gcc/libgo/go/template/parse.go
Ian Lance Taylor 2fd401c8f1 libgo: Update to weekly.2011-11-02.
From-SVN: r181964
2011-12-03 02:17:34 +00:00

97 lines
2.7 KiB
Go

// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package template
import (
"reflect"
"template/parse"
)
// Template is the representation of a parsed template.
type Template struct {
name string
*parse.Tree
leftDelim string
rightDelim string
// We use two maps, one for parsing and one for execution.
// This separation makes the API cleaner since it doesn't
// expose reflection to the client.
parseFuncs FuncMap
execFuncs map[string]reflect.Value
set *Set // can be nil.
}
// Name returns the name of the template.
func (t *Template) Name() string {
return t.name
}
// Parsing.
// New allocates a new template with the given name.
func New(name string) *Template {
return &Template{
name: name,
parseFuncs: make(FuncMap),
execFuncs: make(map[string]reflect.Value),
}
}
// Delims sets the action delimiters, to be used in a subsequent
// parse, to the specified strings.
// An empty delimiter stands for the corresponding default: {{ or }}.
// The return value is the template, so calls can be chained.
func (t *Template) Delims(left, right string) *Template {
t.leftDelim = left
t.rightDelim = right
return t
}
// Funcs adds the elements of the argument map to the template's function
// map. It panics if a value in the map is not a function with appropriate
// return type.
// The return value is the template, so calls can be chained.
func (t *Template) Funcs(funcMap FuncMap) *Template {
addValueFuncs(t.execFuncs, funcMap)
addFuncs(t.parseFuncs, funcMap)
return t
}
// Parse parses the template definition string to construct an internal
// representation of the template for execution.
func (t *Template) Parse(s string) (tmpl *Template, err error) {
t.Tree, err = parse.New(t.name).Parse(s, t.leftDelim, t.rightDelim, t.parseFuncs, builtins)
if err != nil {
return nil, err
}
return t, nil
}
// ParseInSet parses the template definition string to construct an internal
// representation of the template for execution. It also adds the template
// to the set.
// Function bindings are checked against those in the set.
func (t *Template) ParseInSet(s string, set *Set) (tmpl *Template, err error) {
var setFuncs FuncMap
if set != nil {
setFuncs = set.parseFuncs
}
t.Tree, err = parse.New(t.name).Parse(s, t.leftDelim, t.rightDelim, t.parseFuncs, setFuncs, builtins)
if err != nil {
return nil, err
}
t.addToSet(set)
return t, nil
}
// addToSet adds the template to the set, verifying it's not being double-assigned.
func (t *Template) addToSet(set *Set) {
if set == nil || t.set == set {
return
}
// If double-assigned, Add will panic and we will turn that into an error.
set.Add(t)
}