for-loop - 使用详细语法在 F# 嵌套 for 循环中编译错误

Question

我是 F# 的新手，但是当我使用详细语法将 for 循环放入另一个循环时，它不会编译：

#light "off"

let Multiple9x9 () = 
  for i in 1 .. 9 do
    printf "\n";
    for j in 1 .. 9 do
      let k = i * j;
      printf "%d x %d = %2d " i j k ;
    done;;
  done;;
Multiple9x9 ();;
printf "\n" ;;

我知道它可以与#light“on”一起使用：

let Multiple9x9 () = 
  for i in 1 .. 9 do
    printf "\n"
    for j in 1 .. 9 do
      let k = i * j
      printf "%d x %d = %2d " i j k
Multiple9x9 ()
printf "\n"

Answer 1

如果您要in在每次let绑定后使用所需的详细语法。此外，内循环中不需要;;after done：它使外循环不完整（切断外循环done）。

这是更正后的代码：

let Multiple9x9 () = 
  for i in 1 .. 9 do
    printf "\n";
    for j in 1 .. 9 do
      let k = i * j in
      printf "%d x %d = %2d " i j k;
    done;
  done;;
Multiple9x9 ();;
printf "\n" ;;