oeiuwq.com
An Algebraic Effect System for Golang.
Stop stores continuation
+32
-13
+1
-1
abort/result.go
+1
-1
abort/result.go
···
13
13
var err Result[V, E]
14
14
var abortFn AbortFn[E] = func(e E) fx.FxNil {
15
15
err = failure[V](e)
16
-
return fx.Stop[fx.Nil, fx.Nil]()
16
+
return fx.Halt[fx.Nil, fx.Nil]()
17
17
}
18
18
succeeded := fx.Map(fx.ProvideLeft(e, abortFn), success[V, E])
19
19
failed := func() fx.FxPure[Result[V, E]] { return fx.Pure(err) }
+31
-12
fx.go
+31
-12
fx.go
···
3
3
type Fx[S, V any] struct {
4
4
imm func() V
5
5
sus func(S) Fx[S, V]
6
-
stp func()
6
+
stp func(any) Fx[S, V]
7
7
}
8
8
9
9
type FxPure[V any] = Fx[Nil, V]
···
29
29
30
30
func Ctx[V any]() Fx[V, V] { return Func(identity[V]) }
31
31
32
-
func Stop[S, V any]() Fx[S, V] { return Fx[S, V]{stp: func() {}} }
32
+
// An stopped effect that panics if restarted
33
+
func Halt[S, V any]() Fx[S, V] {
34
+
return Stop(func(x any) Fx[S, V] {
35
+
panic("tried to restart halted effect. try using fx.Replace instead")
36
+
})
37
+
}
38
+
39
+
func Stop[S, V any](f func(any) Fx[S, V]) Fx[S, V] { return Fx[S, V]{stp: f} }
33
40
34
41
// Replace with y if x is already stopped. Otherwise x continues.
35
42
func Replace[S, V any](y func() Fx[S, V]) func(Fx[S, V]) Fx[S, V] {
···
48
55
func Cont[T, U, S, V any](cmap func(T) S, fmap func(V) Fx[T, U]) func(Fx[S, V]) Fx[T, U] {
49
56
return func(e Fx[S, V]) Fx[T, U] {
50
57
if e.stp != nil {
51
-
return Stop[T, U]()
58
+
return Stop(func(x any) Fx[T, U] {
59
+
return Cont(cmap, fmap)(e.stp(x))
60
+
})
52
61
}
53
62
if e.imm != nil {
54
63
return fmap(e.imm())
···
80
89
func ContraMap[V, S, R any](f func(R) S) func(Fx[S, V]) Fx[R, V] {
81
90
return func(e Fx[S, V]) Fx[R, V] {
82
91
if e.stp != nil {
83
-
return Stop[R, V]()
92
+
return Stop(func(x any) Fx[R, V] {
93
+
return ContraMap[V](f)(e.stp(x))
94
+
})
84
95
}
85
96
if e.imm != nil {
86
97
return Const[R](e.imm())
···
161
172
162
173
func ProvideLeft[A, B, V any](e Fx[And[A, B], V], a A) Fx[B, V] {
163
174
if e.stp != nil {
164
-
return Stop[B, V]()
175
+
return Stop(func(x any) Fx[B, V] {
176
+
return ProvideLeft(e.stp(x), a)
177
+
})
165
178
}
166
179
if e.imm != nil {
167
180
return Const[B](e.imm())
168
181
}
169
182
return Pending(func(b B) Fx[B, V] {
170
183
var ab And[A, B] = func() (A, B) { return a, b }
171
-
for {
172
-
e = e.sus(ab)
173
-
if e.stp != nil {
174
-
return Stop[B, V]()
175
-
}
176
-
if e.imm != nil {
177
-
return Const[B](e.imm())
184
+
var loop func(e Fx[And[A, B], V]) Fx[B, V]
185
+
loop = func(e Fx[And[A, B], V]) Fx[B, V] {
186
+
for {
187
+
e = e.sus(ab)
188
+
if e.stp != nil {
189
+
return Stop(func(x any) Fx[B, V] {
190
+
return loop(e.stp(x))
191
+
})
192
+
}
193
+
if e.imm != nil {
194
+
return Const[B](e.imm())
195
+
}
178
196
}
179
197
}
198
+
return loop(e)
180
199
})
181
200
}
182
201