Parser: fix IS [NOT] DISTINCT FROM right-operand precedence - #2443
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MohamedAbdeen-rs wants to merge 1 commit into
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Parser: fix IS [NOT] DISTINCT FROM right-operand precedence#2443MohamedAbdeen-rs wants to merge 1 commit into
MohamedAbdeen-rs wants to merge 1 commit into
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`IS DISTINCT FROM` and `IS NOT DISTINCT FROM` parsed their right operand with parse_expr, which starts at the lowest precedence and therefore absorbed every operator that followed, including AND and OR. So `a IS DISTINCT FROM b AND c` parsed as `a IS DISTINCT FROM (b AND c)` instead of `(a IS DISTINCT FROM b) AND c`, accepting a boolean operand where PostgreSQL takes the comparison as complete. PostgreSQL places IS below the comparison operators and above NOT, AND and OR. `Precedence::Is` already encodes exactly that, and the operator is dispatched with it; only the right operand ignored it. Every other infix operator in parse_infix parses its right operand with parse_subexpr(precedence), so do the same for these two. Operators binding tighter than IS still join the right operand, so `a IS DISTINCT FROM b + c` and `a IS DISTINCT FROM b = c` are unchanged, and a parenthesized conjunction still reaches it. Adds precedence tests for both spellings against AND, OR, NOT, `+`, `=`, parentheses, and a WHERE clause conjoining two of these comparisons.
This was referenced Aug 19, 2026
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Seems like a duplicate of #2436, could you please check and determine whether this PR should be closed in favour of the pre-existing one? |
I looked at both and I think #2436 is more complete. I suggest we close this PR. Thanks for your contribution @MohamedAbdeen-rs |
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IS DISTINCT FROMandIS NOT DISTINCT FROMparsed their right operand with parse_expr, which starts at the lowest precedence and therefore absorbed every operator that followed, including AND and OR. Soa IS DISTINCT FROM b AND cparsed asa IS DISTINCT FROM (b AND c)instead of(a IS DISTINCT FROM b) AND c.PostgreSQL places IS below the comparison operators and above NOT, AND and OR.
Precedence::Isalready encodes exactly that.