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
|
package script
import (
"context"
"fmt"
"github.com/d5/tengo/compiler"
"github.com/d5/tengo/compiler/parser"
"github.com/d5/tengo/compiler/source"
"github.com/d5/tengo/objects"
"github.com/d5/tengo/runtime"
)
// Script can simplify compilation and execution of embedded scripts.
type Script struct {
variables map[string]*Variable
builtinFuncs []objects.Object
builtinModules map[string]*objects.Object
userModuleLoader compiler.ModuleLoader
input []byte
}
// New creates a Script instance with an input script.
func New(input []byte) *Script {
return &Script{
variables: make(map[string]*Variable),
input: input,
}
}
// Add adds a new variable or updates an existing variable to the script.
func (s *Script) Add(name string, value interface{}) error {
obj, err := objects.FromInterface(value)
if err != nil {
return err
}
s.variables[name] = &Variable{
name: name,
value: &obj,
}
return nil
}
// Remove removes (undefines) an existing variable for the script.
// It returns false if the variable name is not defined.
func (s *Script) Remove(name string) bool {
if _, ok := s.variables[name]; !ok {
return false
}
delete(s.variables, name)
return true
}
// SetBuiltinFunctions allows to define builtin functions.
func (s *Script) SetBuiltinFunctions(funcs []*objects.BuiltinFunction) {
if funcs != nil {
s.builtinFuncs = make([]objects.Object, len(funcs))
for idx, fn := range funcs {
s.builtinFuncs[idx] = fn
}
} else {
s.builtinFuncs = []objects.Object{}
}
}
// SetBuiltinModules allows to define builtin modules.
func (s *Script) SetBuiltinModules(modules map[string]*objects.ImmutableMap) {
if modules != nil {
s.builtinModules = make(map[string]*objects.Object, len(modules))
for k, mod := range modules {
s.builtinModules[k] = objectPtr(mod)
}
} else {
s.builtinModules = map[string]*objects.Object{}
}
}
// SetUserModuleLoader sets the user module loader for the compiler.
func (s *Script) SetUserModuleLoader(loader compiler.ModuleLoader) {
s.userModuleLoader = loader
}
// Compile compiles the script with all the defined variables, and, returns Compiled object.
func (s *Script) Compile() (*Compiled, error) {
symbolTable, builtinModules, globals, err := s.prepCompile()
if err != nil {
return nil, err
}
fileSet := source.NewFileSet()
srcFile := fileSet.AddFile("(main)", -1, len(s.input))
p := parser.NewParser(srcFile, s.input, nil)
file, err := p.ParseFile()
if err != nil {
return nil, err
}
c := compiler.NewCompiler(srcFile, symbolTable, nil, builtinModules, nil)
if s.userModuleLoader != nil {
c.SetModuleLoader(s.userModuleLoader)
}
if err := c.Compile(file); err != nil {
return nil, err
}
return &Compiled{
symbolTable: symbolTable,
machine: runtime.NewVM(c.Bytecode(), globals, s.builtinFuncs, s.builtinModules),
}, nil
}
// Run compiles and runs the scripts.
// Use returned compiled object to access global variables.
func (s *Script) Run() (compiled *Compiled, err error) {
compiled, err = s.Compile()
if err != nil {
return
}
err = compiled.Run()
return
}
// RunContext is like Run but includes a context.
func (s *Script) RunContext(ctx context.Context) (compiled *Compiled, err error) {
compiled, err = s.Compile()
if err != nil {
return
}
err = compiled.RunContext(ctx)
return
}
func (s *Script) prepCompile() (symbolTable *compiler.SymbolTable, builtinModules map[string]bool, globals []*objects.Object, err error) {
var names []string
for name := range s.variables {
names = append(names, name)
}
symbolTable = compiler.NewSymbolTable()
if s.builtinFuncs == nil {
s.builtinFuncs = make([]objects.Object, len(objects.Builtins))
for idx, fn := range objects.Builtins {
s.builtinFuncs[idx] = &objects.BuiltinFunction{
Name: fn.Name,
Value: fn.Value,
}
}
}
if s.builtinModules == nil {
s.builtinModules = make(map[string]*objects.Object)
}
for idx, fn := range s.builtinFuncs {
f := fn.(*objects.BuiltinFunction)
symbolTable.DefineBuiltin(idx, f.Name)
}
builtinModules = make(map[string]bool)
for name := range s.builtinModules {
builtinModules[name] = true
}
globals = make([]*objects.Object, runtime.GlobalsSize, runtime.GlobalsSize)
for idx, name := range names {
symbol := symbolTable.Define(name)
if symbol.Index != idx {
panic(fmt.Errorf("wrong symbol index: %d != %d", idx, symbol.Index))
}
globals[symbol.Index] = s.variables[name].value
}
return
}
func (s *Script) copyVariables() map[string]*Variable {
vars := make(map[string]*Variable)
for n, v := range s.variables {
vars[n] = v
}
return vars
}
func objectPtr(o objects.Object) *objects.Object {
return &o
}
|
