github.com/jmigpin/editor@v1.6.0/util/astut/util.go (about)

     1  package astut
     2  
     3  import (
     4  	"bytes"
     5  	"fmt"
     6  	"go/ast"
     7  	"go/printer"
     8  	"go/token"
     9  )
    10  
    11  func NodeFilename(fset *token.FileSet, node ast.Node) (string, error) {
    12  	f := fset.File(node.Pos())
    13  	if f == nil {
    14  		return "", fmt.Errorf("not found")
    15  	}
    16  	return f.Name(), nil
    17  }
    18  
    19  //----------
    20  
    21  // print ast notes
    22  // TODO: without tabwidth set, it won't output the source correctly
    23  // Fail: has struct fields without spaces "field int"->"fieldint"
    24  //cfg := &printer.Config{Mode: printer.SourcePos | printer.TabIndent}
    25  // Fail: has stmts split with comments in the middle
    26  //cfg := &printer.Config{Mode: printer.SourcePos | printer.TabIndent | printer.UseSpaces}
    27  // debug
    28  //cfg := &printer.Config{Tabwidth: 4}
    29  //cfg := &printer.Config{Mode: printer.SourcePos, Tabwidth: 4}
    30  
    31  func PrintNode(fset *token.FileSet, n ast.Node) {
    32  	fmt.Println(SprintNode(fset, n))
    33  }
    34  func SprintNode(fset *token.FileSet, n ast.Node) string {
    35  	s, err := SprintNode2(fset, n)
    36  	if err != nil {
    37  		return fmt.Sprintf("<sprintnodeerr:%v>", err)
    38  	}
    39  	return s
    40  }
    41  func SprintNode2(fset *token.FileSet, n ast.Node) (string, error) {
    42  	buf := &bytes.Buffer{}
    43  	cfg := &printer.Config{Mode: printer.RawFormat}
    44  	if err := cfg.Fprint(buf, fset, n); err != nil {
    45  		return "", err
    46  	}
    47  	return string(buf.Bytes()), nil
    48  }