在福斯中，'expect'读多少个字符？

Question

Forth-83规范对expect一词的定义如下:

      EXPECT       addr +n --                    M,83                 
           Receive characters and store each into memory.  The transfer
           begins at addr proceeding towards higher addresses one byte
           per character until either a "return" is received or until
           +n characters have been transferred.  No more than +n
           characters will be stored.  The "return" is not stored into
           memory.  No characters are received or transferred if +n is
           zero.  All characters actually received and stored into
           memory will be displayed, with the "return" displaying as a
           space.

因此，它读取到但不包括RETURN或EOL。

但是没有结束符，也没有返回所读的字符数，我怎么知道字符串在哪里结束?

Leo Brodie提到了一个词accept，它的作用非常相似，它的签名是( addr +n -- +m )。它会返回读取的字符数，这是我所期望的。但规范中没有。

Answer 1

标准还定义了SPAN，它告诉您所读取的字符数。

还请注意，在新标准中此函数已废弃，请使用ACCEPT代替。