func flow(root yaml.Node, env Environment, shouldOverride bool) yaml.Node {
if root == nil {
return root
}
replace := root.ReplaceFlag()
redirect := root.RedirectPath()
preferred := root.Preferred()
merged := root.Merged()
keyName := root.KeyName()
if redirect != nil {
env = env.RedirectOverwrite(redirect)
}
if !replace {
switch val := root.Value().(type) {
case map[string]yaml.Node:
return flowMap(root, env)
case []yaml.Node:
return flowList(root, env)
case dynaml.Expression:
debug.Debug("??? eval %+v\n", val)
result, info, ok := val.Evaluate(env)
if !ok {
root = yaml.IssueNode(root, info.Issue)
debug.Debug("??? failed ---> KEEP\n")
if !shouldOverride {
return root
}
replace = replace || info.Replace
} else {
_, ok = result.Value().(string)
if ok {
// map result to potential expression
result = flowString(result, env)
}
_, expr := result.Value().(dynaml.Expression)
// preserve accumulated node attributes
if preferred || info.Preferred {
debug.Debug(" PREFERRED")
result = yaml.PreferredNode(result)
}
if info.KeyName != "" {
keyName = info.KeyName
result = yaml.KeyNameNode(result, keyName)
}
if len(info.RedirectPath) > 0 {
redirect = info.RedirectPath
}
if len(redirect) > 0 {
debug.Debug(" REDIRECT -> %v\n", redirect)
result = yaml.RedirectNode(result.Value(), result, redirect)
}
if replace || info.Replace {
debug.Debug(" REPLACE\n")
result = yaml.ReplaceNode(result.Value(), result, redirect)
} else {
if merged || info.Merged {
debug.Debug(" MERGED\n")
result = yaml.MergedNode(result)
}
}
if expr || result.Merged() || !shouldOverride || result.Preferred() {
debug.Debug(" prefer expression over override")
debug.Debug("??? ---> %+v\n", result)
return result
}
debug.Debug("??? try override")
replace = result.ReplaceFlag()
root = result
}
case string:
result := flowString(root, env)
if result != nil {
_, ok := result.Value().(dynaml.Expression)
if ok {
// analyse expression before overriding
return result
}
}
}
}
if !merged && shouldOverride {
debug.Debug("/// lookup stub %v -> %v\n", env.Path, env.StubPath)
overridden, found := env.FindInStubs(env.StubPath)
if found {
root = overridden
if keyName != "" {
root = yaml.KeyNameNode(root, keyName)
}
if replace {
return yaml.ReplaceNode(root.Value(), root, redirect)
}
if redirect != nil {
return yaml.RedirectNode(root.Value(), root, redirect)
}
if merged {
return yaml.MergedNode(root)
}
}
}
return root
}