vendor.github.com.mmcloughlin.avo.printer.printer.go Maven / Gradle / Ivy
// Package printer implements printing of avo files in various formats.
package printer
import (
"fmt"
"os"
"path/filepath"
"strings"
"github.com/mmcloughlin/avo/internal/stack"
"github.com/mmcloughlin/avo/ir"
)
// Printer can produce output for an avo File.
type Printer interface {
Print(*ir.File) ([]byte, error)
}
// Builder can construct a printer.
type Builder func(Config) Printer
// Config represents general printing configuration.
type Config struct {
// Command-line arguments passed to the generator. If provided, this will be
// included in a code generation warning.
Argv []string
// Name of the code generator.
Name string
// Name of Go package the generated code will belong to.
Pkg string
}
// NewDefaultConfig produces a config with Name "avo".
// The package name is guessed from the current directory.
func NewDefaultConfig() Config {
return Config{
Name: "avo",
Pkg: pkg(),
}
}
// NewArgvConfig constructs a Config from os.Args.
// The package name is guessed from the current directory.
func NewArgvConfig() Config {
return Config{
Argv: os.Args,
Pkg: pkg(),
}
}
// NewGoRunConfig produces a Config for a generator that's expected to be
// executed via "go run ...".
func NewGoRunConfig() Config {
path := mainfile()
if path == "" {
return NewDefaultConfig()
}
argv := []string{"go", "run", filepath.Base(path)}
if len(os.Args) > 1 {
argv = append(argv, os.Args[1:]...)
}
return Config{
Argv: argv,
Pkg: pkg(),
}
}
// GeneratedBy returns a description of the code generator.
func (c Config) GeneratedBy() string {
if c.Argv == nil {
return c.Name
}
return fmt.Sprintf("command: %s", strings.Join(c.Argv, " "))
}
// GeneratedWarning returns text for a code generation warning. Conforms to https://golang.org/s/generatedcode.
func (c Config) GeneratedWarning() string {
return fmt.Sprintf("Code generated by %s. DO NOT EDIT.", c.GeneratedBy())
}
// mainfile attempts to determine the file path of the main function by
// inspecting the stack. Returns empty string on failure.
func mainfile() string {
if m := stack.Main(); m != nil {
return m.File
}
return ""
}
// pkg guesses the name of the package from the working directory.
func pkg() string {
if cwd, err := os.Getwd(); err == nil {
return filepath.Base(cwd)
}
return ""
}