-
Notifications
You must be signed in to change notification settings - Fork 0
/
casts.rkt
251 lines (244 loc) · 10 KB
/
casts.rkt
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
#lang racket
(require "utilities.rkt")
(provide make-cast apply-inject apply-project flat-type-eq?)
(define (make-cast e s t)
(verbose "make-cast " s t)
(cond [(equal? s t)
;; This is obervable because eq? doesn't dive through proxies,
;; but should it? -Jeremy
e]
[else
(match (list s t)
[`(Integer Integer) e]
[`(Boolean Boolean) e]
[`(Void Void) e]
[`(Nothing Nothing) e]
[`(Any Any) e]
[`(Any ,t2)
(match t2
[`(,ts ... -> ,rt)
(define any->any `(,@(for/list ([t ts]) 'Any) -> Any))
;; first project from (,ts ... -> ,rt) to (Any ... -> Any)
(define e^ (HasType (Project e any->any) any->any))
;; then cast from (Any ... -> Any) to (,ts ... -> ,rt)
(make-cast e^ any->any `(,@ts -> ,rt))]
[`(Vector ,ts ...)
(define vec-any `(Vector ,@(for/list ([t ts]) 'Any)))
;; first project to (Vector Any ...)
(define e^ (HasType (Project e vec-any) vec-any))
;; then cast from (Vector Any ...) to (Vector ,ts ...)
(make-cast e^ vec-any `(Vector ,@ts))]
[`(Vectorof ,t)
(define vec-any `(Vectorof Any))
;; first project to (Vectorof Any)
(define e^ (HasType (Project e vec-any) vec-any))
;; then cast from (Vectorof Any) to (Vectorof ,t)
(make-cast e^ vec-any `(Vectorof ,t))]
[else
(HasType (Project e t2) t2)])]
[`(,t1 Any)
(match t1
[`(,ts ... -> ,rt)
(define any->any `(,@(for/list ([t ts]) 'Any) -> Any))
;; first cast from (,ts ... -> ,rt) to (Any ... -> Any)
(define e^ (make-cast e `(,@ts -> ,rt) any->any))
;; then inject from (Any ... -> Any) to ANy
(HasType (Inject e^ any->any) 'Any)]
[`(Vector ,ts ...)
(define vec-any `(Vector ,@(for/list ([t ts]) 'Any)))
;; first cast (Vector ,ts ...) from (Vector Any ...)
(define e^ (make-cast e `(Vector ,@ts) vec-any))
;; then inject from (Vector Any ...) to Any
(HasType (Inject e^ vec-any) 'Any)]
[`(Vectorof ,t)
(define vec-any `(Vectorof Any))
;; first cast from (Vectorof ,t) to (Vectorof Any)
(define e^ (make-cast e `(Vectorof ,t) vec-any))
;; then inject from (Vectorof Any) to Any
(HasType (Inject e^ vec-any) 'Any)]
[else
(HasType (Inject e t1) 'Any)])]
[`((Vectorof ,t1) (Vectorof ,t2))
(let ([x (gensym 'x)])
(HasType (Prim
'vectorof-proxy
(list e
;; reading
(HasType
(Lambda `([,x : ,t1]) t2
(make-cast (HasType (Var x) t1) t1 t2))
`(,t1 -> ,t2))
;; writing
(HasType
(Lambda `([,x : ,t2]) t1
(make-cast (HasType (Var x) t2) t2 t1))
`(,t2 -> ,t1))
))
`(Vectorof ,t2)))]
[`((Vector ,ts1 ...) (Vector ,ts2 ...))
(let ([x (gensym 'x)])
(HasType
(Prim 'vector-proxy
(list e
;; reading
(HasType
(Prim 'vector
(for/list ([t1 ts1] [t2 ts2])
(HasType
(Lambda `([,x : ,t1]) t2
(make-cast (HasType (Var x) t1)
t1 t2))
`(,t1 -> ,t2))))
`(Vector _))
;; writing
(HasType
(Prim 'vector
(for/list ([t1 ts1] [t2 ts2])
(HasType
(Lambda `([,x : ,t2]) t1
(make-cast (HasType (Var x) t2)
t2 t1))
`(,t2 -> ,t1))))
`(Vector _))
))
`(Vector ,@ts2)))]
[`((,ts1 ... -> ,rt1) (,ts2 ... -> ,rt2))
(define xs (for/list ([t2 ts2]) (gensym 'x)))
(define params (for/list ([x xs] [t2 ts2]) `[,x : ,t2]))
(HasType (Lambda params rt2
(make-cast
(Apply e (for/list ([x xs]
[t1 ts1] [t2 ts2])
(make-cast
(HasType (Var x) t2) t2 t1)))
rt1 rt2))
`(,@ts2 -> ,rt2))]
[else
#f]
)]))
(define (apply-inject v tg)
`(tagged ,v ,tg))
;; Equality for flat types.
(define (flat-type-eq? t1 t2)
(match `(,t1 ,t2)
[`((Vectorof Any) (Vector ,t2s ...))
(for/and ([t2 t2s])
(eq? t2 'Any))]
[`((Vector ,t1s ...) (Vectorof Any))
(for/and ([t1 t1s])
(eq? t1 'Any))]
[else (equal? t1 t2)]))
(define (apply-project v ty2)
(define tag2 (any-tag ty2))
(match v
[`(tagged ,v1 ,tag1)
(cond [(eq? tag1 tag2)
(match ty2
[`(Vector ,ts ...)
(cond [(eq? (vector-length v1) (length ts))
v1]
[else
(error 'apply-project
"vector length ~a does not match length of target type ~a"
(vector-length v1) (length ts))])]
[`(,ts ... -> ,rt)
(match v1
[`(function ,xs ,body ,env)
(cond [(eq? (length xs) (length ts))
v1]
[else
(error 'apply-project
"function arity ~a does not match arity of target type ~a"
(length xs) (length ts))])]
[else (error 'apply-project "expected a function, not ~a" v1)])]
[else
v1])]
[else
(error 'apply-project "tag mismatch ~a != ~a" tag1 tag2)])]
[else
(error 'apply-project "expected tagged value, not ~a" v)]))
#;(define (apply-cast v s t)
(match (list s t)
[`(Integer Integer) v]
[`(Boolean Boolean) v]
[`(Void Void) v]
[`(Nothing Nothing) v]
[`(Any Any) v]
[`(Any ,t2)
(match t2
[`(,ts ... -> ,rt)
(define any->any `(,@(for/list ([t ts]) 'Any) -> Any))
;; first project from (,ts ... -> ,rt) to (Any ... -> Any)
(define v^ (apply-project v any->any))
;; then cast from (Any ... -> Any) to (,ts ... -> ,rt)
(apply-cast e^ any->any `(,@ts -> ,rt))]
[`(Vector ,ts ...)
(define vec-any `(Vector ,@(for/list ([t ts]) 'Any)))
;; first project to (Vector Any ...)
(define v^ (apply-project v vec-any))
;; then cast from (Vector Any ...) to (Vector ,ts ...)
(apply-cast v^ vec-any `(Vector ,@ts))]
[`(Vectorof ,t)
(define vec-any `(Vectorof Any))
;; first project to (Vectorof Any)
(define v^ (apply-project v vec-any))
;; then cast from (Vectorof Any) to (Vectorof ,t)
(apply-cast v^ vec-any `(Vectorof ,t))]
[else
(apply-project v t2)])]
[`(,t1 Any)
(match t1
[`(,ts ... -> ,rt)
(define any->any `(,@(for/list ([t ts]) 'Any) -> Any))
;; first cast from (,ts ... -> ,rt) to (Any ... -> Any)
(define v^ (apply-cast v `(,@ts -> ,rt) any->any))
;; then inject from (Any ... -> Any) to ANy
(apply-inject v^ any->any)]
[`(Vector ,ts ...)
(define vec-any `(Vector ,@(for/list ([t ts]) 'Any)))
;; first cast (Vector ,ts ...) from (Vector Any ...)
(define v^ (apply-cast v `(Vector ,@ts) vec-any))
;; then inject from (Vector Any ...) to Any
(apply-inject v^ vec-any)]
[`(Vectorof ,t)
(define vec-any `(Vectorof Any))
;; first cast from (Vectorof ,t) to (Vectorof Any)
(define v^ (apply-cast v `(Vectorof ,t) vec-any))
;; then inject from (Vectorof Any) to Any
(apply-inject v^ vec-any)]
[else
(apply-inject v t1)])]
[`((Vector ,ts1 ...) (Vector ,ts2 ...))
(let ([x (gensym 'x)])
`(vector-proxy
,v
;; reading
,@(for/list ([t1 ts1] [t2 ts2])
`(function: ([,x : ,t1]) : ,t2 () ,(make-cast x t1 t2)))
;; writing
,@(for/list ([t1 ts1] [t2 ts2])
`(function: ([,x : ,t2]) : ,t1 ,(make-cast x t2 t1)))
))]
[`((,ts1 ... -> ,rt1) (,ts2 ... -> ,rt2))
(define xs (for/list ([t2 ts2]) (gensym 'x)))
(define params (for/list ([x xs] [t2 ts2]) `[,x : ,t2]))
`(has-type (lambda: ,params : ,rt2
,(apply-cast
`(,e ,@(for/list ([x xs] [t1 ts1] [t2 ts2])
(apply-cast x t2 t1)))
rt1 rt2))
(,@ts2 -> ,rt2))]
[`((Vectorof ,t1) (Vectorof ,t2))
(let ([x (gensym 'x)])
`(vectorof-proxy
,e
;; reading
(has-type (lambda: ([,x : ,t1]) : ,t2 ,(apply-cast x t1 t2))
(,t1 -> ,t2))
;; writing
(has-type (lambda: ([,x : ,t2]) : ,t1 ,(apply-cast x t2 t1))
(,t2 -> ,t1))
))]
[else
#f]
))