis-tracking stuff — probably not worthwhile.
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Thank you, I’m trying to write expression parser myself.