mirror of
https://github.com/go-sylixos/elvish.git
synced 2024-12-05 03:17:50 +08:00
78 lines
2.4 KiB
Go
78 lines
2.4 KiB
Go
package vals
|
|
|
|
import (
|
|
"fmt"
|
|
"reflect"
|
|
|
|
"github.com/elves/elvish/pkg/parse"
|
|
"github.com/elves/elvish/pkg/util"
|
|
)
|
|
|
|
// NoPretty can be passed to Repr to suppress pretty-printing.
|
|
const NoPretty = util.MinInt
|
|
|
|
// Reprer wraps the Repr method.
|
|
type Reprer interface {
|
|
// Repr returns a string that represents a Value. The string either be a
|
|
// literal of that Value that is preferably deep-equal to it (like `[a b c]`
|
|
// for a list), or a string enclosed in "<>" containing the kind and
|
|
// identity of the Value(like `<fn 0xdeadcafe>`).
|
|
//
|
|
// If indent is at least 0, it should be pretty-printed with the current
|
|
// indentation level of indent; the indent of the first line has already
|
|
// been written and shall not be written in Repr. The returned string
|
|
// should never contain a trailing newline.
|
|
Repr(indent int) string
|
|
}
|
|
|
|
// Repr returns the representation for a value, a string that is preferably (but
|
|
// not necessarily) an Elvish expression that evaluates to the argument. If
|
|
// indent >= 0, the representation is pretty-printed. It is implemented for the
|
|
// builtin types nil, bool and string, the File, List and Map types, StructMap
|
|
// types, and types satisfying the Reprer interface. For other types, it uses
|
|
// fmt.Sprint with the format "<unknown %v>".
|
|
func Repr(v interface{}, indent int) string {
|
|
switch v := v.(type) {
|
|
case nil:
|
|
return "$nil"
|
|
case bool:
|
|
if v {
|
|
return "$true"
|
|
}
|
|
return "$false"
|
|
case string:
|
|
return parse.Quote(v)
|
|
case float64:
|
|
return fmt.Sprintf("(float64 %g)", v)
|
|
case File:
|
|
return fmt.Sprintf("<file{%s %d}>", parse.Quote(v.Name()), v.Fd())
|
|
case List:
|
|
b := NewListReprBuilder(indent)
|
|
for it := v.Iterator(); it.HasElem(); it.Next() {
|
|
b.WriteElem(Repr(it.Elem(), indent+1))
|
|
}
|
|
return b.String()
|
|
case Map:
|
|
builder := NewMapReprBuilder(indent)
|
|
for it := v.Iterator(); it.HasElem(); it.Next() {
|
|
k, v := it.Elem()
|
|
builder.WritePair(Repr(k, indent+1), indent+2, Repr(v, indent+2))
|
|
}
|
|
return builder.String()
|
|
case StructMap:
|
|
info := getStructMapInfo(reflect.TypeOf(v))
|
|
vv := reflect.ValueOf(v)
|
|
n := vv.NumField()
|
|
builder := NewMapReprBuilder(indent)
|
|
for i := 0; i < n; i++ {
|
|
builder.WritePair(Repr(info.fieldNames[i], indent+1),
|
|
indent+2, Repr(vv.Field(i).Interface(), indent+2))
|
|
}
|
|
return builder.String()
|
|
case Reprer:
|
|
return v.Repr(indent)
|
|
default:
|
|
return fmt.Sprintf("<unknown %v>", v)
|
|
}
|
|
}
|