Submatrix Ocaml

Question

let moja_matrika1 = [[1; 2]; [3; 4]];; 
let moja_matrika2 = [[4; 7; 8]; [3; 2; 1]];; 

let rec does_it_contain (lis1, lis2) = 
if (List.hd lis1 = []) then false 
else if (List.hd lis1 = lis2) then true 
else does_it_contain ((List.tl lis1), lis2);; 

let rec does_it (matrix, lis1) = 
if (matrix = []) then false 
else if does_it_contain (List.hd matrix, List.hd lis1) = true then true 
else does_it (List.tl matrix, lis1);; 

does_it (moja_matrika1, moja_matrika2);; 

我想检查一个矩阵是否是另一个矩阵的sbumatrix。但我必须使用类型列表。而且我不能使用任何定义的List函数。显然，我使用List hd，tl，但我会替换它。

当我尝试调用至少不理解的函数时出现错误。

does_it (moja_matrika1, moja_matrika2);; 
Error: This expression has type int list list 
     but an expression was expected of type 'a list list list 
     Type int is not compatible with type 'a list # 

请帮忙！

Answer 1

我想通了。

let rec does_it_contain (lis1, lis2) = 
    if rep lis1 = [] then false 
    else if rep lis2 = [] then false 
    else if ( glava lis1 = glava lis2) then true 
else does_it_contain (lis1, rep lis2);; 

let rec does_it (matrica, matrica1) = 
    if rep matrica = [] then false 
    else if rep matrica1 = [] then false 
    else if does_it_contain (glava matrica, glava matrica1) = true then true 
    else does_it (rep matrica, rep matrica1);; 


does_it(moja_matrika1, moja_matrika2);; 

rep是List.tl的替代品，glava是List.hd的替代品。

Answer 2

does_it_contain和does_it的签名是结构延续respectnot：

'a list list * 'a list -> bool 
    'a list list list * 'a list list -> bool 

他们都不是能够拿2矩阵作为参数（'a list和'a list list list像您期望的不是矩阵）

而且，你把你的函数的代码写成如C或者java一样：参数不能通过Ocaml的圆括号传递。括号用于元组 - 在这种情况下这没有用。