1 files changed, 108 insertions, 0 deletions
diff --git a/src/pkg/template/set.go b/src/pkg/template/set.go
new file mode 100644
index 000000000..f778fd169
--- /dev/null
+++ b/src/pkg/template/set.go
@@ -0,0 +1,108 @@
+// 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 (
+	"fmt"
+	"io"
+	"os"
+	"reflect"
+	"template/parse"
+)
+
+// Set holds a set of related templates that can refer to one another by name.
+// The zero value represents an empty set.
+// A template may be a member of multiple sets.
+type Set struct {
+	tmpl       map[string]*Template
+	parseFuncs FuncMap
+	execFuncs  map[string]reflect.Value
+}
+
+func (s *Set) init() {
+	if s.tmpl == nil {
+		s.tmpl = make(map[string]*Template)
+		s.parseFuncs = make(FuncMap)
+		s.execFuncs = make(map[string]reflect.Value)
+	}
+}
+
+// Funcs adds the elements of the argument map to the set's function map.  It
+// panics if a value in the map is not a function with appropriate return
+// type.
+// The return value is the set, so calls can be chained.
+func (s *Set) Funcs(funcMap FuncMap) *Set {
+	s.init()
+	addValueFuncs(s.execFuncs, funcMap)
+	addFuncs(s.parseFuncs, funcMap)
+	return s
+}
+
+// Add adds the argument templates to the set. It panics if two templates
+// with the same name are added or if a template is already a member of
+// a set.
+// The return value is the set, so calls can be chained.
+func (s *Set) Add(templates ...*Template) *Set {
+	for _, t := range templates {
+		if err := s.add(t); err != nil {
+			panic(err)
+		}
+	}
+	return s
+}
+
+// add adds the argument template to the set.
+func (s *Set) add(t *Template) os.Error {
+	s.init()
+	if t.set != nil {
+		return fmt.Errorf("template: %q already in a set", t.name)
+	}
+	if _, ok := s.tmpl[t.name]; ok {
+		return fmt.Errorf("template: %q already defined in set", t.name)
+	}
+	s.tmpl[t.name] = t
+	t.set = s
+	return nil
+}
+
+// Template returns the template with the given name in the set,
+// or nil if there is no such template.
+func (s *Set) Template(name string) *Template {
+	return s.tmpl[name]
+}
+
+// FuncMap returns the set's function map.
+func (s *Set) FuncMap() FuncMap {
+	return s.parseFuncs
+}
+
+// Execute applies the named template to the specified data object, writing
+// the output to wr.
+func (s *Set) Execute(wr io.Writer, name string, data interface{}) os.Error {
+	tmpl := s.tmpl[name]
+	if tmpl == nil {
+		return fmt.Errorf("template: no template %q in set", name)
+	}
+	return tmpl.Execute(wr, data)
+}
+
+// Parse parses a string into a set of named templates.  Parse may be called
+// multiple times for a given set, adding the templates defined in the string
+// to the set.  If a template is redefined, the element in the set is
+// overwritten with the new definition.
+func (s *Set) Parse(text string) (*Set, os.Error) {
+	trees, err := parse.Set(text, s.parseFuncs, builtins)
+	if err != nil {
+		return nil, err
+	}
+	s.init()
+	for name, tree := range trees {
+		tmpl := New(name)
+		tmpl.Tree = tree
+		tmpl.addToSet(s)
+		s.tmpl[name] = tmpl
+	}
+	return s, nil
+}