Raymond Toy pushed to branch rtoy-print-using-ryu at cmucl / cmucl Commits: e469d3aa by Raymond Toy at 2026-05-25T07:47:04-07:00 Fix tests after fixing ansi-test format.f.5 fix When d is unspecified and the shortest form doesn't fit in w, we need to print all digits so that round-tripping works by expanding the field instead of truncating. - - - - - 1 changed file: - tests/ryu.lisp Changes: ===================================== tests/ryu.lisp ===================================== @@ -367,18 +367,21 @@ (assert-equal " 1.0" (lisp::format-f 1d0 10 nil 0 nil nil nil))) -(define-test format-f.d-nil-with-w-shrinks +(define-test format-f.d-nil-with-w-no-shrink (:tag :format-f) - ;; d=nil with tight width: must shrink fractional digits via d2fixed. - ;; 3.141592653589793 has 16 fractional digits at shortest; w=8 only - ;; allows 6 (sign 0 + int 1 + dot 1 + frac 6 = 8). - (assert-equal "3.141593" - (lisp::format-f 3.141592653589793d0 8 nil 0 nil nil nil)) - (assert-equal "3.14159265" + ;; CLHS 22.3.3.1: when d is unspecified, the digit count is set so + ;; that the result reads back as an EQUAL float, with no extraneous + ;; trailing zeros. This is the round-trip count. When the result + ;; does not fit in w and no overflowchar is supplied, the field + ;; expands -- it does NOT shrink the digits, because doing so would + ;; produce a different float on read-back. (Earlier ryu code did + ;; shrink here; that change was needed to pass ANSI FORMAT.F.5.) + (assert-equal "1.234567" + (lisp::format-f 1.234567d0 6 nil 0 nil nil nil)) + (assert-equal "3.141592653589793" (lisp::format-f 3.141592653589793d0 10 nil 0 nil nil nil)) - ;; The shrink should round correctly: 5 with following digits rounds up. - (assert-equal "1.2346" - (lisp::format-f 1.234567d0 6 nil 0 nil nil nil))) + (assert-equal "3.141592653589793" + (lisp::format-f 3.141592653589793d0 8 nil 0 nil nil nil))) (define-test format-f.d-nil-with-w-overflow (:tag :format-f) View it on GitLab: https://gitlab.common-lisp.net/cmucl/cmucl/-/commit/e469d3aa23e307b29cf29ae7... -- View it on GitLab: https://gitlab.common-lisp.net/cmucl/cmucl/-/commit/e469d3aa23e307b29cf29ae7... You're receiving this email because of your account on gitlab.common-lisp.net. Manage all notifications: https://gitlab.common-lisp.net/-/profile/notifications | Help: https://gitlab.common-lisp.net/help