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ee7cd585 JM |
1 | Imports System |
2 | Imports System.IO | |
3 | Imports System.Collections.Generic | |
4 | Imports Mal | |
5 | Imports MalVal = Mal.types.MalVal | |
6 | Imports MalInt = Mal.types.MalInt | |
7 | Imports MalSymbol = Mal.types.MalSymbol | |
8 | Imports MalList = Mal.types.MalList | |
9 | Imports MalVector = Mal.types.MalVector | |
10 | Imports MalHashMap = Mal.types.MalHashMap | |
11 | Imports MalFunc = Mal.types.MalFunc | |
12 | Imports MalEnv = Mal.env.Env | |
13 | ||
14 | Namespace Mal | |
aaba2493 | 15 | Class step3_env |
ee7cd585 JM |
16 | ' read |
17 | Shared Function READ(str As String) As MalVal | |
18 | Return reader.read_str(str) | |
19 | End Function | |
20 | ||
21 | ' eval | |
22 | Shared Function eval_ast(ast As MalVal, env As MalEnv) As MalVal | |
23 | If TypeOf ast Is MalSymbol Then | |
24 | Dim sym As MalSymbol = DirectCast(ast, MalSymbol) | |
25 | return env.do_get(sym.getName()) | |
26 | Else If TypeOf ast Is MalList Then | |
27 | Dim old_lst As MalList = DirectCast(ast, MalList) | |
28 | Dim new_lst As MalList | |
29 | If ast.list_Q() Then | |
30 | new_lst = New MalList | |
31 | Else | |
32 | new_lst = DirectCast(New MalVector, MalList) | |
33 | End If | |
34 | Dim mv As MalVal | |
35 | For Each mv in old_lst.getValue() | |
36 | new_lst.conj_BANG(EVAL(mv, env)) | |
37 | Next | |
38 | return new_lst | |
39 | Else If TypeOf ast Is MalHashMap Then | |
40 | Dim new_dict As New Dictionary(Of String, MalVal) | |
41 | Dim entry As KeyValuePair(Of String, MalVal) | |
42 | For Each entry in DirectCast(ast,MalHashMap).getValue() | |
43 | new_dict.Add(entry.Key, EVAL(DirectCast(entry.Value,MalVal), env)) | |
44 | Next | |
45 | return New MalHashMap(new_dict) | |
46 | Else | |
47 | return ast | |
48 | End If | |
49 | return ast | |
50 | End Function | |
51 | ||
52 | Shared Function EVAL(orig_ast As MalVal, env As MalEnv) As MalVal | |
53 | 'Console.WriteLine("EVAL: {0}", printer._pr_str(orig_ast, true)) | |
54 | If not orig_ast.list_Q() Then | |
55 | return eval_ast(orig_ast, env) | |
56 | End If | |
57 | ||
58 | ' apply list | |
59 | Dim ast As MalList = DirectCast(orig_ast, MalList) | |
60 | If ast.size() = 0 Then | |
61 | return ast | |
62 | End If | |
63 | Dim a0 As MalVal = ast(0) | |
64 | Select DirectCast(a0,MalSymbol).getName() | |
65 | Case "def!" | |
66 | Dim a1 As MalVal = ast(1) | |
67 | Dim a2 As MalVal = ast(2) | |
68 | Dim res As MalVal = EVAL(a2, env) | |
69 | env.do_set(DirectCast(a1,MalSymbol).getName(), res) | |
70 | return res | |
71 | Case "let*" | |
72 | Dim a1 As MalVal = ast(1) | |
73 | Dim a2 As MalVal = ast(2) | |
74 | Dim key As MalSymbol | |
75 | Dim val as MalVal | |
76 | Dim let_env As new MalEnv(env) | |
77 | For i As Integer = 0 To (DirectCast(a1,MalList)).size()-1 Step 2 | |
78 | key = DirectCast(DirectCast(a1,MalList)(i),MalSymbol) | |
79 | val = DirectCast(a1,MalList)(i+1) | |
80 | let_env.do_set(key.getName(), EVAL(val, let_env)) | |
81 | Next | |
82 | return EVAL(a2, let_env) | |
83 | Case Else | |
84 | Dim el As MalList = DirectCast(eval_ast(ast, env), MalList) | |
85 | Dim f As MalFunc = DirectCast(el(0), MalFunc) | |
86 | Return f.apply(el.rest()) | |
87 | End Select | |
88 | End Function | |
89 | ||
90 | ||
91 | Shared Function PRINT(exp As MalVal) As String | |
92 | return printer._pr_str(exp, TRUE) | |
93 | End Function | |
94 | ||
95 | ' repl | |
96 | Shared repl_env As MalEnv | |
97 | ||
98 | Shared Function REP(str As String) As String | |
99 | Return PRINT(EVAL(READ(str), repl_env)) | |
100 | End Function | |
101 | ||
102 | Shared Function add(a As MalList) As MalVal | |
103 | Return DirectCast(a.Item(0),MalInt) + DirectCast(a.Item(1),MalInt) | |
104 | End Function | |
105 | ||
106 | Shared Function minus(a As MalList) As MalVal | |
107 | Return DirectCast(a.Item(0),MalInt) - DirectCast(a.Item(1),MalInt) | |
108 | End Function | |
109 | ||
110 | Shared Function mult(a As MalList) As MalVal | |
111 | Return DirectCast(a.Item(0),MalInt) * DirectCast(a.Item(1),MalInt) | |
112 | End Function | |
113 | ||
114 | Shared Function div(a As MalList) As MalVal | |
115 | Return DirectCast(a.Item(0),MalInt) / DirectCast(a.Item(1),MalInt) | |
116 | End Function | |
117 | ||
118 | Shared Function Main As Integer | |
119 | Dim args As String() = Environment.GetCommandLineArgs() | |
120 | ||
121 | repl_env = New MalEnv(Nothing) | |
122 | repl_env.do_set("+", New MalFunc(AddressOf add)) | |
123 | repl_env.do_set("-", New MalFunc(AddressOf minus)) | |
124 | repl_env.do_set("*", New MalFunc(AddressOf mult)) | |
125 | repl_env.do_set("/", New MalFunc(AddressOf div)) | |
126 | ||
127 | ||
128 | If args.Length > 1 AndAlso args(1) = "--raw" Then | |
129 | Mal.readline.SetMode(Mal.readline.Modes.Raw) | |
130 | End If | |
131 | ||
132 | ' repl loop | |
133 | Dim line As String | |
134 | Do | |
135 | Try | |
136 | line = Mal.readline.Readline("user> ") | |
137 | If line is Nothing Then | |
138 | Exit Do | |
139 | End If | |
140 | If line = "" Then | |
141 | Continue Do | |
142 | End If | |
143 | Catch e As IOException | |
144 | Console.WriteLine("IOException: " & e.Message) | |
145 | End Try | |
146 | Try | |
147 | Console.WriteLine(REP(line)) | |
148 | Catch e as Exception | |
149 | Console.WriteLine("Error: " & e.Message) | |
150 | Console.WriteLine(e.StackTrace) | |
151 | Continue Do | |
152 | End Try | |
153 | Loop While True | |
154 | End function | |
aaba2493 | 155 | End Class |
ee7cd585 | 156 | End Namespace |