115 lines
3.5 KiB
Go
115 lines
3.5 KiB
Go
package generate
|
|
|
|
import (
|
|
"fmt"
|
|
"go/types"
|
|
"regexp"
|
|
"strconv"
|
|
"strings"
|
|
)
|
|
|
|
func (g *generator) addImportFor(pkgPath string) (alias string) {
|
|
if alias, ok := g.imports[pkgPath]; ok {
|
|
return alias
|
|
}
|
|
|
|
pkgName := pkgPath[strings.LastIndex(pkgPath, "/")+1:]
|
|
alias = pkgName
|
|
suffix := 2
|
|
for g.usedAliases[alias] {
|
|
alias = pkgName + strconv.Itoa(suffix)
|
|
}
|
|
|
|
g.imports[pkgPath] = alias
|
|
g.usedAliases[alias] = true
|
|
return alias
|
|
}
|
|
|
|
// addRef adds any imports necessary to refer to the given name, and returns a
|
|
// reference alias.Name for it.
|
|
func (g *generator) addRef(fullyQualifiedName string) (qualifiedName string, err error) {
|
|
return g.getRef(fullyQualifiedName, true)
|
|
}
|
|
|
|
// ref returns a reference alias.Name for the given import, if its package was
|
|
// already added (e.g. via addRef), and an error if not.
|
|
func (g *generator) ref(fullyQualifiedName string) (qualifiedName string, err error) {
|
|
return g.getRef(fullyQualifiedName, false)
|
|
}
|
|
|
|
var _sliceOrMapPrefixRegexp = regexp.MustCompile(`^(\*|\[\d*\]|map\[string\])*`)
|
|
|
|
func (g *generator) getRef(fullyQualifiedName string, addImport bool) (qualifiedName string, err error) {
|
|
// Ideally, we want to allow a reference to basically an arbitrary symbol.
|
|
// But that's very hard, because it might be quite complicated, like
|
|
// struct{ F []map[mypkg.K]otherpkg.V }
|
|
// Now in practice, using an unnamed struct is not a great idea, but we do
|
|
// want to allow as much as we can that encoding/json knows how to work
|
|
// with, since you would reasonably expect us to accept, say,
|
|
// map[string][]interface{}. So we allow:
|
|
// - any named type (mypkg.T)
|
|
// - any predeclared basic type (string, int, etc.)
|
|
// - interface{}
|
|
// - for any allowed type T, *T, []T, [N]T, and map[string]T
|
|
// which effectively excludes:
|
|
// - unnamed struct types
|
|
// - map[K]V where K is a named type wrapping string
|
|
// - any nonstandard spelling of those (interface {/* hi */},
|
|
// map[ string ]T)
|
|
// TODO: document that somewhere visible
|
|
|
|
errorMsg := `invalid type-name "%v" (%v); expected a builtin, ` +
|
|
`path/to/package.Name, interface{}, or a slice, map, or pointer of those`
|
|
|
|
if strings.Contains(fullyQualifiedName, " ") {
|
|
// TODO: pass in pos here and below
|
|
return "", errorf(nil, errorMsg, fullyQualifiedName, "contains spaces")
|
|
}
|
|
|
|
prefix := _sliceOrMapPrefixRegexp.FindString(fullyQualifiedName)
|
|
nameToImport := fullyQualifiedName[len(prefix):]
|
|
|
|
i := strings.LastIndex(nameToImport, ".")
|
|
if i == -1 {
|
|
if nameToImport != "interface{}" && types.Universe.Lookup(nameToImport) == nil {
|
|
return "", errorf(nil, errorMsg, fullyQualifiedName,
|
|
fmt.Sprintf(`unknown type-name "%v"`, nameToImport))
|
|
}
|
|
return fullyQualifiedName, nil
|
|
}
|
|
|
|
pkgPath := nameToImport[:i]
|
|
localName := nameToImport[i+1:]
|
|
var alias string
|
|
if addImport {
|
|
alias = g.addImportFor(pkgPath)
|
|
} else {
|
|
var ok bool
|
|
alias, ok = g.imports[pkgPath]
|
|
if !ok {
|
|
// This is an internal error, not a user error.
|
|
return "", errorf(nil, `no alias defined for package "%v"`, pkgPath)
|
|
}
|
|
}
|
|
return prefix + alias + "." + localName, nil
|
|
}
|
|
|
|
// Returns the import-clause to use in the generated code.
|
|
func (g *generator) Imports() string {
|
|
if len(g.imports) == 0 {
|
|
return ""
|
|
}
|
|
|
|
var builder strings.Builder
|
|
builder.WriteString("import (\n")
|
|
for path, alias := range g.imports {
|
|
if path == alias || strings.HasSuffix(path, "/"+alias) {
|
|
builder.WriteString("\t" + strconv.Quote(path) + "\n")
|
|
} else {
|
|
builder.WriteString("\t" + alias + " " + strconv.Quote(path) + "\n")
|
|
}
|
|
}
|
|
builder.WriteString(")\n\n")
|
|
return builder.String()
|
|
}
|