有了
Expected語法之后總是要實驗一下的。現(xiàn)在給出一個非完整函數(shù)eq的聲明，并用一個列表查找函數(shù)使用eq。已知代碼如下：
1 module main
2 import system
3 import sysutils
4 import list
5
6 func eq T :: T -> T -> bool expected
7
8 def exists e xs =
9 select xs of
10 case list x tail : if(eq e x) true (exists e tail)
11 case empty : false
12 end
13
14 def eq a b = iequ a b
15
16 def eq a b = fequ a b
17
18 def main score = if (flt score 60.0) "fail" "pass"
19
20 def ints = list 1 (list 2 (list 3 empty))
21 def floats = list 1.0 (list 2.0 (list 3.0 empty))
22 def chars = "vczh"
23
24 def main2 = exists 0 ints
25 def main3 = exists 0.0 floats
26 def main4 = exists 'a' chars
注意最后一行。由于exists在這里接受字符，但是不存在接受字符的eq，因此輸出錯誤：
1 生成符號表時發(fā)生錯誤
2 錯誤[1] 模塊：main 行號：10
3 信息：符號"eq"無法匹配到函數(shù)，類型：(system.char -> (system.char -> system.bool))。
如果我們把最后一行去掉，則會產(chǎn)生正確的結(jié)果。注意exists的兩個實例所對應的eq是不同的：
1 【Code Unit main】
2 module main::main
3 import list
4 import system
5 import sysutils
6 func eq T :: (<T> -> (<T> -> system.bool)) expected
7 func chars :: (system.list system.char) codefrom 7
8 func eq :: (system.int -> (system.int -> system.bool)) codefrom 2
9 func eq :: (system.float -> (system.float -> system.bool)) codefrom 3
10 func exists T1 :: (<T1> -> ((system.list <T1>) -> system.bool)) codefrom 1
11 func floats :: (system.list system.float) codefrom 6
12 func ints :: (system.list system.int) codefrom 5
13 func main :: (system.float -> (system.list system.char)) codefrom 4
14 func main2 :: system.bool codefrom 8
15 func main3 :: system.bool codefrom 9
16
17 【Assembly Unit main】
18
19 [Information]
20 Name : main
21 Function Count : 9
22 Slot Count : 10
23
24 [Function]
25 Function Name : chars
26 Unique Name : main::chars::#7
27 Owner Unit : main
28 Level : 0
29 External Command :
30 Instance : main::chars::#7::(system.list system.char)
31
32 [Function]
33 Function Name : eq
34 Unique Name : main::eq::#2
35 Owner Unit : main
36 Level : 0
37 External Command :
38 Instance : main::eq::#2::(system.int -> (system.int -> system.bool))
39
40 [Function]
41 Function Name : eq
42 Unique Name : main::eq::#3
43 Owner Unit : main
44 Level : 0
45 External Command :
46 Instance : main::eq::#3::(system.float -> (system.float -> system.bool))
47
48 [Function]
49 Function Name : exists
50 Unique Name : main::exists::#1
51 Owner Unit : main
52 Level : 0
53 External Command :
54 Instance : <NULL>
55
56 [Function]
57 Function Name : floats
58 Unique Name : main::floats::#6
59 Owner Unit : main
60 Level : 0
61 External Command :
62 Instance : main::floats::#6::(system.list system.float)
63
64 [Function]
65 Function Name : ints
66 Unique Name : main::ints::#5
67 Owner Unit : main
68 Level : 0
69 External Command :
70 Instance : main::ints::#5::(system.list system.int)
71
72 [Function]
73 Function Name : main2
74 Unique Name : main::main2::#8
75 Owner Unit : main
76 Level : 0
77 External Command :
78 Instance : main::main2::#8::system.bool
79
80 [Function]
81 Function Name : main3
82 Unique Name : main::main3::#9
83 Owner Unit : main
84 Level : 0
85 External Command :
86 Instance : main::main3::#9::system.bool
87
88 [Function]
89 Function Name : main
90 Unique Name : main::main::#4
91 Owner Unit : main
92 Level : 0
93 External Command :
94 Instance : main::main::#4::(system.float -> (system.list system.char))
95
96 [Slot Item]
97 Unique Name : main::chars::#7::(system.list system.char)
98 Parent Slot : <NULL>
99 Owner Function : main::chars::#7
100
101 [Slot Item]
102 Unique Name : main::eq::#2::(system.int -> (system.int -> system.bool))
103 Parent Slot : <NULL>
104 Owner Function : main::eq::#2
105 3 = system::iequ::$kernelfp::iequ::(system.int -> (system.int -> system.bool))
106
107 [Slot Item]
108 Unique Name : main::eq::#3::(system.float -> (system.float -> system.bool))
109 Parent Slot : <NULL>
110 Owner Function : main::eq::#3
111 4 = system::fequ::$kernelfp::fequ::(system.float -> (system.float -> system.bool))
112
113 [Slot Item]
114 Unique Name : main::exists::#1::(system.float -> ((system.list system.float) -> system.bool))
115 Parent Slot : <NULL>
116 Owner Function : main::exists::#1
117 0 = sysutils::if::#9::(system.bool -> (system.bool -> (system.bool -> system.bool)))
118 1 = main::eq::#3::(system.float -> (system.float -> system.bool))
119 2 = main::exists::#1::(system.float -> ((system.list system.float) -> system.bool))
120
121 [Slot Item]
122 Unique Name : main::exists::#1::(system.int -> ((system.list system.int) -> system.bool))
123 Parent Slot : <NULL>
124 Owner Function : main::exists::#1
125 0 = sysutils::if::#9::(system.bool -> (system.bool -> (system.bool -> system.bool)))
126 1 = main::eq::#2::(system.int -> (system.int -> system.bool))
127 2 = main::exists::#1::(system.int -> ((system.list system.int) -> system.bool))
128
129 [Slot Item]
130 Unique Name : main::floats::#6::(system.list system.float)
131 Parent Slot : <NULL>
132 Owner Function : main::floats::#6
133
134 [Slot Item]
135 Unique Name : main::ints::#5::(system.list system.int)
136 Parent Slot : <NULL>
137 Owner Function : main::ints::#5
138
139 [Slot Item]
140 Unique Name : main::main2::#8::system.bool
141 Parent Slot : <NULL>
142 Owner Function : main::main2::#8
143 7 = main::exists::#1::(system.int -> ((system.list system.int) -> system.bool))
144 8 = main::ints::#5::(system.list system.int)
145
146 [Slot Item]
147 Unique Name : main::main3::#9::system.bool
148 Parent Slot : <NULL>
149 Owner Function : main::main3::#9
150 9 = main::exists::#1::(system.float -> ((system.list system.float) -> system.bool))
151 10 = main::floats::#6::(system.list system.float)
152
153 [Slot Item]
154 Unique Name : main::main::#4::(system.float -> (system.list system.char))
155 Parent Slot : <NULL>
156 Owner Function : main::main::#4
157 5 = sysutils::if::#9::(system.bool -> ((system.list system.char) -> ((system.list system.char) -> (system.list system.char))))
158 6 = system::flt::$kernelfp::flt::(system.float -> (system.float -> system.bool))
posted on 2008-11-02 07:36
陳梓瀚(vczh) 閱讀(1516)
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