func (d *desc) Visit(node ast.Node) ast.Visitor {
switch v := node.(type) {
case *ast.RuleSpec:
for i := range v.Values {
ast.Walk(d, v.Values[i])
}
case *ast.GenDecl:
for _, spec := range v.Specs {
ast.Walk(d, spec)
}
return nil
case *ast.CallExpr:
d.c.name = v.Fun.(*ast.Ident).Name
for _, arg := range v.Args {
switch v := arg.(type) {
case *ast.KeyValueExpr:
d.c.params = append(d.c.params, v)
case *ast.Ident:
d.c.params = append(d.c.params, &ast.KeyValueExpr{
Key: v,
})
default:
panic(fmt.Errorf("%s failed to parse arg % #v\n",
d.c.name, v))
}
}
return nil
case nil:
return nil
default:
panic(fmt.Errorf("illegal walk % #v\n", v))
}
return d
}
func (ctx *Context) run(path string, src interface{}) ([]byte, error) {
ctx.fset = token.NewFileSet()
// ctx.mode = parser.Trace
pf, err := parser.ParseFile(ctx.fset, path, src, ctx.mode)
if err != nil {
return nil, err
}
ast.Walk(ctx, pf)
lr, _ := utf8.DecodeLastRune(ctx.buf.Bytes())
_ = lr
if ctx.buf.Len() > 0 && lr != '\n' {
ctx.out("\n")
}
// ctx.printSels(pf.Decls)
return ctx.buf.Bytes(), nil
}
func register(s string, ch builtin.CallFunc, h builtin.CallHandle) {
fset := token.NewFileSet()
pf, err := ParseFile(fset, "", s, FuncOnly)
if err != nil {
if !strings.HasSuffix(err.Error(), "expected ';', found 'EOF'") {
log.Fatal(err)
}
}
d := &desc{c: call{
ch: ch,
handle: h,
}}
ast.Walk(d, pf.Decls[0])
if d.err != nil {
log.Fatal("failed to parse func description", d.err)
}
if _, ok := builtins[d.c.name]; ok {
log.Println("already registered", d.c.name)
}
builtins[d.c.name] = d.c
}
// Visit is an internal compiler method. It is exported to allow ast.Walk
// to walk through the parser AST tree.
func (ctx *Context) Visit(node ast.Node) ast.Visitor {
if ctx.err != nil {
fmt.Println(ctx.err)
return nil
}
var key ast.Node
switch v := node.(type) {
case *ast.BlockStmt:
if (ctx.scope.RuleLen() > 0 || ctx.activeMedia != nil) &&
!ctx.hiddenBlock {
ctx.level = ctx.level + 1
if !ctx.firstRule {
fmt.Fprintf(ctx.buf, " }\n")
}
}
ctx.scope = NewScope(ctx.scope)
if !ctx.hiddenBlock {
ctx.firstRule = true
}
for _, node := range v.List {
ast.Walk(ctx, node)
}
if ctx.level > 0 {
ctx.level = ctx.level - 1
}
ctx.scope = CloseScope(ctx.scope)
if !ctx.hiddenBlock {
ctx.blockOutro()
ctx.firstRule = true
}
ctx.hiddenBlock = false
// ast.Walk(ctx, v.List)
// fmt.Fprintf(ctx.buf, "}")
return nil
case *ast.SelDecl:
case *ast.File, *ast.GenDecl, *ast.Value:
// Nothing to print for these
case *ast.Ident:
// The first IDENT is always the filename, just preserve
// it somewhere
key = ident
case *ast.PropValueSpec:
key = propSpec
case *ast.DeclStmt:
key = declStmt
case *ast.IncludeSpec:
// panic("not supported")
case *ast.ValueSpec:
key = valueSpec
case *ast.RuleSpec:
key = ruleSpec
case *ast.SelStmt:
// We will need to combine parent selectors
// while printing these
key = selStmt
// Nothing to do
case *ast.CommStmt:
case *ast.CommentGroup:
case *ast.Comment:
key = comment
case *ast.FuncDecl:
ctx.printers[funcDecl](ctx, node)
// Do not traverse mixins in the regular context
return nil
case *ast.BasicLit:
return ctx
case *ast.CallExpr:
case nil:
return ctx
case *ast.MediaStmt:
fmt.Println("mediastmt")
key = mediaStmt
case *ast.EmptyStmt:
case *ast.AssignStmt:
key = assignStmt
case *ast.EachStmt:
key = eachStmt
case *ast.ListLit:
case *ast.ImportSpec:
case *ast.IfDecl:
case *ast.IfStmt:
key = ifStmt
default:
fmt.Printf("add printer for: %T\n", v)
fmt.Printf("% #v\n", v)
}
ctx.printers[key](ctx, node)
return ctx
}
func printInclude(ctx *Context, n ast.Node) {
panic("dont call this")
spec := n.(*ast.IncludeSpec)
name := spec.Name.String()
var params []*ast.Field
if spec.Params != nil {
params = spec.Params.List
}
numargs := spec.Params.NumFields()
mix, err := ctx.scope.Mixin(name, numargs)
if err != nil {
log.Fatal(err)
}
// Add new scope, register args
ctx.scope = NewScope(ctx.scope)
mixargs := mix.fn.Type.Params.List
for i := range mixargs {
// Param passed by include
var param *ast.Field
if len(params) > i {
param = params[i]
}
var (
key *ast.BasicLit
val *ast.Ident
)
_, _ = key, val
switch v := mixargs[i].Type.(type) {
case *ast.BasicLit:
key = v
case *ast.KeyValueExpr:
key = v.Key.(*ast.BasicLit)
val = ast.ToIdent(v.Value)
}
if param != nil {
switch v := param.Type.(type) {
case *ast.KeyValueExpr:
// Key args specify their argument, so use their key
// instead of the mixins argument for this position
// Params with defaults
key = v.Key.(*ast.BasicLit)
val = ast.ToIdent(v.Value)
case *ast.Ident:
val = v
case *ast.BasicLit:
val = ast.ToIdent(v)
default:
fmt.Printf("dropped param: % #v\n", v)
}
}
// if key != nil && val != nil {
// ctx.scope.Insert(key.Value, val.Name)
// }
}
if len(params) > len(mixargs) {
fmt.Printf("dropped extra params: % #v\n", params[len(mixargs):])
}
for _, stmt := range mix.fn.Body.List {
ast.Walk(ctx, stmt)
}
// Exit new scope, removing args
ctx.scope = CloseScope(ctx.scope)
}