wolfram-mathematica - 请求代码审查和改进建议(是 : Question on making a function Listable )

Question

根据 acl 请求清理问题:

我有以下代码

AddGeometry[scg_, tfg_, geo_] := 

Module[{
i,
georec},

If[StringQ[geo[[2,1]]]&&StringMatchQ[geo[[2,1]],"GE"],   (* DIRTY, BWAH *)
    AddAsChild[scg, tfg, geo],
    (
    i=1;
    While[i<=Length[geo],
        georec=geo[[i]];
        AddGeometry[scg, tfg, georec];
        i++
    ]
    )
]

]

SetAttributes[AddGeometry, HoldAll];

geo_ 看起来像这样:

{
{4, {"GE", {"CU", {{0, 0, 0}, 4}}}, 5, 2}, 
{7, {"GE", {"CU", {{0, 3, 0}, 1}}}, 5, 2},
{12, {"GE", {"CU", {{0, 5, 0}, 2}}}, 5, 2},
}

它包含 1, 2, ... n 个类型的记录
{4, {"GE", {"CU", {{0, 0, 0}, 4}}}, 5, 2}

调用代码看起来像

c1 = NewCube[]

( c1 获得像 {4, {"GE", {"CU", {{0, 0, 0}, 4}}}, 5, 2} )等值。

AddGeometry[scg, tfg, c1]

或者当需要添加多个几何图形时:

AddGeometry[scg, tfg, {c1, c2, c3}]

上面的代码有效。

题:

有没有更简洁的方法(使用多态)来实现这个？

来自@acl:

AddGeometry[scg_, tfg_, geo_] := 
Module[{
    georec=geo}, 

    AddAsChild[scg, tfg, georec]

] /; MatchQ[geo, {_, {"GE", __}, __}];      

AddGeometry[scg_, tfg_, geo_] := 
Module[{},
    Map[AddGeometry[scg, tfg, #] & ,geo]
]

Answer 1

回应更新的问题，怎么样

 ClearAll[AddGeometry];
 SetAttributes[AddGeometry, HoldAll];

 AddGeometry[scg_, tfg_, geo_] := Module[{}, AddAsChild[scg, tfg, geo]] /; MatchQ[geo, {_, {"GE", __}, __}];

 AddGeometry[scg_, tfg_, geo_] := (AddGeometry[scg, tfg, #] & /@ geo)

我测试的

 c1 = {4, {"GE", {"CU", {{0, 0, 0}, 4}}}, 5, 2};
 g = {{4, {"GE", {"CU", {{0, 0, 0}, 4}}}, 5, 
2}, {7, {"GE", {"CU", {{0, 3, 0}, 1}}}, 5, 
2}, {12, {"GE", {"CU", {{0, 5, 0}, 2}}}, 5, 2}};

AddGeometry[scg, tfg, c1]
AddGeometry[scg, tfg, g]

这给了

AddAsChild[scg, tfg, {4, {"GE", {"CU", {{0, 0, 0}, 4}}}, 5, 2}]

和

 {AddAsChild[scg, tfg, {4, {"GE", {"CU", {{0, 0, 0}, 4}}}, 5, 2}], 
 AddAsChild[scg, tfg, {7, {"GE", {"CU", {{0, 3, 0}, 1}}}, 5, 2}], 
  AddAsChild[scg, tfg, {12, {"GE", {"CU", {{0, 5, 0}, 2}}}, 5, 2}]}

另外，如果 AddAsChild纯粹与副作用一起工作，可以使用 Scan而不是 Map避免得到 Null 的返回列表s(或将第二个定义修改为 AddGeometry[scg_, tfg_, geo_] := (AddGeometry[scg, tfg, #]; & /@ geo))。