Seven More Languages in Seven Weeks （读书笔记）：Factor

Factor

1. IN: scratchpad 20 9 * 5.0 / 32 + .
2. Booleans：t/f
3. Sequences：{ { "one" 1 } { "two" 2 } { "three" 3 } { "four" 4 } } //注意空格
4. Quotations（匿名函数）：[ 42 + ]
   1. call
5. 条件语句
   1. IN: scratchpad 10 0 > [ "pos" ] [ "neg" ] if .
   2. 或 IN: scratchpad 10 0 > "pos" "neg" ? .
6. Stack Shuffling
   1. dup, drop, nip, swap, over, rot, pick
7. Higher-Order Words with Combinators
   1. IN: scratchpad 44.50 [ 0.05 * ] [ 0.09975 * ] bi //见鬼
      1. bi*
      2. bi@
      3. tri tri* tri@
8. Vocabularies
   1. IN: scratchpad USE: present
   2. IN: scratchpad SYMBOL: tax-rate //What the Fuck!
   3.  : greeting ( name -- greeting ) "Hello, " swap append ; //定义一个库函数？IN: examples.greeter
   4.  : hello-world ( -- ) "world" greeting print ; //USE: examples.greeter
9. Tuples
   1. TUPLE: cart-item name price quantity ; //？类型没有声明
      1. price>>（读）
      2. >>price（写）
      3. change-price
   2. "Seven Languages Book" 25.00 1 cart-item boa //By Order of Arguments
10. 标准库（字典）：略
11. IN: scratchpad "demos" run