奇怪的＆＃34;字没有上下文＆＃34; rebol程序中的错误

Question

以下是来自控制台的错误：

>> ? column
COLUMN is a block of value: [Person 2 Date 3 Quantity 4 Size 5 ProductType 6 
LineItem  7 Deliver 8 FillStatus 9 Note 10 Time 11]
>> ? column/Size
COLUMN/SIZE is an integer of value: 5
>> ? a
A is a block of value: [column/Size]
>> reduce a
** Script Error: column word has no context
** Near: column/Size
>> ? b
B is a block of value: [column/Size]
>> reduce b
== [5]

为什么变量'a'不能正确减少？

Answer 1

我不知道你是如何定义column和a的，因为当我从控制台尝试它时，它可以工作：

>> column: [Person 2 Date 3 Quantity 4 Size 5 ProductType 6 LineItem  7 Deliver 8 FillStatus 9 Note 10 Time 11]
== [Person 2 Date 3 Quantity 4 Size 5 ProductType 6 LineItem 7 Deliver 8 FillStatus 9 Note 10 Time 11]

>> a: [column/size]
== [column/size]

>> reduce a
== [5]

无论如何，您可以尝试绑定a：

>> reduce bind a 'column
== [5]