import "go/parser"

Overview

Index

Examples

func ParseDir(fset *token.FileSet, path string, filter func(os.FileInfo) bool, mode Mode) (pkgs map[string]*ast.Package, first error)

func ParseExpr(x string) (ast.Expr, error)

func ParseFile(fset *token.FileSet, filename string, src interface{}, mode Mode) (*ast.File, error)

type Mode

Examples

ParseFile

Package files

interface.go parser.go

func ParseDir

func ParseDir(fset *token.FileSet, path string, filter func(os.FileInfo) bool, mode Mode) (pkgs map[string]*ast.Package, first error)

ParseDir calls ParseFile for the files in the directory specified by path and returns a map of package name -> package AST with all the packages found. If filter != nil, only the files with os.FileInfo entries passing through the filter are considered. The mode bits are passed to ParseFile unchanged. Position information is recorded in the file set fset.

If the directory couldn't be read, a nil map and the respective error are returned. If a parse error occurred, a non-nil but incomplete map and the first error encountered are returned.

func ParseExpr

func ParseExpr(x string) (ast.Expr, error)

ParseExpr is a convenience function for obtaining the AST of an expression x. The position information recorded in the AST is undefined.

func ParseFile

func ParseFile(fset *token.FileSet, filename string, src interface{}, mode Mode) (*ast.File, error)

ParseFile parses the source code of a single Go source file and returns the corresponding ast.File node. The source code may be provided via the filename of the source file, or via the src parameter.

If src != nil, ParseFile parses the source from src and the filename is only used when recording position information. The type of the argument for the src parameter must be string, []byte, or io.Reader. If src == nil, ParseFile parses the file specified by filename.

The mode parameter controls the amount of source text parsed and other optional parser functionality. Position information is recorded in the file set fset.

If the source couldn't be read, the returned AST is nil and the error indicates the specific failure. If the source was read but syntax errors were found, the result is a partial AST (with ast.Bad* nodes representing the fragments of erroneous source code). Multiple errors are returned via a scanner.ErrorList which is sorted by file position.

fset := token.NewFileSet() // positions are relative to fset

// Parse the file containing this very example
// but stop after processing the imports.
f, err := parser.ParseFile(fset, "example_test.go", nil, parser.ImportsOnly)
if err != nil {
    fmt.Println(err)
    return
}

// Print the imports from the file's AST.
for _, s := range f.Imports {
    fmt.Println(s.Path.Value)
}

"fmt"
"go/parser"
"go/token"

type Mode

type Mode uint

A Mode value is a set of flags (or 0). They control the amount of source code parsed and other optional parser functionality.

const (
    PackageClauseOnly Mode = 1 << iota // parsing stops after package clause
    ImportsOnly                        // parsing stops after import declarations
    ParseComments                      // parse comments and add them to AST
    Trace                              // print a trace of parsed productions
    DeclarationErrors                  // report declaration errors
    SpuriousErrors                     // report all (not just the first) errors per line
)