1{2 "family": "hierarchy",3 "about": "children() in its STABLE order, and the parent link back. Order is contractual: the plan emits children in it, the palette indexes into it, and the conformance suites in both lanes compare the result positionally.",4 "cases": [5 {6 "name": "geohash-children-of-m",7 "ground": "test/square-1024",8 "system": "geohash",9 "call": "children",10 "args": [11 "m"12 ],13 "expect": [14 "m0",15 "m1",16 "m2",17 "m3",18 "m4",19 "m5",20 "m6",21 "m7",22 "m8",23 "m9",24 "mb",25 "mc",26 "md",27 "me",28 "mf",29 "mg",30 "mh",31 "mj",32 "mk",33 "mm",34 "mn",35 "mp",36 "mq",37 "mr",38 "ms",39 "mt",40 "mu",41 "mv",42 "mw",43 "mx",44 "my",45 "mz"46 ]47 },48 {49 "name": "geohash-children-of-the-root",50 "ground": "test/square-1024",51 "system": "geohash",52 "call": "children",53 "args": [54 ""55 ],56 "expect": [57 "0",58 "1",59 "2",60 "3",61 "4",62 "5",63 "6",64 "7",65 "8",66 "9",67 "b",68 "c",69 "d",70 "e",71 "f",72 "g",73 "h",74 "j",75 "k",76 "m",77 "n",78 "p",79 "q",80 "r",81 "s",82 "t",83 "u",84 "v",85 "w",86 "x",87 "y",88 "z"89 ]90 },91 {92 "name": "s2-faces",93 "ground": "test/sphere-8192x4096",94 "system": "s2",95 "call": "children",96 "args": [97 ""98 ],99 "expect": [100 "1",101 "3",102 "5",103 "7",104 "9",105 "b"106 ],107 "note": "The six faces of the cube, in face order. This is the root's child list.",108 "handDerived": true109 },110 {111 "name": "s2-children-of-47a1cb",112 "ground": "test/sphere-8192x4096",113 "system": "s2",114 "call": "children",115 "args": [116 "47a1cb"117 ],118 "expect": [119 "47a1ca4",120 "47a1cac",121 "47a1cb4",122 "47a1cbc"123 ]124 },125 {126 "name": "s2-parent-of-47a1ca4",127 "ground": "test/sphere-8192x4096",128 "system": "s2",129 "call": "parent",130 "args": [131 "47a1ca4"132 ],133 "expect": "47a1cb",134 "handDerived": true135 },136 {137 "name": "s2-child-index-of-47a1ca4",138 "ground": "test/sphere-8192x4096",139 "system": "s2",140 "call": "childIndex",141 "args": [142 "47a1ca4"143 ],144 "expect": 0145 },146 {147 "name": "s2-parent-of-47a1cac",148 "ground": "test/sphere-8192x4096",149 "system": "s2",150 "call": "parent",151 "args": [152 "47a1cac"153 ],154 "expect": "47a1cb",155 "handDerived": true156 },157 {158 "name": "s2-child-index-of-47a1cac",159 "ground": "test/sphere-8192x4096",160 "system": "s2",161 "call": "childIndex",162 "args": [163 "47a1cac"164 ],165 "expect": 1166 },167 {168 "name": "s2-parent-of-47a1cb4",169 "ground": "test/sphere-8192x4096",170 "system": "s2",171 "call": "parent",172 "args": [173 "47a1cb4"174 ],175 "expect": "47a1cb",176 "handDerived": true177 },178 {179 "name": "s2-child-index-of-47a1cb4",180 "ground": "test/sphere-8192x4096",181 "system": "s2",182 "call": "childIndex",183 "args": [184 "47a1cb4"185 ],186 "expect": 2187 },188 {189 "name": "s2-parent-of-47a1cbc",190 "ground": "test/sphere-8192x4096",191 "system": "s2",192 "call": "parent",193 "args": [194 "47a1cbc"195 ],196 "expect": "47a1cb",197 "handDerived": true198 },199 {200 "name": "s2-child-index-of-47a1cbc",201 "ground": "test/sphere-8192x4096",202 "system": "s2",203 "call": "childIndex",204 "args": [205 "47a1cbc"206 ],207 "expect": 3208 },209 {210 "name": "s2-children-of-a-face",211 "ground": "test/sphere-8192x4096",212 "system": "s2",213 "call": "children",214 "args": [215 "5"216 ],217 "expect": [218 "44",219 "4c",220 "54",221 "5c"222 ],223 "note": "The north-polar face's four children — the ids that do not refine by appending."224 },225 {226 "name": "real-children-of-the-root-are-the-window",227 "ground": "bend-or/2026-08-02/0",228 "system": "geohash",229 "call": "children",230 "args": [231 ""232 ],233 "expect": [234 "9rce",235 "9rcg",236 "9rcd",237 "9rcf",238 "9rc9",239 "9rcc"240 ],241 "note": "The root plan: the six depth-4 cells the window intersects (columns 166-167, rows 761-763 of the 0.3515625 x 0.17578125 degree grid), in reading order - north to south, west to east. Cells are the planet's; the PLAN is the window's.",242 "handDerived": true243 },244 {245 "name": "real-parent-of-a-base-cell-is-the-root",246 "ground": "bend-or/2026-08-02/0",247 "system": "geohash",248 "call": "parent",249 "args": [250 "9rcd"251 ],252 "expect": "",253 "handDerived": true254 },255 {256 "name": "real-parent-one-layer-down",257 "ground": "bend-or/2026-08-02/0",258 "system": "geohash",259 "call": "parent",260 "args": [261 "9rcdx"262 ],263 "expect": "9rcd",264 "handDerived": true265 },266 {267 "name": "real-childindex-is-the-window-position",268 "ground": "bend-or/2026-08-02/0",269 "system": "geohash",270 "call": "childIndex",271 "args": [272 "9rcd"273 ],274 "expect": 2,275 "note": "Position among the window's own cells in reading order, not the last character's alphabet ordinal: with absent siblings filtered out, the ordinal would leave holes in the palette walk.",276 "handDerived": true277 }278 ]279}