ocaml.lang.correctness.useless-compare.useless-compare

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This comparison is useless because the expressions being compared are identical. This is expected to always return the same result, 0, unless your code is really strange.

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Defintion

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rules:
  - id: useless-compare
    patterns:
      - pattern-either:
          - pattern: compare $X $X
          - pattern: $MODULE.compare $X $X
    message: This comparison is useless because the expressions being compared are
      identical. This is expected to always return the same result, 0, unless
      your code is really strange.
    languages:
      - ocaml
    severity: ERROR
    metadata:
      category: correctness
      technology:
        - ocaml
      license: Commons Clause License Condition v1.0[LGPL-2.1-only]

Examples

useless-compare.ml

let test a b =
  (* ruleid:useless-compare *)
  let c = compare (a+b) (a+b) in
  if c <> 0 then c
  else
    compare a b

let test a b =
  (* ruleid:useless-compare *)
  let c = Int.compare (a+b) (a+b) in
  if c <> 0 then c
  else
    compare a b