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- package vals
- import (
- "fmt"
- "math"
- "math/big"
- "reflect"
- "strconv"
- "src.elv.sh/pkg/parse"
- )
- // 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
- }
- // ReprPlain is like Repr, but without pretty-printing.
- func ReprPlain(v interface{}) string {
- return Repr(v, math.MinInt)
- }
- // Repr returns the representation for a value, a string that is preferably
- // (but not necessarily) an Elvish expression that evaluates to the argument.
- // The representation is pretty-printed, using indent as the initial level of
- // indentation. 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 int:
- return "(num " + strconv.Itoa(v) + ")"
- case *big.Int:
- return "(num " + v.String() + ")"
- case *big.Rat:
- return "(num " + v.String() + ")"
- case float64:
- return "(num " + formatFloat64(v) + ")"
- case Reprer:
- return v.Repr(indent)
- 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:
- return reprStructMap(v, indent)
- case PseudoStructMap:
- return reprStructMap(v.Fields(), indent)
- default:
- return fmt.Sprintf("<unknown %v>", v)
- }
- }
- func reprStructMap(v StructMap, indent int) string {
- vValue := reflect.ValueOf(v)
- vType := vValue.Type()
- builder := NewMapReprBuilder(indent)
- it := iterateStructMap(vType)
- for it.Next() {
- k, v := it.Get(vValue)
- builder.WritePair(Repr(k, indent+1), indent+2, Repr(v, indent+2))
- }
- return builder.String()
- }
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