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
|
package interpreter
import (
"fmt"
"usebox.net/micro-lang/ast"
"usebox.net/micro-lang/errors"
"usebox.net/micro-lang/tokens"
)
type Callable interface {
Name() string
String() string
Call(interp *Interpreter, args []any, loc tokens.Location) (any, error)
Type() *ast.Type
Params() []ast.Type
Ret() *ast.Type
}
var builtInFuncs = map[string]Callable{
"len": builtInLen{},
"println": builtInPrintln{},
"panic": builtInPanic{},
}
func BuiltInTypes() map[string]ast.Type {
types := map[string]ast.Type{}
for k, v := range builtInFuncs {
types[k] = *v.Type()
}
return types
}
type builtInLen struct{}
func (n builtInLen) Name() string {
return "'len'"
}
func (n builtInLen) Type() *ast.Type {
return ast.NewFuncType(tokens.Token{}, n.Params(), n.Ret())
}
func (n builtInLen) String() string {
return n.Type().String()
}
func (n builtInLen) Params() []ast.Type {
// won't be arity or type checked
return []ast.Type{ast.TypeArray}
}
func (n builtInLen) Ret() *ast.Type {
return &ast.TypeNumber
}
func (n builtInLen) Call(interp *Interpreter, args []any, loc tokens.Location) (any, error) {
vals, ok := args[0].([]any)
if !ok {
// shouldn't happen
return nil, errors.NewError(errors.Unexpected, loc, "type mismatch in call to 'len'")
}
// return
panic(&PanicJump{typ: PanicJumpReturn, value: ast.Number(len(vals))})
}
type builtInPrintln struct{}
func (n builtInPrintln) Name() string {
return "'println'"
}
func (n builtInPrintln) Type() *ast.Type {
return ast.NewFuncType(tokens.Token{}, n.Params(), n.Ret())
}
func (n builtInPrintln) String() string {
return n.Type().String()
}
func (n builtInPrintln) Params() []ast.Type {
// won't be arity or type checked
return nil
}
func (n builtInPrintln) Ret() *ast.Type {
return &ast.TypeNumber
}
func (n builtInPrintln) Call(interp *Interpreter, args []any, loc tokens.Location) (any, error) {
var count int
for i := range args {
if args[i] == nil {
continue
}
written, err := fmt.Print(args[i])
if err != nil {
return nil, err
}
count += written
}
fmt.Println()
count++
// return
panic(&PanicJump{typ: PanicJumpReturn, value: ast.Number(count)})
}
type builtInPanic struct{}
func (n builtInPanic) Name() string {
return "'panic'"
}
func (n builtInPanic) Type() *ast.Type {
return ast.NewFuncType(tokens.Token{}, n.Params(), n.Ret())
}
func (n builtInPanic) String() string {
return n.Type().String()
}
func (n builtInPanic) Params() []ast.Type {
return []ast.Type{ast.TypeString}
}
func (n builtInPanic) Ret() *ast.Type {
// no return (returns none)
return nil
}
func (n builtInPanic) Call(interp *Interpreter, args []any, loc tokens.Location) (any, error) {
return nil, fmt.Errorf("[%s] panic: %s", loc, args[0])
}
type Function struct {
fun ast.Func
closure *Env
}
func (f Function) Name() string {
return f.fun.Name.String()
}
func (f Function) Type() *ast.Type {
return ast.NewFuncType(f.fun.Name, f.Params(), f.Ret())
}
func (f Function) String() string {
return f.Type().String()
}
func (f Function) Params() []ast.Type {
params := make([]ast.Type, 0, 1)
for _, p := range f.fun.Params {
params = append(params, p.Type)
}
return params
}
func (f Function) Ret() *ast.Type {
return f.fun.Ret
}
func (f Function) Call(interp *Interpreter, args []any, loc tokens.Location) (result any, err error) {
pEnv := interp.env
interp.env = NewEnv(f.closure)
defer func() {
interp.env = pEnv
}()
for n, v := range f.fun.Params {
interp.env = interp.env.Set(v.Name.Value, Var{Value: args[n], Loc: v.Name.Loc})
}
// tail call optimization
for {
// wrap the evaluation in a function
var tailCall *PanicJump
tailCall, result, err = func() (tailCall *PanicJump, result any, err error) {
// handle tail call
// will call this function again without setting up a new call frame
defer func() {
if r := recover(); r != nil {
if val, ok := r.(*PanicJump); ok && val.typ == PanicJumpTailCall {
tailCall = val
return
}
panic(r)
}
}()
result, err = interp.evaluate(f.fun.Body)
return nil, result, err
}()
if tailCall == nil {
break
}
// XXX: can we optimize this?
// if the callee can be a variable expression, we probably can't
call := tailCall.value.(ast.Call)
callee, err := interp.evaluate(call.Callee)
if err != nil {
return nil, err
}
if fun, ok := callee.(Callable); !ok || fun.Name() != f.Name() {
// can't be optimized
val, err := interp.evaluate(call)
if err != nil {
return nil, err
}
panic(&PanicJump{typ: PanicJumpReturn, value: val, loc: tailCall.loc})
}
args, err := interp.evalArgs(f.Name(), call.Loc, f.Params(), call.Args)
if err != nil {
return nil, err
}
for n, v := range f.fun.Params {
interp.env.Update(v.Name.Value, args[n])
}
}
return result, err
}
|
