Method handleKeyValueExpression

unmarshaler.go:1341–1379

handleKeyValueExpression stores the value of a top-level key-value expression, relative to the current table.

(expr *unstable.Node, root reflect.Value)

// handleKeyValueExpression stores the value of a top-level key-value
// expression, relative to the current table.
func (d *decoder) handleKeyValueExpression(expr *unstable.Node, root reflect.Value) error {
	d.path = d.path[:0]

	target := root
	useCache := d.tableTargetValid && len(d.tableKey) > 0
	if useCache {
		target = d.tableTarget
	} else {
		for _, name := range d.tableKey {
			d.path = append(d.path, pathPart{name: name})
		}
	}

	it := expr.Key()
	for it.Next() {
		d.path = append(d.path, pathPart{node: it.Node()})
	}

	nv, err := d.descend(target, d.path, 0, expr, expr.Value())
	if err != nil {
		return d.contextualizeError(err, useCache)
	}
	if !nv.IsValid() {
		return nil
	}
	if useCache {
		// The target may have been replaced (e.g. a nil map allocated):
		// re-link it into its parent.
		if nv.Kind() == reflect.Map && nv.Pointer() != d.tableTarget.Pointer() {
			d.storeSlot(&d.tableParentSlot, nv)
			d.tableTarget = nv
		}
	} else {
		if root.CanSet() {
			root.Set(nv)
		}
	}
	return nil
}

// descend walks the given key path into v, and assigns the value at the
// end. It returns the value to store back at this level. An invalid value