{"abstract":"Carets are placed at the logical index instead of the visual slot.","category":"Bidirectional text layout","checks":8,"contract":"Input [levels, logical caret offset k, affinity]. Characters are one unit wide and visually ordered by level reversal. Affinity \"after\" attaches the caret to the leading edge of character k (if k < n), otherwise to the trailing edge of character k-1; offset 0 always uses the leading edge of character 0. The leading edge of an LTR character is its left side, of an RTL (odd) character its right side. Return the visual x.","evaluation_group":"w2-bidirectional-text-layout-caret-position","failed_approach":"Mirroring the slot numbers is not the inverse permutation.","family":"w2-bidirectional-text-layout-caret-position-position-inverse-map","id":"FA-80646","implementations":{"attempt":{"sha256":"c7fcf18668a8ab663404974354aa02323807159a8e385bf325875ec3b540cf86","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    def reorder(lv):\n        vis = list(range(len(lv)))\n        odd = [l for l in lv if l % 2 == 1]\n        if not odd:\n            return vis\n        for lev in range(max(lv), min(odd) - 1, -1):\n            i = 0\n            while i < len(vis):\n                if lv[vis[i]] >= lev:\n                    j = i\n                    while j < len(vis) and lv[vis[j]] >= lev:\n                        j += 1\n                    vis[i:j] = vis[i:j][::-1]\n                    i = j\n                else:\n                    i += 1\n        return vis\n    \n    levels, k, affinity = x\n    n = len(levels)\n    if n == 0:\n        return 0\n    vis = reorder(levels)\n    pos = [0] * n\n    for v, i in enumerate(vis):\n        pos[i] = n - 1 - v\n    if affinity == 'after' and k < n or k == 0:\n        j = k\n        leading = True\n    else:\n        j = k - 1\n        leading = False\n    rtl = levels[j] % 2 == 1\n    if leading:\n        return pos[j] + 1 if rtl else pos[j]\n    return pos[j] if rtl else pos[j] + 1\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: position inverse map', [[2, 2, 2, 4, 4, 4, 4, 1, 1], 7, 'before'], 9), ('regression: position inverse map', [[2, 2, 2, 2, 2, 2, 2, 1], 2, 'after'], 3), ('regression: position inverse map', [[2, 2, 1, 1], 0, 'after'], 2), ('regression: position inverse map', [[1, 2, 2], 1, 'after'], 0), ('caret at direction boundary', [[0, 0, 1, 1], 2, 'before'], 2), ('line start before', [[1, 1, 0], 0, 'before'], 2), ('control layout', [[3, 0, 0, 0, 2, 2, 2], 3, 'after'], 3), ('control layout', [[4], 1, 'before'], 1)], [('regression: position inverse map', [[2, 2, 2, 2, 2, 2, 2, 2, 1], 6, 'after'], 7), ('regression: position inverse map', [[1, 1, 1, 1, 1, 2, 2, 2, 2, 1], 6, 'before'], 2), ('partial-repair probe', [[0, 0, 0, 3, 1, 1, 1, 1, 1, 1], 5, 'before'], 8), ('partial-repair probe', [[1, 1, 0, 0, 0, 0, 0, 0], 5, 'before'], 5), ('caret at direction boundary', [[0, 0, 1, 1], 2, 'before'], 2), ('line end', [[1, 1, 1], 3, 'after'], 0), ('control layout', [[3], 1, 'before'], 0), ('control layout', [[1], 1, 'before'], 0)], [('regression: position inverse map', [[2, 2, 2, 2, 2, 3, 3, 2, 1], 0, 'before'], 1), ('regression: position inverse map', [[3, 3, 2, 2, 2, 2, 2, 2, 1, 1], 7, 'after'], 9), ('partial-repair probe', [[2, 2, 2, 2, 4, 2], 4, 'before'], 4), ('partial-repair probe', [[1, 1, 1, 1, 0, 0, 0, 0, 0, 2], 2, 'after'], 2), ('caret at direction boundary', [[0, 0, 1, 1], 2, 'before'], 2), ('same boundary after', [[0, 0, 1, 1], 2, 'after'], 4), ('control layout', [[1, 2, 1, 1, 3, 3, 3], 3, 'after'], 4), ('control layout', [[3], 1, 'before'], 0)], [('regression: position inverse map', [[1, 1, 1, 1, 2, 2], 5, 'before'], 1), ('regression: position inverse map', [[2, 2, 1, 1, 1, 1, 2, 2, 2], 2, 'after'], 7), ('partial-repair probe', [[3, 3, 3, 0, 0, 0, 3], 5, 'after'], 5), ('partial-repair probe', [[3, 3, 3, 3, 3, 3, 3], 0, 'before'], 7), ('line end', [[1, 1, 1], 3, 'after'], 0), ('line start before', [[1, 1, 0], 0, 'before'], 2), ('control layout', [[1], 0, 'before'], 1), ('control layout', [[2, 2, 1, 1, 1], 3, 'before'], 2)], [('regression: position inverse map', [[4, 4, 3, 3, 3, 3, 2, 2, 2], 2, 'before'], 6), ('regression: position inverse map', [[2, 2, 1, 1], 0, 'after'], 2), ('regression: position inverse map', [[1, 1, 1, 2, 2, 2, 2, 2, 2, 1], 9, 'before'], 7), ('regression: position inverse map', [[1, 1, 1, 1, 2, 2], 5, 'before'], 1), ('line end', [[1, 1, 1], 3, 'after'], 0), ('line start before', [[1, 1, 0], 0, 'before'], 2), ('control layout', [[1], 0, 'before'], 1), ('control layout', [[1, 1, 0], 1, 'before'], 1)]]\nfor label, args, expected in fixtures[N - 1]:\n    check(label, solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"fd2deafab27671e4260a43557d4a15ec6c8868e28f147f5530ce9f45b1157847","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    def reorder(lv):\n        vis = list(range(len(lv)))\n        odd = [l for l in lv if l % 2 == 1]\n        if not odd:\n            return vis\n        for lev in range(max(lv), min(odd) - 1, -1):\n            i = 0\n            while i < len(vis):\n                if lv[vis[i]] >= lev:\n                    j = i\n                    while j < len(vis) and lv[vis[j]] >= lev:\n                        j += 1\n                    vis[i:j] = vis[i:j][::-1]\n                    i = j\n                else:\n                    i += 1\n        return vis\n    \n    levels, k, affinity = x\n    n = len(levels)\n    if n == 0:\n        return 0\n    vis = reorder(levels)\n    pos = [0] * n\n    for v, i in enumerate(vis):\n        pos[v] = i\n    if affinity == 'after' and k < n or k == 0:\n        j = k\n        leading = True\n    else:\n        j = k - 1\n        leading = False\n    rtl = levels[j] % 2 == 1\n    if leading:\n        return pos[j] + 1 if rtl else pos[j]\n    return pos[j] if rtl else pos[j] + 1\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: position inverse map', [[2, 2, 2, 4, 4, 4, 4, 1, 1], 7, 'before'], 9), ('regression: position inverse map', [[2, 2, 2, 2, 2, 2, 2, 1], 2, 'after'], 3), ('regression: position inverse map', [[2, 2, 1, 1], 0, 'after'], 2), ('regression: position inverse map', [[1, 2, 2], 1, 'after'], 0), ('caret at direction boundary', [[0, 0, 1, 1], 2, 'before'], 2), ('line start before', [[1, 1, 0], 0, 'before'], 2), ('control layout', [[3, 0, 0, 0, 2, 2, 2], 3, 'after'], 3), ('control layout', [[4], 1, 'before'], 1)], [('regression: position inverse map', [[2, 2, 2, 2, 2, 2, 2, 2, 1], 6, 'after'], 7), ('regression: position inverse map', [[1, 1, 1, 1, 1, 2, 2, 2, 2, 1], 6, 'before'], 2), ('partial-repair probe', [[0, 0, 0, 3, 1, 1, 1, 1, 1, 1], 5, 'before'], 8), ('partial-repair probe', [[1, 1, 0, 0, 0, 0, 0, 0], 5, 'before'], 5), ('caret at direction boundary', [[0, 0, 1, 1], 2, 'before'], 2), ('line end', [[1, 1, 1], 3, 'after'], 0), ('control layout', [[3], 1, 'before'], 0), ('control layout', [[1], 1, 'before'], 0)], [('regression: position inverse map', [[2, 2, 2, 2, 2, 3, 3, 2, 1], 0, 'before'], 1), ('regression: position inverse map', [[3, 3, 2, 2, 2, 2, 2, 2, 1, 1], 7, 'after'], 9), ('partial-repair probe', [[2, 2, 2, 2, 4, 2], 4, 'before'], 4), ('partial-repair probe', [[1, 1, 1, 1, 0, 0, 0, 0, 0, 2], 2, 'after'], 2), ('caret at direction boundary', [[0, 0, 1, 1], 2, 'before'], 2), ('same boundary after', [[0, 0, 1, 1], 2, 'after'], 4), ('control layout', [[1, 2, 1, 1, 3, 3, 3], 3, 'after'], 4), ('control layout', [[3], 1, 'before'], 0)], [('regression: position inverse map', [[1, 1, 1, 1, 2, 2], 5, 'before'], 1), ('regression: position inverse map', [[2, 2, 1, 1, 1, 1, 2, 2, 2], 2, 'after'], 7), ('partial-repair probe', [[3, 3, 3, 0, 0, 0, 3], 5, 'after'], 5), ('partial-repair probe', [[3, 3, 3, 3, 3, 3, 3], 0, 'before'], 7), ('line end', [[1, 1, 1], 3, 'after'], 0), ('line start before', [[1, 1, 0], 0, 'before'], 2), ('control layout', [[1], 0, 'before'], 1), ('control layout', [[2, 2, 1, 1, 1], 3, 'before'], 2)], [('regression: position inverse map', [[4, 4, 3, 3, 3, 3, 2, 2, 2], 2, 'before'], 6), ('regression: position inverse map', [[2, 2, 1, 1], 0, 'after'], 2), ('regression: position inverse map', [[1, 1, 1, 2, 2, 2, 2, 2, 2, 1], 9, 'before'], 7), ('regression: position inverse map', [[1, 1, 1, 1, 2, 2], 5, 'before'], 1), ('line end', [[1, 1, 1], 3, 'after'], 0), ('line start before', [[1, 1, 0], 0, 'before'], 2), ('control layout', [[1], 0, 'before'], 1), ('control layout', [[1, 1, 0], 1, 'before'], 1)]]\nfor label, args, expected in fixtures[N - 1]:\n    check(label, solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"fixed":{"sha256":"d318d36ef5ebba4fd836f314caba0646020b6224154171bdb9d15131b3646422","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    def reorder(lv):\n        vis = list(range(len(lv)))\n        odd = [l for l in lv if l % 2 == 1]\n        if not odd:\n            return vis\n        for lev in range(max(lv), min(odd) - 1, -1):\n            i = 0\n            while i < len(vis):\n                if lv[vis[i]] >= lev:\n                    j = i\n                    while j < len(vis) and lv[vis[j]] >= lev:\n                        j += 1\n                    vis[i:j] = vis[i:j][::-1]\n                    i = j\n                else:\n                    i += 1\n        return vis\n    \n    levels, k, affinity = x\n    n = len(levels)\n    if n == 0:\n        return 0\n    vis = reorder(levels)\n    pos = [0] * n\n    for v, i in enumerate(vis):\n        pos[i] = v\n    if affinity == 'after' and k < n or k == 0:\n        j = k\n        leading = True\n    else:\n        j = k - 1\n        leading = False\n    rtl = levels[j] % 2 == 1\n    if leading:\n        return pos[j] + 1 if rtl else pos[j]\n    return pos[j] if rtl else pos[j] + 1\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: position inverse map', [[2, 2, 2, 4, 4, 4, 4, 1, 1], 7, 'before'], 9), ('regression: position inverse map', [[2, 2, 2, 2, 2, 2, 2, 1], 2, 'after'], 3), ('regression: position inverse map', [[2, 2, 1, 1], 0, 'after'], 2), ('regression: position inverse map', [[1, 2, 2], 1, 'after'], 0), ('caret at direction boundary', [[0, 0, 1, 1], 2, 'before'], 2), ('line start before', [[1, 1, 0], 0, 'before'], 2), ('control layout', [[3, 0, 0, 0, 2, 2, 2], 3, 'after'], 3), ('control layout', [[4], 1, 'before'], 1)], [('regression: position inverse map', [[2, 2, 2, 2, 2, 2, 2, 2, 1], 6, 'after'], 7), ('regression: position inverse map', [[1, 1, 1, 1, 1, 2, 2, 2, 2, 1], 6, 'before'], 2), ('partial-repair probe', [[0, 0, 0, 3, 1, 1, 1, 1, 1, 1], 5, 'before'], 8), ('partial-repair probe', [[1, 1, 0, 0, 0, 0, 0, 0], 5, 'before'], 5), ('caret at direction boundary', [[0, 0, 1, 1], 2, 'before'], 2), ('line end', [[1, 1, 1], 3, 'after'], 0), ('control layout', [[3], 1, 'before'], 0), ('control layout', [[1], 1, 'before'], 0)], [('regression: position inverse map', [[2, 2, 2, 2, 2, 3, 3, 2, 1], 0, 'before'], 1), ('regression: position inverse map', [[3, 3, 2, 2, 2, 2, 2, 2, 1, 1], 7, 'after'], 9), ('partial-repair probe', [[2, 2, 2, 2, 4, 2], 4, 'before'], 4), ('partial-repair probe', [[1, 1, 1, 1, 0, 0, 0, 0, 0, 2], 2, 'after'], 2), ('caret at direction boundary', [[0, 0, 1, 1], 2, 'before'], 2), ('same boundary after', [[0, 0, 1, 1], 2, 'after'], 4), ('control layout', [[1, 2, 1, 1, 3, 3, 3], 3, 'after'], 4), ('control layout', [[3], 1, 'before'], 0)], [('regression: position inverse map', [[1, 1, 1, 1, 2, 2], 5, 'before'], 1), ('regression: position inverse map', [[2, 2, 1, 1, 1, 1, 2, 2, 2], 2, 'after'], 7), ('partial-repair probe', [[3, 3, 3, 0, 0, 0, 3], 5, 'after'], 5), ('partial-repair probe', [[3, 3, 3, 3, 3, 3, 3], 0, 'before'], 7), ('line end', [[1, 1, 1], 3, 'after'], 0), ('line start before', [[1, 1, 0], 0, 'before'], 2), ('control layout', [[1], 0, 'before'], 1), ('control layout', [[2, 2, 1, 1, 1], 3, 'before'], 2)], [('regression: position inverse map', [[4, 4, 3, 3, 3, 3, 2, 2, 2], 2, 'before'], 6), ('regression: position inverse map', [[2, 2, 1, 1], 0, 'after'], 2), ('regression: position inverse map', [[1, 1, 1, 2, 2, 2, 2, 2, 2, 1], 9, 'before'], 7), ('regression: position inverse map', [[1, 1, 1, 1, 2, 2], 5, 'before'], 1), ('line end', [[1, 1, 1], 3, 'after'], 0), ('line start before', [[1, 1, 0], 0, 'before'], 2), ('control layout', [[1], 0, 'before'], 1), ('control layout', [[1, 1, 0], 1, 'before'], 1)]]\nfor label, args, expected in fixtures[N - 1]:\n    check(label, solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"A deterministic toy bidi model over stipulated class labels and integer levels; it is inspired by, but does not claim conformance to, any published algorithm. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-bidirectional-text-layout-caret-position-position-inverse-map","generated_at":"2026-09-29T14:49:55.720736+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Mixed right-to-left and left-to-right text must resolve levels and visual order exactly, or words, numbers and carets land in the wrong place.","repair":"Map each logical index to its visual slot.","root_cause":"The inverse map is filled as pos[v] = i, which is just the visual order again.","sha256":"73df4464c2c2381ee662fcdb9f9db5f2568d306f06f33132acada9b1d0240da2","title":"Caret visual position: position inverse map · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.293,"exit_code":1,"observations":[{"actual":1,"check":"regression: position inverse map","expected":9,"passed":false},{"actual":4,"check":"regression: position inverse map","expected":3,"passed":false},{"actual":1,"check":"regression: position inverse map","expected":2,"passed":false},{"actual":2,"check":"regression: position inverse map","expected":0,"passed":false},{"actual":3,"check":"caret at direction boundary","expected":2,"passed":false},{"actual":2,"check":"line start before","expected":2,"passed":true},{"actual":3,"check":"control layout","expected":3,"passed":true},{"actual":1,"check":"control layout","expected":1,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: position inverse map\", \"actual\": 1, \"expected\": 9, \"passed\": false}, {\"check\": \"regression: position inverse map\", \"actual\": 4, \"expected\": 3, \"passed\": false}, {\"check\": \"regression: position inverse map\", \"actual\": 1, \"expected\": 2, \"passed\": false}, {\"check\": \"regression: position inverse map\", \"actual\": 2, \"expected\": 0, \"passed\": false}, {\"check\": \"caret at direction boundary\", \"actual\": 3, \"expected\": 2, \"passed\": false}, {\"check\": \"line start before\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"control layout\", \"actual\": 3, \"expected\": 3, \"passed\": true}, {\"check\": \"control layout\", \"actual\": 1, \"expected\": 1, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.896,"exit_code":1,"observations":[{"actual":5,"check":"regression: position inverse map","expected":9,"passed":false},{"actual":1,"check":"regression: position inverse map","expected":3,"passed":false},{"actual":3,"check":"regression: position inverse map","expected":2,"passed":false},{"actual":2,"check":"regression: position inverse map","expected":0,"passed":false},{"actual":2,"check":"caret at direction boundary","expected":2,"passed":true},{"actual":2,"check":"line start before","expected":2,"passed":true},{"actual":3,"check":"control layout","expected":3,"passed":true},{"actual":1,"check":"control layout","expected":1,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: position inverse map\", \"actual\": 5, \"expected\": 9, \"passed\": false}, {\"check\": \"regression: position inverse map\", \"actual\": 1, \"expected\": 3, \"passed\": false}, {\"check\": \"regression: position inverse map\", \"actual\": 3, \"expected\": 2, \"passed\": false}, {\"check\": \"regression: position inverse map\", \"actual\": 2, \"expected\": 0, \"passed\": false}, {\"check\": \"caret at direction boundary\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"line start before\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"control layout\", \"actual\": 3, \"expected\": 3, \"passed\": true}, {\"check\": \"control layout\", \"actual\": 1, \"expected\": 1, \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.575,"exit_code":0,"observations":[{"actual":9,"check":"regression: position inverse map","expected":9,"passed":true},{"actual":3,"check":"regression: position inverse map","expected":3,"passed":true},{"actual":2,"check":"regression: position inverse map","expected":2,"passed":true},{"actual":0,"check":"regression: position inverse map","expected":0,"passed":true},{"actual":2,"check":"caret at direction boundary","expected":2,"passed":true},{"actual":2,"check":"line start before","expected":2,"passed":true},{"actual":3,"check":"control layout","expected":3,"passed":true},{"actual":1,"check":"control layout","expected":1,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: position inverse map\", \"actual\": 9, \"expected\": 9, \"passed\": true}, {\"check\": \"regression: position inverse map\", \"actual\": 3, \"expected\": 3, \"passed\": true}, {\"check\": \"regression: position inverse map\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"regression: position inverse map\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"caret at direction boundary\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"line start before\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"control layout\", \"actual\": 3, \"expected\": 3, \"passed\": true}, {\"check\": \"control layout\", \"actual\": 1, \"expected\": 1, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}