Does your DSL little language need operator precedence?

You can ignore precedence in the grammar, and then use a pratt parser or shunting yard or something to parse the precedence.

But yes, it does need it, usually. And it's not a huge thing to implement. I usually implement it in the grammar, with inline node folding inserted for left associative operators, which gets me a very nice clean AST.

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bitwize 2 days ago | parent | prev | next [-]

Not if it's s-expression-based! (laughs in smug lisp weenie)

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aleph_minus_one 2 days ago | parent [-]

Or, if the programming language uses infix binary operators:

Not if the programming language has evaluation order from left to right, e.g.

2+3*4

is evaluated as

(2+3)*4.

For example J uses this kind of evaluation.

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Someone 2 days ago | parent | next [-]

J is APL-inspired, and APL is right-associative, so that would surprise me. https://www.jsoftware.com/help/jforc/preliminaries.htm#_Toc1... agrees with that, saying

“All J verbs (functions and operators) have the same priority and associate right-to-left. For example, a b + c is equivalent to a * (b + c), not (a * b) + c.”*

Your point about not needing operator precedence still stands, though.

	▲	aleph_minus_one 2 days ago \| parent [-]
		> J is APL-inspired, and APL is right-associative, so that would surprise me. You are indeed right (it has been quite a long time since I experimented with J): > https://www.jsoftware.com/help/jforc/preliminaries.htm (scroll down to "Order of Evaluation")

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lmz 2 days ago | parent | prev [-]

Smalltalk also.

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fjfaase 2 days ago | parent | prev | next [-]

Just a single function per level is sufficient for implementing both right and left association. I do not see the problem.

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recursivedoubts 2 days ago | parent | prev | next [-]

hyperscript has some operator precedence, but within a given general precedence level you have to explicitly parenthesize if you use different operators:

https://github.com/bigskysoftware/_hyperscript/blob/06f9078a...

this eliminates most practical precendence questions

NB: one thing that may strike people as strange is that the parse methods are on the parse elements themselves, I like to localize everything about a parse element in one place

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aappleby 2 days ago | parent | prev [-]

Yes, but it doesn't need any funny parsing trick to handle them. Just parse the whole statement as a list of expressions joined by operators, and then you can convert the flat list into a precedence-respecting tree with a few lines of code and an operator-to-precedence table.

	▲	childintime 2 days ago \| parent [-]
		Yes, it's as easy as that. Or check out Jonathan Blow on precedence. The infamous dragon book convinced people to use the wrong tools and have the wrong mindset. It was a work of incompetence. There were no dragons, but the book itself.