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package env
import (
"errors"
//"fmt"
)
import (
. "types"
)
type Env struct {
data map[string]MalType
outer EnvType
}
func NewEnv(outer EnvType, binds_mt MalType, exprs_mt MalType) (EnvType, error) {
env := Env{map[string]MalType{}, outer}
if binds_mt != nil && exprs_mt != nil {
binds, e := GetSlice(binds_mt); if e != nil { return nil, e }
exprs, e := GetSlice(exprs_mt); if e != nil { return nil, e }
// Return a new Env with symbols in binds boudn to
// corresponding values in exprs
for i := 0; i < len(binds); i+=1 {
if (Symbol_Q(binds[i]) && binds[i].(Symbol).Val == "&") {
env.data[binds[i+1].(Symbol).Val] = List{exprs[i:],nil}
break
} else {
env.data[binds[i].(Symbol).Val] = exprs[i]
}
}
}
//return &et, nil
return env, nil
}
func (e Env) Find(key Symbol) EnvType {
if _, ok := e.data[key.Val]; ok {
return e
} else if (e.outer != nil) {
return e.outer.Find(key)
} else {
return nil
}
}
func (e Env) Set(key Symbol, value MalType) MalType {
e.data[key.Val] = value
return value
}
func (e Env) Get(key Symbol) (MalType, error) {
env := e.Find(key)
if env == nil {
return nil, errors.New("'" + key.Val + "' not found")
}
return env.(Env).data[key.Val], nil
}
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