/
restorer.go
168 lines (159 loc) · 6.54 KB
/
restorer.go
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package main
import (
"fmt"
"github.com/dave/dst/gendst/data"
. "github.com/dave/jennifer/jen"
)
func generateRestorer(names []string) error {
f := NewFile("decorator")
f.ImportName(DSTPATH, "dst")
// func (r *restorer) restoreNode(n dst.Node, allowDuplicate bool) ast.Node {
// switch n := n.(type) {
// case <type>:
// ...
// default:
// panic(...)
// }
// }
f.Func().Params(Id("r").Op("*").Id("FileRestorer")).Id("restoreNode").Params(
Id("n").Qual(DSTPATH, "Node"),
Id("parentName"),
Id("parentField"),
Id("parentFieldType").String(),
Id("allowDuplicate").Bool(),
).Qual("go/ast", "Node").BlockFunc(func(g *Group) {
g.If(List(Id("an"), Id("ok")).Op(":=").Id("r").Dot("Ast").Dot("Nodes").Index(Id("n")), Id("ok")).Block(
If(Id("allowDuplicate")).Block(
Return(Id("an")),
).Else().Block(
Panic(Qual("fmt", "Sprintf").Call(Lit("duplicate node: %#v"), Id("n"))),
),
)
g.Switch(Id("n").Op(":=").Id("n").Assert(Id("type"))).BlockFunc(func(g *Group) {
for _, nodeName := range names {
g.Case(Op("*").Qual(DSTPATH, nodeName)).BlockFunc(func(g *Group) {
if nodeName == "Ident" {
g.Line()
g.Comment("Special case for *dst.Ident - replace with SelectorExpr if needed")
g.Id("sel").Op(":=").Id("r").Dot("restoreIdent").Call(Id("n"), Id("parentName"), Id("parentField"), Id("parentFieldType"), Id("allowDuplicate"))
g.If(Id("sel").Op("!=").Nil()).Block(
Return(Id("sel")),
)
g.Line()
}
g.Id("out").Op(":=").Op("&").Qual("go/ast", nodeName).Values()
g.Id("r").Dot("Ast").Dot("Nodes").Index(Id("n")).Op("=").Id("out")
g.Id("r").Dot("Dst").Dot("Nodes").Index(Id("out")).Op("=").Id("n")
if nodeName != "Package" {
g.Id("r").Dot("applySpace").Call(Id("n").Dot("Decs").Dot("Before"))
}
for _, frag := range data.Info[nodeName] {
switch frag := frag.(type) {
case data.Init:
g.Line().Commentf("Init: %s", frag.Name)
g.Add(frag.Field.Get("out")).Op("=").Op("&").Qual("go/ast", frag.Type.TypeName()).Values()
case data.Decoration:
g.Line().Commentf("Decoration: %s", frag.Name)
g.Id("r").Dot("applyDecorations").Call(Id("out"), Id("n").Dot("Decs").Dot(frag.Name), Do(func(s *Statement) { s.Lit(frag.Name == "End") }))
case data.SpecialDecoration:
g.Line().Commentf("Special decoration: %s", frag.Name)
g.Id("r").Dot("applyDecorations").Call(Id("out"), frag.Decs.Get("n").Dot(frag.Name), Lit(frag.End))
case data.Token:
g.Line().Commentf("Token: %s", frag.Name)
position := Null()
value := Null()
if frag.PositionField != nil {
position = frag.PositionField.Get("out").Op("=").Id("r").Dot("cursor")
}
if frag.TokenField != nil {
value = frag.TokenField.Get("out").Op("=").Add(frag.Token.Get("n", false))
}
action := Id("r").Dot("cursor").Op("+=").Qual("go/token", "Pos").Parens(
Len(frag.Token.Get("n", false).Dot("String").Call()),
)
if frag.Exists != nil {
g.If(frag.Exists.Get("n", false)).Block(value, position, action)
} else {
g.Add(value)
g.Add(position)
g.Add(action)
}
case data.String:
g.Line().Commentf("String: %s", frag.Name)
if frag.Literal {
g.Id("r").Dot("applyLiteral").Call(frag.ValueField.Get("n"))
}
if frag.PositionField != nil {
g.Add(frag.PositionField.Get("out")).Op("=").Id("r").Dot("cursor")
}
g.Add(frag.ValueField.Get("out")).Op("=").Add(frag.ValueField.Get("n"))
g.Id("r").Dot("cursor").Op("+=").Qual("go/token", "Pos").Parens(
Len(frag.ValueField.Get("n")),
)
case data.Node:
g.Line().Commentf("Node: %s", frag.Name)
/*
if n.Elt != nil {
out.Elt = r.restoreNode(n.Elt).(ast.Expr)
}
*/
g.If(frag.Field.Get("n").Op("!=").Nil()).Block(
frag.Field.Get("out").Op("=").Id("r").Dot("restoreNode").Call(frag.Field.Get("n"), Lit(nodeName), Lit(frag.Field.FieldName()), Lit(frag.Type.TypeName()), Id("allowDuplicate")).Assert(frag.Type.Literal("go/ast")),
)
case data.List:
g.Line().Commentf("List: %s", frag.Name)
g.For(List(Id("_"), Id("v")).Op(":=").Range().Add(frag.Field.Get("n"))).Block(
frag.Field.Get("out").Op("=").Append(
frag.Field.Get("out"),
Id("r").Dot("restoreNode").Call(Id("v"), Lit(nodeName), Lit(frag.Field.FieldName()), Lit(frag.Elem.TypeName()), Id("allowDuplicate")).Assert(frag.Elem.Literal("go/ast")),
),
)
case data.Map:
g.Line().Commentf("Map: %s", frag.Name)
g.Add(frag.Field.Get("out")).Op("=").Map(String()).Add(frag.Elem.Literal("go/ast")).Values()
g.For(List(Id("k"), Id("v")).Op(":=").Range().Add(frag.Field.Get("n"))).BlockFunc(func(g *Group) {
if frag.Elem.TypeName() == "Object" {
g.Add(frag.Field.Get("out")).Index(Id("k")).Op("=").Id("r").Dot("restoreObject").Call(Id("v"))
} else {
g.Add(frag.Field.Get("out")).Index(Id("k")).Op("=").Id("r").Dot("restoreNode").Call(Id("v"), Lit(nodeName), Lit(frag.Field.FieldName()), Lit(frag.Elem.TypeName()), Id("allowDuplicate")).Assert(frag.Elem.Literal("go/ast"))
}
})
case data.Bad:
g.Line().Comment("Bad")
g.Add(frag.FromField.Get("out")).Op("=").Id("r").Dot("cursor")
g.Id("r").Dot("cursor").Op("+=").Qual("go/token", "Pos").Parens(frag.Length.Get("n", false))
g.Add(frag.ToField.Get("out")).Op("=").Id("r").Dot("cursor")
case data.Value:
g.Line().Commentf("Value: %s", frag.Name)
if frag.Value != nil {
g.Add(frag.Field.Get("out")).Op("=").Add(frag.Value.Get("n", false))
} else {
g.Add(frag.Field.Get("out")).Op("=").Add(frag.Field.Get("n"))
}
case data.Scope:
g.Line().Commentf("Scope: %s", frag.Name)
g.Add(frag.Field.Get("out")).Op("=").Id("r").Dot("restoreScope").Call(frag.Field.Get("n"))
case data.Object:
g.Line().Commentf("Object: %s", frag.Name)
g.Add(frag.Field.Get("out")).Op("=").Id("r").Dot("restoreObject").Call(frag.Field.Get("n"))
case data.PathDecoration:
// nothing
default:
panic(fmt.Sprintf("unknown fragment type %T", frag))
}
}
if nodeName != "Package" {
g.Id("r").Dot("applySpace").Call(Id("n").Dot("Decs").Dot("After"))
}
g.Line()
g.Return(Id("out"))
})
}
g.Default().Block(
Panic(Qual("fmt", "Sprintf").Call(Lit("%T"), Id("n"))),
)
})
g.Return(Nil())
})
return f.Save("./decorator/restorer-generated.go")
}