From c507e2717df7dd4b870478033bc5ece0b039a8c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Erik=20Pedersen?=
 <bjorn.erik.pedersen@gmail.com>
Date: Fri, 17 Feb 2017 13:30:50 +0100
Subject: [PATCH] tpl: Refactor package

Now:

* The template API lives in /tpl
* The rest lives in /tpl/tplimpl

This is bound te be more improved in the future.

Updates #2701
---
 deps/deps.go                                  |   8 +-
 hugolib/embedded_shortcodes_test.go           |   6 +-
 hugolib/hugo_sites.go                         |  12 +-
 hugolib/shortcode.go                          |   4 +-
 hugolib/shortcode_test.go                     |  38 +-
 hugolib/site.go                               |  10 +-
 hugolib/sitemap_test.go                       |   4 +-
 hugolib/testhelpers_test.go                   |   6 +-
 tpl/template.go                               | 586 +-----------------
 tpl/{ => tplimpl}/amber_compiler.go           |   2 +-
 tpl/{ => tplimpl}/reflect_helpers.go          |   4 +-
 tpl/tplimpl/template.go                       | 575 +++++++++++++++++
 .../template_ast_transformers.go              |   2 +-
 .../template_ast_transformers_test.go         |   2 +-
 tpl/{ => tplimpl}/template_embedded.go        |   2 +-
 tpl/{ => tplimpl}/template_func_truncate.go   |   2 +-
 .../template_func_truncate_test.go            |   2 +-
 tpl/{ => tplimpl}/template_funcs.go           |   2 +-
 tpl/{ => tplimpl}/template_funcs_test.go      |  14 +-
 tpl/{ => tplimpl}/template_resources.go       |   2 +-
 tpl/{ => tplimpl}/template_resources_test.go  |   2 +-
 tpl/{ => tplimpl}/template_test.go            |  10 +-
 tplapi/template.go                            |  28 -
 23 files changed, 661 insertions(+), 662 deletions(-)
 rename tpl/{ => tplimpl}/amber_compiler.go (98%)
 rename tpl/{ => tplimpl}/reflect_helpers.go (96%)
 create mode 100644 tpl/tplimpl/template.go
 rename tpl/{ => tplimpl}/template_ast_transformers.go (99%)
 rename tpl/{ => tplimpl}/template_ast_transformers_test.go (99%)
 rename tpl/{ => tplimpl}/template_embedded.go (99%)
 rename tpl/{ => tplimpl}/template_func_truncate.go (99%)
 rename tpl/{ => tplimpl}/template_func_truncate_test.go (99%)
 rename tpl/{ => tplimpl}/template_funcs.go (99%)
 rename tpl/{ => tplimpl}/template_funcs_test.go (99%)
 rename tpl/{ => tplimpl}/template_resources.go (99%)
 rename tpl/{ => tplimpl}/template_resources_test.go (99%)
 rename tpl/{ => tplimpl}/template_test.go (97%)
 delete mode 100644 tplapi/template.go

diff --git a/deps/deps.go b/deps/deps.go
index 39a3d31a4..de1b955cb 100644
--- a/deps/deps.go
+++ b/deps/deps.go
@@ -8,7 +8,7 @@ import (
 	"github.com/spf13/hugo/config"
 	"github.com/spf13/hugo/helpers"
 	"github.com/spf13/hugo/hugofs"
-	"github.com/spf13/hugo/tplapi"
+	"github.com/spf13/hugo/tpl"
 	jww "github.com/spf13/jwalterweatherman"
 )
 
@@ -20,7 +20,7 @@ type Deps struct {
 	Log *jww.Notepad `json:"-"`
 
 	// The templates to use.
-	Tmpl tplapi.Template `json:"-"`
+	Tmpl tpl.Template `json:"-"`
 
 	// The file systems to use.
 	Fs *hugofs.Fs `json:"-"`
@@ -40,7 +40,7 @@ type Deps struct {
 	Language *helpers.Language
 
 	templateProvider ResourceProvider
-	WithTemplate     func(templ tplapi.Template) error `json:"-"`
+	WithTemplate     func(templ tpl.Template) error `json:"-"`
 
 	translationProvider ResourceProvider
 }
@@ -147,7 +147,7 @@ type DepsCfg struct {
 
 	// Template handling.
 	TemplateProvider ResourceProvider
-	WithTemplate     func(templ tplapi.Template) error
+	WithTemplate     func(templ tpl.Template) error
 
 	// i18n handling.
 	TranslationProvider ResourceProvider
diff --git a/hugolib/embedded_shortcodes_test.go b/hugolib/embedded_shortcodes_test.go
index 513767eb4..a98ca1369 100644
--- a/hugolib/embedded_shortcodes_test.go
+++ b/hugolib/embedded_shortcodes_test.go
@@ -25,7 +25,7 @@ import (
 	"github.com/spf13/hugo/deps"
 
 	"github.com/spf13/hugo/helpers"
-	"github.com/spf13/hugo/tplapi"
+	"github.com/spf13/hugo/tpl"
 	"github.com/stretchr/testify/require"
 )
 
@@ -335,7 +335,7 @@ func TestShortcodeTweet(t *testing.T) {
 			th      = testHelper{cfg}
 		)
 
-		withTemplate := func(templ tplapi.Template) error {
+		withTemplate := func(templ tpl.Template) error {
 			templ.Funcs(tweetFuncMap)
 			return nil
 		}
@@ -390,7 +390,7 @@ func TestShortcodeInstagram(t *testing.T) {
 			th      = testHelper{cfg}
 		)
 
-		withTemplate := func(templ tplapi.Template) error {
+		withTemplate := func(templ tpl.Template) error {
 			templ.Funcs(instagramFuncMap)
 			return nil
 		}
diff --git a/hugolib/hugo_sites.go b/hugolib/hugo_sites.go
index f0feec23e..3cbe4fa90 100644
--- a/hugolib/hugo_sites.go
+++ b/hugolib/hugo_sites.go
@@ -24,7 +24,7 @@ import (
 
 	"github.com/spf13/hugo/i18n"
 	"github.com/spf13/hugo/tpl"
-	"github.com/spf13/hugo/tplapi"
+	"github.com/spf13/hugo/tpl/tplimpl"
 )
 
 // HugoSites represents the sites to build. Each site represents a language.
@@ -72,7 +72,7 @@ func newHugoSites(cfg deps.DepsCfg, sites ...*Site) (*HugoSites, error) {
 
 func applyDepsIfNeeded(cfg deps.DepsCfg, sites ...*Site) error {
 	if cfg.TemplateProvider == nil {
-		cfg.TemplateProvider = tpl.DefaultTemplateProvider
+		cfg.TemplateProvider = tplimpl.DefaultTemplateProvider
 	}
 
 	if cfg.TranslationProvider == nil {
@@ -121,8 +121,8 @@ func NewHugoSites(cfg deps.DepsCfg) (*HugoSites, error) {
 	return newHugoSites(cfg, sites...)
 }
 
-func (s *Site) withSiteTemplates(withTemplates ...func(templ tplapi.Template) error) func(templ tplapi.Template) error {
-	return func(templ tplapi.Template) error {
+func (s *Site) withSiteTemplates(withTemplates ...func(templ tpl.Template) error) func(templ tpl.Template) error {
+	return func(templ tpl.Template) error {
 		templ.LoadTemplates(s.absLayoutDir())
 		if s.hasTheme() {
 			templ.LoadTemplatesWithPrefix(s.absThemeDir()+"/layouts", "theme")
@@ -191,7 +191,7 @@ func (h *HugoSites) reset() {
 		h.Sites[i] = s.reset()
 	}
 
-	tpl.ResetCaches()
+	tplimpl.ResetCaches()
 }
 
 func (h *HugoSites) createSitesFromConfig() error {
@@ -553,7 +553,7 @@ func (h *HugoSites) Pages() Pages {
 	return h.Sites[0].AllPages
 }
 
-func handleShortcodes(p *Page, t tplapi.Template, rawContentCopy []byte) ([]byte, error) {
+func handleShortcodes(p *Page, t tpl.Template, rawContentCopy []byte) ([]byte, error) {
 	if len(p.contentShortCodes) > 0 {
 		p.s.Log.DEBUG.Printf("Replace %d shortcodes in %q", len(p.contentShortCodes), p.BaseFileName())
 		shortcodes, err := executeShortcodeFuncMap(p.contentShortCodes)
diff --git a/hugolib/shortcode.go b/hugolib/shortcode.go
index 4ce6df7e9..775c57e8c 100644
--- a/hugolib/shortcode.go
+++ b/hugolib/shortcode.go
@@ -26,7 +26,7 @@ import (
 
 	bp "github.com/spf13/hugo/bufferpool"
 	"github.com/spf13/hugo/helpers"
-	"github.com/spf13/hugo/tplapi"
+	"github.com/spf13/hugo/tpl"
 )
 
 // ShortcodeWithPage is the "." context in a shortcode template.
@@ -541,7 +541,7 @@ func replaceShortcodeTokens(source []byte, prefix string, replacements map[strin
 	return source, nil
 }
 
-func getShortcodeTemplate(name string, t tplapi.Template) *template.Template {
+func getShortcodeTemplate(name string, t tpl.Template) *template.Template {
 	if x := t.Lookup("shortcodes/" + name + ".html"); x != nil {
 		return x
 	}
diff --git a/hugolib/shortcode_test.go b/hugolib/shortcode_test.go
index b1f28d53b..665e3a944 100644
--- a/hugolib/shortcode_test.go
+++ b/hugolib/shortcode_test.go
@@ -25,12 +25,12 @@ import (
 	"github.com/spf13/hugo/deps"
 	"github.com/spf13/hugo/helpers"
 	"github.com/spf13/hugo/source"
-	"github.com/spf13/hugo/tplapi"
+	"github.com/spf13/hugo/tpl"
 	"github.com/stretchr/testify/require"
 )
 
 // TODO(bep) remove
-func pageFromString(in, filename string, withTemplate ...func(templ tplapi.Template) error) (*Page, error) {
+func pageFromString(in, filename string, withTemplate ...func(templ tpl.Template) error) (*Page, error) {
 	s := newTestSite(nil)
 	if len(withTemplate) > 0 {
 		// Have to create a new site
@@ -47,11 +47,11 @@ func pageFromString(in, filename string, withTemplate ...func(templ tplapi.Templ
 	return s.NewPageFrom(strings.NewReader(in), filename)
 }
 
-func CheckShortCodeMatch(t *testing.T, input, expected string, withTemplate func(templ tplapi.Template) error) {
+func CheckShortCodeMatch(t *testing.T, input, expected string, withTemplate func(templ tpl.Template) error) {
 	CheckShortCodeMatchAndError(t, input, expected, withTemplate, false)
 }
 
-func CheckShortCodeMatchAndError(t *testing.T, input, expected string, withTemplate func(templ tplapi.Template) error, expectError bool) {
+func CheckShortCodeMatchAndError(t *testing.T, input, expected string, withTemplate func(templ tpl.Template) error, expectError bool) {
 
 	cfg, fs := newTestCfg()
 
@@ -100,7 +100,7 @@ func TestNonSC(t *testing.T) {
 // Issue #929
 func TestHyphenatedSC(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("hyphenated-video.html", `Playing Video {{ .Get 0 }}`)
 		return nil
 	}
@@ -111,7 +111,7 @@ func TestHyphenatedSC(t *testing.T) {
 // Issue #1753
 func TestNoTrailingNewline(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("a.html", `{{ .Get 0 }}`)
 		return nil
 	}
@@ -121,7 +121,7 @@ func TestNoTrailingNewline(t *testing.T) {
 
 func TestPositionalParamSC(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("video.html", `Playing Video {{ .Get 0 }}`)
 		return nil
 	}
@@ -135,7 +135,7 @@ func TestPositionalParamSC(t *testing.T) {
 
 func TestPositionalParamIndexOutOfBounds(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("video.html", `Playing Video {{ .Get 1 }}`)
 		return nil
 	}
@@ -146,7 +146,7 @@ func TestPositionalParamIndexOutOfBounds(t *testing.T) {
 
 func TestNamedParamSC(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("img.html", `<img{{ with .Get "src" }} src="{{.}}"{{end}}{{with .Get "class"}} class="{{.}}"{{end}}>`)
 		return nil
 	}
@@ -161,7 +161,7 @@ func TestNamedParamSC(t *testing.T) {
 // Issue #2294
 func TestNestedNamedMissingParam(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("acc.html", `<div class="acc">{{ .Inner }}</div>`)
 		tem.AddInternalShortcode("div.html", `<div {{with .Get "class"}} class="{{ . }}"{{ end }}>{{ .Inner }}</div>`)
 		tem.AddInternalShortcode("div2.html", `<div {{with .Get 0}} class="{{ . }}"{{ end }}>{{ .Inner }}</div>`)
@@ -174,7 +174,7 @@ func TestNestedNamedMissingParam(t *testing.T) {
 
 func TestIsNamedParamsSC(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("byposition.html", `<div id="{{ .Get 0 }}">`)
 		tem.AddInternalShortcode("byname.html", `<div id="{{ .Get "id" }}">`)
 		tem.AddInternalShortcode("ifnamedparams.html", `<div id="{{ if .IsNamedParams }}{{ .Get "id" }}{{ else }}{{ .Get 0 }}{{end}}">`)
@@ -190,7 +190,7 @@ func TestIsNamedParamsSC(t *testing.T) {
 
 func TestInnerSC(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("inside.html", `<div{{with .Get "class"}} class="{{.}}"{{end}}>{{ .Inner }}</div>`)
 		return nil
 	}
@@ -201,7 +201,7 @@ func TestInnerSC(t *testing.T) {
 
 func TestInnerSCWithMarkdown(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("inside.html", `<div{{with .Get "class"}} class="{{.}}"{{end}}>{{ .Inner }}</div>`)
 		return nil
 	}
@@ -215,7 +215,7 @@ func TestInnerSCWithMarkdown(t *testing.T) {
 
 func TestInnerSCWithAndWithoutMarkdown(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("inside.html", `<div{{with .Get "class"}} class="{{.}}"{{end}}>{{ .Inner }}</div>`)
 		return nil
 	}
@@ -246,7 +246,7 @@ func TestEmbeddedSC(t *testing.T) {
 
 func TestNestedSC(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("scn1.html", `<div>Outer, inner is {{ .Inner }}</div>`)
 		tem.AddInternalShortcode("scn2.html", `<div>SC2</div>`)
 		return nil
@@ -258,7 +258,7 @@ func TestNestedSC(t *testing.T) {
 
 func TestNestedComplexSC(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("row.html", `-row-{{ .Inner}}-rowStop-`)
 		tem.AddInternalShortcode("column.html", `-col-{{.Inner    }}-colStop-`)
 		tem.AddInternalShortcode("aside.html", `-aside-{{    .Inner  }}-asideStop-`)
@@ -274,7 +274,7 @@ func TestNestedComplexSC(t *testing.T) {
 
 func TestParentShortcode(t *testing.T) {
 	t.Parallel()
-	wt := func(tem tplapi.Template) error {
+	wt := func(tem tpl.Template) error {
 		tem.AddInternalShortcode("r1.html", `1: {{ .Get "pr1" }} {{ .Inner }}`)
 		tem.AddInternalShortcode("r2.html", `2: {{ .Parent.Get "pr1" }}{{ .Get "pr2" }} {{ .Inner }}`)
 		tem.AddInternalShortcode("r3.html", `3: {{ .Parent.Parent.Get "pr1" }}{{ .Parent.Get "pr2" }}{{ .Get "pr3" }} {{ .Inner }}`)
@@ -342,7 +342,7 @@ func TestExtractShortcodes(t *testing.T) {
 			fmt.Sprintf("Hello %sworld%s. And that's it.", testScPlaceholderRegexp, testScPlaceholderRegexp), ""},
 	} {
 
-		p, _ := pageFromString(simplePage, "simple.md", func(templ tplapi.Template) error {
+		p, _ := pageFromString(simplePage, "simple.md", func(templ tpl.Template) error {
 			templ.AddInternalShortcode("tag.html", `tag`)
 			templ.AddInternalShortcode("sc1.html", `sc1`)
 			templ.AddInternalShortcode("sc2.html", `sc2`)
@@ -514,7 +514,7 @@ tags:
 		sources[i] = source.ByteSource{Name: filepath.FromSlash(test.contentPath), Content: []byte(test.content)}
 	}
 
-	addTemplates := func(templ tplapi.Template) error {
+	addTemplates := func(templ tpl.Template) error {
 		templ.AddTemplate("_default/single.html", "{{.Content}}")
 
 		templ.AddInternalShortcode("b.html", `b`)
diff --git a/hugolib/site.go b/hugolib/site.go
index bd0156849..a5555d0e4 100644
--- a/hugolib/site.go
+++ b/hugolib/site.go
@@ -40,7 +40,7 @@ import (
 	"github.com/spf13/hugo/parser"
 	"github.com/spf13/hugo/source"
 	"github.com/spf13/hugo/target"
-	"github.com/spf13/hugo/tplapi"
+	"github.com/spf13/hugo/tpl"
 	"github.com/spf13/hugo/transform"
 	"github.com/spf13/nitro"
 	"github.com/spf13/viper"
@@ -149,7 +149,7 @@ func NewSite(cfg deps.DepsCfg) (*Site, error) {
 // NewSiteDefaultLang creates a new site in the default language.
 // The site will have a template system loaded and ready to use.
 // Note: This is mainly used in single site tests.
-func NewSiteDefaultLang(withTemplate ...func(templ tplapi.Template) error) (*Site, error) {
+func NewSiteDefaultLang(withTemplate ...func(templ tpl.Template) error) (*Site, error) {
 	v := viper.New()
 	loadDefaultSettingsFor(v)
 	return newSiteForLang(helpers.NewDefaultLanguage(v), withTemplate...)
@@ -158,15 +158,15 @@ func NewSiteDefaultLang(withTemplate ...func(templ tplapi.Template) error) (*Sit
 // NewEnglishSite creates a new site in English language.
 // The site will have a template system loaded and ready to use.
 // Note: This is mainly used in single site tests.
-func NewEnglishSite(withTemplate ...func(templ tplapi.Template) error) (*Site, error) {
+func NewEnglishSite(withTemplate ...func(templ tpl.Template) error) (*Site, error) {
 	v := viper.New()
 	loadDefaultSettingsFor(v)
 	return newSiteForLang(helpers.NewLanguage("en", v), withTemplate...)
 }
 
 // newSiteForLang creates a new site in the given language.
-func newSiteForLang(lang *helpers.Language, withTemplate ...func(templ tplapi.Template) error) (*Site, error) {
-	withTemplates := func(templ tplapi.Template) error {
+func newSiteForLang(lang *helpers.Language, withTemplate ...func(templ tpl.Template) error) (*Site, error) {
+	withTemplates := func(templ tpl.Template) error {
 		for _, wt := range withTemplate {
 			if err := wt(templ); err != nil {
 				return err
diff --git a/hugolib/sitemap_test.go b/hugolib/sitemap_test.go
index 8bbcb487b..daefde524 100644
--- a/hugolib/sitemap_test.go
+++ b/hugolib/sitemap_test.go
@@ -19,7 +19,7 @@ import (
 	"reflect"
 
 	"github.com/spf13/hugo/deps"
-	"github.com/spf13/hugo/tplapi"
+	"github.com/spf13/hugo/tpl"
 )
 
 const sitemapTemplate = `<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
@@ -48,7 +48,7 @@ func doTestSitemapOutput(t *testing.T, internal bool) {
 	depsCfg := deps.DepsCfg{Fs: fs, Cfg: cfg}
 
 	if !internal {
-		depsCfg.WithTemplate = func(templ tplapi.Template) error {
+		depsCfg.WithTemplate = func(templ tpl.Template) error {
 			templ.AddTemplate("sitemap.xml", sitemapTemplate)
 			return nil
 		}
diff --git a/hugolib/testhelpers_test.go b/hugolib/testhelpers_test.go
index 33e78e121..f0fcd9530 100644
--- a/hugolib/testhelpers_test.go
+++ b/hugolib/testhelpers_test.go
@@ -7,7 +7,7 @@ import (
 	"github.com/spf13/hugo/deps"
 	"github.com/spf13/hugo/helpers"
 	"github.com/spf13/hugo/source"
-	"github.com/spf13/hugo/tplapi"
+	"github.com/spf13/hugo/tpl"
 	"github.com/spf13/viper"
 
 	"io/ioutil"
@@ -66,9 +66,9 @@ func newDebugLogger() *jww.Notepad {
 	return jww.NewNotepad(jww.LevelDebug, jww.LevelError, os.Stdout, ioutil.Discard, "", log.Ldate|log.Ltime)
 }
 
-func createWithTemplateFromNameValues(additionalTemplates ...string) func(templ tplapi.Template) error {
+func createWithTemplateFromNameValues(additionalTemplates ...string) func(templ tpl.Template) error {
 
-	return func(templ tplapi.Template) error {
+	return func(templ tpl.Template) error {
 		for i := 0; i < len(additionalTemplates); i += 2 {
 			err := templ.AddTemplate(additionalTemplates[i], additionalTemplates[i+1])
 			if err != nil {
diff --git a/tpl/template.go b/tpl/template.go
index 9a6364d5a..aaf7fc8c7 100644
--- a/tpl/template.go
+++ b/tpl/template.go
@@ -1,575 +1,27 @@
-// Copyright 2016 The Hugo Authors. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
 package tpl
 
 import (
-	"fmt"
 	"html/template"
 	"io"
-	"os"
-	"path/filepath"
-	"strings"
-
-	"sync"
-
-	"github.com/eknkc/amber"
-	"github.com/spf13/afero"
-	bp "github.com/spf13/hugo/bufferpool"
-	"github.com/spf13/hugo/deps"
-	"github.com/spf13/hugo/helpers"
-	"github.com/yosssi/ace"
 )
 
-// TODO(bep) globals get rid of the rest of the jww.ERR etc.
-
-// Protecting global map access (Amber)
-var amberMu sync.Mutex
-
-type templateErr struct {
-	name string
-	err  error
-}
-
-type GoHTMLTemplate struct {
-	*template.Template
-
-	clone *template.Template
-
-	// a separate storage for the overlays created from cloned master templates.
-	// note: No mutex protection, so we add these in one Go routine, then just read.
-	overlays map[string]*template.Template
-
-	errors []*templateErr
-
-	funcster *templateFuncster
-
-	amberFuncMap template.FuncMap
-
-	*deps.Deps
-}
-
-type TemplateProvider struct{}
-
-var DefaultTemplateProvider *TemplateProvider
-
-// Update updates the Hugo Template System in the provided Deps.
-// with all the additional features, templates & functions
-func (*TemplateProvider) Update(deps *deps.Deps) error {
-	// TODO(bep) check that this isn't called too many times.
-	tmpl := &GoHTMLTemplate{
-		Template: template.New(""),
-		overlays: make(map[string]*template.Template),
-		errors:   make([]*templateErr, 0),
-		Deps:     deps,
-	}
-
-	deps.Tmpl = tmpl
-
-	tmpl.initFuncs(deps)
-
-	tmpl.LoadEmbedded()
-
-	if deps.WithTemplate != nil {
-		err := deps.WithTemplate(tmpl)
-		if err != nil {
-			tmpl.errors = append(tmpl.errors, &templateErr{"init", err})
-		}
-
-	}
-
-	tmpl.MarkReady()
-
-	return nil
-
-}
-
-// Clone clones
-func (*TemplateProvider) Clone(d *deps.Deps) error {
-
-	t := d.Tmpl.(*GoHTMLTemplate)
-
-	// 1. Clone the clone with new template funcs
-	// 2. Clone any overlays with new template funcs
-
-	tmpl := &GoHTMLTemplate{
-		Template: template.Must(t.Template.Clone()),
-		overlays: make(map[string]*template.Template),
-		errors:   make([]*templateErr, 0),
-		Deps:     d,
-	}
-
-	d.Tmpl = tmpl
-	tmpl.initFuncs(d)
-
-	for k, v := range t.overlays {
-		vc := template.Must(v.Clone())
-		// The extra lookup is a workaround, see
-		// * https://github.com/golang/go/issues/16101
-		// * https://github.com/spf13/hugo/issues/2549
-		vc = vc.Lookup(vc.Name())
-		vc.Funcs(tmpl.funcster.funcMap)
-		tmpl.overlays[k] = vc
-	}
-
-	tmpl.MarkReady()
-
-	return nil
-}
-
-func (t *GoHTMLTemplate) initFuncs(d *deps.Deps) {
-
-	t.funcster = newTemplateFuncster(d)
-
-	// The URL funcs in the funcMap is somewhat language dependent,
-	// so we need to wait until the language and site config is loaded.
-	t.funcster.initFuncMap()
-
-	t.amberFuncMap = template.FuncMap{}
-
-	amberMu.Lock()
-	for k, v := range amber.FuncMap {
-		t.amberFuncMap[k] = v
-	}
-
-	for k, v := range t.funcster.funcMap {
-		t.amberFuncMap[k] = v
-		// Hacky, but we need to make sure that the func names are in the global map.
-		amber.FuncMap[k] = func() string {
-			panic("should never be invoked")
-		}
-	}
-	amberMu.Unlock()
-
-}
-
-func (t *GoHTMLTemplate) Funcs(funcMap template.FuncMap) {
-	t.Template.Funcs(funcMap)
-}
-
-func (t *GoHTMLTemplate) Partial(name string, contextList ...interface{}) template.HTML {
-	if strings.HasPrefix("partials/", name) {
-		name = name[8:]
-	}
-	var context interface{}
-
-	if len(contextList) == 0 {
-		context = nil
-	} else {
-		context = contextList[0]
-	}
-	return t.ExecuteTemplateToHTML(context, "partials/"+name, "theme/partials/"+name)
-}
-
-func (t *GoHTMLTemplate) executeTemplate(context interface{}, w io.Writer, layouts ...string) {
-	var worked bool
-	for _, layout := range layouts {
-		templ := t.Lookup(layout)
-		if templ == nil {
-			layout += ".html"
-			templ = t.Lookup(layout)
-		}
-
-		if templ != nil {
-			if err := templ.Execute(w, context); err != nil {
-				helpers.DistinctErrorLog.Println(layout, err)
-			}
-			worked = true
-			break
-		}
-	}
-	if !worked {
-		t.Log.ERROR.Println("Unable to render", layouts)
-		t.Log.ERROR.Println("Expecting to find a template in either the theme/layouts or /layouts in one of the following relative locations", layouts)
-	}
-}
-
-func (t *GoHTMLTemplate) ExecuteTemplateToHTML(context interface{}, layouts ...string) template.HTML {
-	b := bp.GetBuffer()
-	defer bp.PutBuffer(b)
-	t.executeTemplate(context, b, layouts...)
-	return template.HTML(b.String())
-}
-
-func (t *GoHTMLTemplate) Lookup(name string) *template.Template {
-
-	if templ := t.Template.Lookup(name); templ != nil {
-		return templ
-	}
-
-	if t.overlays != nil {
-		if templ, ok := t.overlays[name]; ok {
-			return templ
-		}
-	}
-
-	// The clone is used for the non-renderable HTML pages (p.IsRenderable == false) that is parsed
-	// as Go templates late in the build process.
-	if t.clone != nil {
-		if templ := t.clone.Lookup(name); templ != nil {
-			return templ
-		}
-	}
-
-	return nil
-
-}
-
-func (t *GoHTMLTemplate) GetClone() *template.Template {
-	return t.clone
-}
-
-func (t *GoHTMLTemplate) LoadEmbedded() {
-	t.EmbedShortcodes()
-	t.EmbedTemplates()
-}
-
-// MarkReady marks the template as "ready for execution". No changes allowed
-// after this is set.
-func (t *GoHTMLTemplate) MarkReady() {
-	if t.clone == nil {
-		t.clone = template.Must(t.Template.Clone())
-	}
-}
-
-func (t *GoHTMLTemplate) checkState() {
-	if t.clone != nil {
-		panic("template is cloned and cannot be modfified")
-	}
-}
-
-func (t *GoHTMLTemplate) AddInternalTemplate(prefix, name, tpl string) error {
-	if prefix != "" {
-		return t.AddTemplate("_internal/"+prefix+"/"+name, tpl)
-	}
-	return t.AddTemplate("_internal/"+name, tpl)
-}
-
-func (t *GoHTMLTemplate) AddInternalShortcode(name, content string) error {
-	return t.AddInternalTemplate("shortcodes", name, content)
-}
-
-func (t *GoHTMLTemplate) AddTemplate(name, tpl string) error {
-	t.checkState()
-	templ, err := t.New(name).Parse(tpl)
-	if err != nil {
-		t.errors = append(t.errors, &templateErr{name: name, err: err})
-		return err
-	}
-	if err := applyTemplateTransformers(templ); err != nil {
-		return err
-	}
-
-	return nil
-}
-
-func (t *GoHTMLTemplate) AddTemplateFileWithMaster(name, overlayFilename, masterFilename string) error {
-
-	// There is currently no known way to associate a cloned template with an existing one.
-	// This funky master/overlay design will hopefully improve in a future version of Go.
-	//
-	// Simplicity is hard.
-	//
-	// Until then we'll have to live with this hackery.
-	//
-	// See https://github.com/golang/go/issues/14285
-	//
-	// So, to do minimum amount of changes to get this to work:
-	//
-	// 1. Lookup or Parse the master
-	// 2. Parse and store the overlay in a separate map
-
-	masterTpl := t.Lookup(masterFilename)
-
-	if masterTpl == nil {
-		b, err := afero.ReadFile(t.Fs.Source, masterFilename)
-		if err != nil {
-			return err
-		}
-		masterTpl, err = t.New(masterFilename).Parse(string(b))
-
-		if err != nil {
-			// TODO(bep) Add a method that does this
-			t.errors = append(t.errors, &templateErr{name: name, err: err})
-			return err
-		}
-	}
-
-	b, err := afero.ReadFile(t.Fs.Source, overlayFilename)
-	if err != nil {
-		return err
-	}
-
-	overlayTpl, err := template.Must(masterTpl.Clone()).Parse(string(b))
-	if err != nil {
-		t.errors = append(t.errors, &templateErr{name: name, err: err})
-	} else {
-		// The extra lookup is a workaround, see
-		// * https://github.com/golang/go/issues/16101
-		// * https://github.com/spf13/hugo/issues/2549
-		overlayTpl = overlayTpl.Lookup(overlayTpl.Name())
-		if err := applyTemplateTransformers(overlayTpl); err != nil {
-			return err
-		}
-		t.overlays[name] = overlayTpl
-	}
-
-	return err
-}
-
-func (t *GoHTMLTemplate) AddAceTemplate(name, basePath, innerPath string, baseContent, innerContent []byte) error {
-	t.checkState()
-	var base, inner *ace.File
-	name = name[:len(name)-len(filepath.Ext(innerPath))] + ".html"
-
-	// Fixes issue #1178
-	basePath = strings.Replace(basePath, "\\", "/", -1)
-	innerPath = strings.Replace(innerPath, "\\", "/", -1)
-
-	if basePath != "" {
-		base = ace.NewFile(basePath, baseContent)
-		inner = ace.NewFile(innerPath, innerContent)
-	} else {
-		base = ace.NewFile(innerPath, innerContent)
-		inner = ace.NewFile("", []byte{})
-	}
-	parsed, err := ace.ParseSource(ace.NewSource(base, inner, []*ace.File{}), nil)
-	if err != nil {
-		t.errors = append(t.errors, &templateErr{name: name, err: err})
-		return err
-	}
-	templ, err := ace.CompileResultWithTemplate(t.New(name), parsed, nil)
-	if err != nil {
-		t.errors = append(t.errors, &templateErr{name: name, err: err})
-		return err
-	}
-	return applyTemplateTransformers(templ)
-}
-
-func (t *GoHTMLTemplate) AddTemplateFile(name, baseTemplatePath, path string) error {
-	t.checkState()
-	// get the suffix and switch on that
-	ext := filepath.Ext(path)
-	switch ext {
-	case ".amber":
-		templateName := strings.TrimSuffix(name, filepath.Ext(name)) + ".html"
-		b, err := afero.ReadFile(t.Fs.Source, path)
-
-		if err != nil {
-			return err
-		}
-
-		amberMu.Lock()
-		templ, err := t.CompileAmberWithTemplate(b, path, t.New(templateName))
-		amberMu.Unlock()
-		if err != nil {
-			return err
-		}
-
-		return applyTemplateTransformers(templ)
-	case ".ace":
-		var innerContent, baseContent []byte
-		innerContent, err := afero.ReadFile(t.Fs.Source, path)
-
-		if err != nil {
-			return err
-		}
-
-		if baseTemplatePath != "" {
-			baseContent, err = afero.ReadFile(t.Fs.Source, baseTemplatePath)
-			if err != nil {
-				return err
-			}
-		}
-
-		return t.AddAceTemplate(name, baseTemplatePath, path, baseContent, innerContent)
-	default:
-
-		if baseTemplatePath != "" {
-			return t.AddTemplateFileWithMaster(name, path, baseTemplatePath)
-		}
-
-		b, err := afero.ReadFile(t.Fs.Source, path)
-
-		if err != nil {
-			return err
-		}
-
-		t.Log.DEBUG.Printf("Add template file from path %s", path)
-
-		return t.AddTemplate(name, string(b))
-	}
-
-}
-
-func (t *GoHTMLTemplate) GenerateTemplateNameFrom(base, path string) string {
-	name, _ := filepath.Rel(base, path)
-	return filepath.ToSlash(name)
-}
-
-func isDotFile(path string) bool {
-	return filepath.Base(path)[0] == '.'
-}
-
-func isBackupFile(path string) bool {
-	return path[len(path)-1] == '~'
-}
-
-const baseFileBase = "baseof"
-
-var aceTemplateInnerMarkers = [][]byte{[]byte("= content")}
-var goTemplateInnerMarkers = [][]byte{[]byte("{{define"), []byte("{{ define")}
-
-func isBaseTemplate(path string) bool {
-	return strings.Contains(path, baseFileBase)
-}
-
-func (t *GoHTMLTemplate) loadTemplates(absPath string, prefix string) {
-	t.Log.DEBUG.Printf("Load templates from path %q prefix %q", absPath, prefix)
-	walker := func(path string, fi os.FileInfo, err error) error {
-		if err != nil {
-			return nil
-		}
-		t.Log.DEBUG.Println("Template path", path)
-		if fi.Mode()&os.ModeSymlink == os.ModeSymlink {
-			link, err := filepath.EvalSymlinks(absPath)
-			if err != nil {
-				t.Log.ERROR.Printf("Cannot read symbolic link '%s', error was: %s", absPath, err)
-				return nil
-			}
-			linkfi, err := t.Fs.Source.Stat(link)
-			if err != nil {
-				t.Log.ERROR.Printf("Cannot stat '%s', error was: %s", link, err)
-				return nil
-			}
-			if !linkfi.Mode().IsRegular() {
-				t.Log.ERROR.Printf("Symbolic links for directories not supported, skipping '%s'", absPath)
-			}
-			return nil
-		}
-
-		if !fi.IsDir() {
-			if isDotFile(path) || isBackupFile(path) || isBaseTemplate(path) {
-				return nil
-			}
-
-			tplName := t.GenerateTemplateNameFrom(absPath, path)
-
-			if prefix != "" {
-				tplName = strings.Trim(prefix, "/") + "/" + tplName
-			}
-
-			var baseTemplatePath string
-
-			// Ace and Go templates may have both a base and inner template.
-			pathDir := filepath.Dir(path)
-			if filepath.Ext(path) != ".amber" && !strings.HasSuffix(pathDir, "partials") && !strings.HasSuffix(pathDir, "shortcodes") {
-
-				innerMarkers := goTemplateInnerMarkers
-				baseFileName := fmt.Sprintf("%s.html", baseFileBase)
-
-				if filepath.Ext(path) == ".ace" {
-					innerMarkers = aceTemplateInnerMarkers
-					baseFileName = fmt.Sprintf("%s.ace", baseFileBase)
-				}
-
-				// This may be a view that shouldn't have base template
-				// Have to look inside it to make sure
-				needsBase, err := helpers.FileContainsAny(path, innerMarkers, t.Fs.Source)
-				if err != nil {
-					return err
-				}
-				if needsBase {
-
-					layoutDir := t.PathSpec.GetLayoutDirPath()
-					currBaseFilename := fmt.Sprintf("%s-%s", helpers.Filename(path), baseFileName)
-					templateDir := filepath.Dir(path)
-					themeDir := filepath.Join(t.PathSpec.GetThemeDir())
-					relativeThemeLayoutsDir := filepath.Join(t.PathSpec.GetRelativeThemeDir(), "layouts")
-
-					var baseTemplatedDir string
-
-					if strings.HasPrefix(templateDir, relativeThemeLayoutsDir) {
-						baseTemplatedDir = strings.TrimPrefix(templateDir, relativeThemeLayoutsDir)
-					} else {
-						baseTemplatedDir = strings.TrimPrefix(templateDir, layoutDir)
-					}
-
-					baseTemplatedDir = strings.TrimPrefix(baseTemplatedDir, helpers.FilePathSeparator)
-
-					// Look for base template in the follwing order:
-					//   1. <current-path>/<template-name>-baseof.<suffix>, e.g. list-baseof.<suffix>.
-					//   2. <current-path>/baseof.<suffix>
-					//   3. _default/<template-name>-baseof.<suffix>, e.g. list-baseof.<suffix>.
-					//   4. _default/baseof.<suffix>
-					// For each of the steps above, it will first look in the project, then, if theme is set,
-					// in the theme's layouts folder.
-
-					pairsToCheck := [][]string{
-						[]string{baseTemplatedDir, currBaseFilename},
-						[]string{baseTemplatedDir, baseFileName},
-						[]string{"_default", currBaseFilename},
-						[]string{"_default", baseFileName},
-					}
-
-				Loop:
-					for _, pair := range pairsToCheck {
-						pathsToCheck := basePathsToCheck(pair, layoutDir, themeDir)
-						for _, pathToCheck := range pathsToCheck {
-							if ok, err := helpers.Exists(pathToCheck, t.Fs.Source); err == nil && ok {
-								baseTemplatePath = pathToCheck
-								break Loop
-							}
-						}
-					}
-				}
-			}
-
-			if err := t.AddTemplateFile(tplName, baseTemplatePath, path); err != nil {
-				t.Log.ERROR.Printf("Failed to add template %s in path %s: %s", tplName, path, err)
-			}
-
-		}
-		return nil
-	}
-	if err := helpers.SymbolicWalk(t.Fs.Source, absPath, walker); err != nil {
-		t.Log.ERROR.Printf("Failed to load templates: %s", err)
-	}
-}
-
-func basePathsToCheck(path []string, layoutDir, themeDir string) []string {
-	// Always look in the project.
-	pathsToCheck := []string{filepath.Join((append([]string{layoutDir}, path...))...)}
-
-	// May have a theme
-	if themeDir != "" {
-		pathsToCheck = append(pathsToCheck, filepath.Join((append([]string{themeDir, "layouts"}, path...))...))
-	}
-
-	return pathsToCheck
-
-}
-
-func (t *GoHTMLTemplate) LoadTemplatesWithPrefix(absPath string, prefix string) {
-	t.loadTemplates(absPath, prefix)
-}
-
-func (t *GoHTMLTemplate) LoadTemplates(absPath string) {
-	t.loadTemplates(absPath, "")
-}
-
-func (t *GoHTMLTemplate) PrintErrors() {
-	for i, e := range t.errors {
-		t.Log.ERROR.Println(i, ":", e.err)
-	}
+// TODO(bep) make smaller
+type Template interface {
+	ExecuteTemplate(wr io.Writer, name string, data interface{}) error
+	ExecuteTemplateToHTML(context interface{}, layouts ...string) template.HTML
+	Lookup(name string) *template.Template
+	Templates() []*template.Template
+	New(name string) *template.Template
+	GetClone() *template.Template
+	LoadTemplates(absPath string)
+	LoadTemplatesWithPrefix(absPath, prefix string)
+	AddTemplate(name, tpl string) error
+	AddTemplateFileWithMaster(name, overlayFilename, masterFilename string) error
+	AddAceTemplate(name, basePath, innerPath string, baseContent, innerContent []byte) error
+	AddInternalTemplate(prefix, name, tpl string) error
+	AddInternalShortcode(name, tpl string) error
+	Partial(name string, contextList ...interface{}) template.HTML
+	PrintErrors()
+	Funcs(funcMap template.FuncMap)
+	MarkReady()
 }
diff --git a/tpl/amber_compiler.go b/tpl/tplimpl/amber_compiler.go
similarity index 98%
rename from tpl/amber_compiler.go
rename to tpl/tplimpl/amber_compiler.go
index 4477f6ac0..252c39ffb 100644
--- a/tpl/amber_compiler.go
+++ b/tpl/tplimpl/amber_compiler.go
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tpl
+package tplimpl
 
 import (
 	"html/template"
diff --git a/tpl/reflect_helpers.go b/tpl/tplimpl/reflect_helpers.go
similarity index 96%
rename from tpl/reflect_helpers.go
rename to tpl/tplimpl/reflect_helpers.go
index f2ce722a2..7463683fc 100644
--- a/tpl/reflect_helpers.go
+++ b/tpl/tplimpl/reflect_helpers.go
@@ -1,4 +1,4 @@
-// Copyright 2016 The Hugo Authors. All rights reserved.
+// Copyright 2017 The Hugo Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tpl
+package tplimpl
 
 import (
 	"reflect"
diff --git a/tpl/tplimpl/template.go b/tpl/tplimpl/template.go
new file mode 100644
index 000000000..cf1fc5620
--- /dev/null
+++ b/tpl/tplimpl/template.go
@@ -0,0 +1,575 @@
+// Copyright 2016 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tplimpl
+
+import (
+	"fmt"
+	"html/template"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"sync"
+
+	"github.com/eknkc/amber"
+	"github.com/spf13/afero"
+	bp "github.com/spf13/hugo/bufferpool"
+	"github.com/spf13/hugo/deps"
+	"github.com/spf13/hugo/helpers"
+	"github.com/yosssi/ace"
+)
+
+// TODO(bep) globals get rid of the rest of the jww.ERR etc.
+
+// Protecting global map access (Amber)
+var amberMu sync.Mutex
+
+type templateErr struct {
+	name string
+	err  error
+}
+
+type GoHTMLTemplate struct {
+	*template.Template
+
+	clone *template.Template
+
+	// a separate storage for the overlays created from cloned master templates.
+	// note: No mutex protection, so we add these in one Go routine, then just read.
+	overlays map[string]*template.Template
+
+	errors []*templateErr
+
+	funcster *templateFuncster
+
+	amberFuncMap template.FuncMap
+
+	*deps.Deps
+}
+
+type TemplateProvider struct{}
+
+var DefaultTemplateProvider *TemplateProvider
+
+// Update updates the Hugo Template System in the provided Deps.
+// with all the additional features, templates & functions
+func (*TemplateProvider) Update(deps *deps.Deps) error {
+	// TODO(bep) check that this isn't called too many times.
+	tmpl := &GoHTMLTemplate{
+		Template: template.New(""),
+		overlays: make(map[string]*template.Template),
+		errors:   make([]*templateErr, 0),
+		Deps:     deps,
+	}
+
+	deps.Tmpl = tmpl
+
+	tmpl.initFuncs(deps)
+
+	tmpl.LoadEmbedded()
+
+	if deps.WithTemplate != nil {
+		err := deps.WithTemplate(tmpl)
+		if err != nil {
+			tmpl.errors = append(tmpl.errors, &templateErr{"init", err})
+		}
+
+	}
+
+	tmpl.MarkReady()
+
+	return nil
+
+}
+
+// Clone clones
+func (*TemplateProvider) Clone(d *deps.Deps) error {
+
+	t := d.Tmpl.(*GoHTMLTemplate)
+
+	// 1. Clone the clone with new template funcs
+	// 2. Clone any overlays with new template funcs
+
+	tmpl := &GoHTMLTemplate{
+		Template: template.Must(t.Template.Clone()),
+		overlays: make(map[string]*template.Template),
+		errors:   make([]*templateErr, 0),
+		Deps:     d,
+	}
+
+	d.Tmpl = tmpl
+	tmpl.initFuncs(d)
+
+	for k, v := range t.overlays {
+		vc := template.Must(v.Clone())
+		// The extra lookup is a workaround, see
+		// * https://github.com/golang/go/issues/16101
+		// * https://github.com/spf13/hugo/issues/2549
+		vc = vc.Lookup(vc.Name())
+		vc.Funcs(tmpl.funcster.funcMap)
+		tmpl.overlays[k] = vc
+	}
+
+	tmpl.MarkReady()
+
+	return nil
+}
+
+func (t *GoHTMLTemplate) initFuncs(d *deps.Deps) {
+
+	t.funcster = newTemplateFuncster(d)
+
+	// The URL funcs in the funcMap is somewhat language dependent,
+	// so we need to wait until the language and site config is loaded.
+	t.funcster.initFuncMap()
+
+	t.amberFuncMap = template.FuncMap{}
+
+	amberMu.Lock()
+	for k, v := range amber.FuncMap {
+		t.amberFuncMap[k] = v
+	}
+
+	for k, v := range t.funcster.funcMap {
+		t.amberFuncMap[k] = v
+		// Hacky, but we need to make sure that the func names are in the global map.
+		amber.FuncMap[k] = func() string {
+			panic("should never be invoked")
+		}
+	}
+	amberMu.Unlock()
+
+}
+
+func (t *GoHTMLTemplate) Funcs(funcMap template.FuncMap) {
+	t.Template.Funcs(funcMap)
+}
+
+func (t *GoHTMLTemplate) Partial(name string, contextList ...interface{}) template.HTML {
+	if strings.HasPrefix("partials/", name) {
+		name = name[8:]
+	}
+	var context interface{}
+
+	if len(contextList) == 0 {
+		context = nil
+	} else {
+		context = contextList[0]
+	}
+	return t.ExecuteTemplateToHTML(context, "partials/"+name, "theme/partials/"+name)
+}
+
+func (t *GoHTMLTemplate) executeTemplate(context interface{}, w io.Writer, layouts ...string) {
+	var worked bool
+	for _, layout := range layouts {
+		templ := t.Lookup(layout)
+		if templ == nil {
+			layout += ".html"
+			templ = t.Lookup(layout)
+		}
+
+		if templ != nil {
+			if err := templ.Execute(w, context); err != nil {
+				helpers.DistinctErrorLog.Println(layout, err)
+			}
+			worked = true
+			break
+		}
+	}
+	if !worked {
+		t.Log.ERROR.Println("Unable to render", layouts)
+		t.Log.ERROR.Println("Expecting to find a template in either the theme/layouts or /layouts in one of the following relative locations", layouts)
+	}
+}
+
+func (t *GoHTMLTemplate) ExecuteTemplateToHTML(context interface{}, layouts ...string) template.HTML {
+	b := bp.GetBuffer()
+	defer bp.PutBuffer(b)
+	t.executeTemplate(context, b, layouts...)
+	return template.HTML(b.String())
+}
+
+func (t *GoHTMLTemplate) Lookup(name string) *template.Template {
+
+	if templ := t.Template.Lookup(name); templ != nil {
+		return templ
+	}
+
+	if t.overlays != nil {
+		if templ, ok := t.overlays[name]; ok {
+			return templ
+		}
+	}
+
+	// The clone is used for the non-renderable HTML pages (p.IsRenderable == false) that is parsed
+	// as Go templates late in the build process.
+	if t.clone != nil {
+		if templ := t.clone.Lookup(name); templ != nil {
+			return templ
+		}
+	}
+
+	return nil
+
+}
+
+func (t *GoHTMLTemplate) GetClone() *template.Template {
+	return t.clone
+}
+
+func (t *GoHTMLTemplate) LoadEmbedded() {
+	t.EmbedShortcodes()
+	t.EmbedTemplates()
+}
+
+// MarkReady marks the template as "ready for execution". No changes allowed
+// after this is set.
+func (t *GoHTMLTemplate) MarkReady() {
+	if t.clone == nil {
+		t.clone = template.Must(t.Template.Clone())
+	}
+}
+
+func (t *GoHTMLTemplate) checkState() {
+	if t.clone != nil {
+		panic("template is cloned and cannot be modfified")
+	}
+}
+
+func (t *GoHTMLTemplate) AddInternalTemplate(prefix, name, tpl string) error {
+	if prefix != "" {
+		return t.AddTemplate("_internal/"+prefix+"/"+name, tpl)
+	}
+	return t.AddTemplate("_internal/"+name, tpl)
+}
+
+func (t *GoHTMLTemplate) AddInternalShortcode(name, content string) error {
+	return t.AddInternalTemplate("shortcodes", name, content)
+}
+
+func (t *GoHTMLTemplate) AddTemplate(name, tpl string) error {
+	t.checkState()
+	templ, err := t.New(name).Parse(tpl)
+	if err != nil {
+		t.errors = append(t.errors, &templateErr{name: name, err: err})
+		return err
+	}
+	if err := applyTemplateTransformers(templ); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (t *GoHTMLTemplate) AddTemplateFileWithMaster(name, overlayFilename, masterFilename string) error {
+
+	// There is currently no known way to associate a cloned template with an existing one.
+	// This funky master/overlay design will hopefully improve in a future version of Go.
+	//
+	// Simplicity is hard.
+	//
+	// Until then we'll have to live with this hackery.
+	//
+	// See https://github.com/golang/go/issues/14285
+	//
+	// So, to do minimum amount of changes to get this to work:
+	//
+	// 1. Lookup or Parse the master
+	// 2. Parse and store the overlay in a separate map
+
+	masterTpl := t.Lookup(masterFilename)
+
+	if masterTpl == nil {
+		b, err := afero.ReadFile(t.Fs.Source, masterFilename)
+		if err != nil {
+			return err
+		}
+		masterTpl, err = t.New(masterFilename).Parse(string(b))
+
+		if err != nil {
+			// TODO(bep) Add a method that does this
+			t.errors = append(t.errors, &templateErr{name: name, err: err})
+			return err
+		}
+	}
+
+	b, err := afero.ReadFile(t.Fs.Source, overlayFilename)
+	if err != nil {
+		return err
+	}
+
+	overlayTpl, err := template.Must(masterTpl.Clone()).Parse(string(b))
+	if err != nil {
+		t.errors = append(t.errors, &templateErr{name: name, err: err})
+	} else {
+		// The extra lookup is a workaround, see
+		// * https://github.com/golang/go/issues/16101
+		// * https://github.com/spf13/hugo/issues/2549
+		overlayTpl = overlayTpl.Lookup(overlayTpl.Name())
+		if err := applyTemplateTransformers(overlayTpl); err != nil {
+			return err
+		}
+		t.overlays[name] = overlayTpl
+	}
+
+	return err
+}
+
+func (t *GoHTMLTemplate) AddAceTemplate(name, basePath, innerPath string, baseContent, innerContent []byte) error {
+	t.checkState()
+	var base, inner *ace.File
+	name = name[:len(name)-len(filepath.Ext(innerPath))] + ".html"
+
+	// Fixes issue #1178
+	basePath = strings.Replace(basePath, "\\", "/", -1)
+	innerPath = strings.Replace(innerPath, "\\", "/", -1)
+
+	if basePath != "" {
+		base = ace.NewFile(basePath, baseContent)
+		inner = ace.NewFile(innerPath, innerContent)
+	} else {
+		base = ace.NewFile(innerPath, innerContent)
+		inner = ace.NewFile("", []byte{})
+	}
+	parsed, err := ace.ParseSource(ace.NewSource(base, inner, []*ace.File{}), nil)
+	if err != nil {
+		t.errors = append(t.errors, &templateErr{name: name, err: err})
+		return err
+	}
+	templ, err := ace.CompileResultWithTemplate(t.New(name), parsed, nil)
+	if err != nil {
+		t.errors = append(t.errors, &templateErr{name: name, err: err})
+		return err
+	}
+	return applyTemplateTransformers(templ)
+}
+
+func (t *GoHTMLTemplate) AddTemplateFile(name, baseTemplatePath, path string) error {
+	t.checkState()
+	// get the suffix and switch on that
+	ext := filepath.Ext(path)
+	switch ext {
+	case ".amber":
+		templateName := strings.TrimSuffix(name, filepath.Ext(name)) + ".html"
+		b, err := afero.ReadFile(t.Fs.Source, path)
+
+		if err != nil {
+			return err
+		}
+
+		amberMu.Lock()
+		templ, err := t.CompileAmberWithTemplate(b, path, t.New(templateName))
+		amberMu.Unlock()
+		if err != nil {
+			return err
+		}
+
+		return applyTemplateTransformers(templ)
+	case ".ace":
+		var innerContent, baseContent []byte
+		innerContent, err := afero.ReadFile(t.Fs.Source, path)
+
+		if err != nil {
+			return err
+		}
+
+		if baseTemplatePath != "" {
+			baseContent, err = afero.ReadFile(t.Fs.Source, baseTemplatePath)
+			if err != nil {
+				return err
+			}
+		}
+
+		return t.AddAceTemplate(name, baseTemplatePath, path, baseContent, innerContent)
+	default:
+
+		if baseTemplatePath != "" {
+			return t.AddTemplateFileWithMaster(name, path, baseTemplatePath)
+		}
+
+		b, err := afero.ReadFile(t.Fs.Source, path)
+
+		if err != nil {
+			return err
+		}
+
+		t.Log.DEBUG.Printf("Add template file from path %s", path)
+
+		return t.AddTemplate(name, string(b))
+	}
+
+}
+
+func (t *GoHTMLTemplate) GenerateTemplateNameFrom(base, path string) string {
+	name, _ := filepath.Rel(base, path)
+	return filepath.ToSlash(name)
+}
+
+func isDotFile(path string) bool {
+	return filepath.Base(path)[0] == '.'
+}
+
+func isBackupFile(path string) bool {
+	return path[len(path)-1] == '~'
+}
+
+const baseFileBase = "baseof"
+
+var aceTemplateInnerMarkers = [][]byte{[]byte("= content")}
+var goTemplateInnerMarkers = [][]byte{[]byte("{{define"), []byte("{{ define")}
+
+func isBaseTemplate(path string) bool {
+	return strings.Contains(path, baseFileBase)
+}
+
+func (t *GoHTMLTemplate) loadTemplates(absPath string, prefix string) {
+	t.Log.DEBUG.Printf("Load templates from path %q prefix %q", absPath, prefix)
+	walker := func(path string, fi os.FileInfo, err error) error {
+		if err != nil {
+			return nil
+		}
+		t.Log.DEBUG.Println("Template path", path)
+		if fi.Mode()&os.ModeSymlink == os.ModeSymlink {
+			link, err := filepath.EvalSymlinks(absPath)
+			if err != nil {
+				t.Log.ERROR.Printf("Cannot read symbolic link '%s', error was: %s", absPath, err)
+				return nil
+			}
+			linkfi, err := t.Fs.Source.Stat(link)
+			if err != nil {
+				t.Log.ERROR.Printf("Cannot stat '%s', error was: %s", link, err)
+				return nil
+			}
+			if !linkfi.Mode().IsRegular() {
+				t.Log.ERROR.Printf("Symbolic links for directories not supported, skipping '%s'", absPath)
+			}
+			return nil
+		}
+
+		if !fi.IsDir() {
+			if isDotFile(path) || isBackupFile(path) || isBaseTemplate(path) {
+				return nil
+			}
+
+			tplName := t.GenerateTemplateNameFrom(absPath, path)
+
+			if prefix != "" {
+				tplName = strings.Trim(prefix, "/") + "/" + tplName
+			}
+
+			var baseTemplatePath string
+
+			// Ace and Go templates may have both a base and inner template.
+			pathDir := filepath.Dir(path)
+			if filepath.Ext(path) != ".amber" && !strings.HasSuffix(pathDir, "partials") && !strings.HasSuffix(pathDir, "shortcodes") {
+
+				innerMarkers := goTemplateInnerMarkers
+				baseFileName := fmt.Sprintf("%s.html", baseFileBase)
+
+				if filepath.Ext(path) == ".ace" {
+					innerMarkers = aceTemplateInnerMarkers
+					baseFileName = fmt.Sprintf("%s.ace", baseFileBase)
+				}
+
+				// This may be a view that shouldn't have base template
+				// Have to look inside it to make sure
+				needsBase, err := helpers.FileContainsAny(path, innerMarkers, t.Fs.Source)
+				if err != nil {
+					return err
+				}
+				if needsBase {
+
+					layoutDir := t.PathSpec.GetLayoutDirPath()
+					currBaseFilename := fmt.Sprintf("%s-%s", helpers.Filename(path), baseFileName)
+					templateDir := filepath.Dir(path)
+					themeDir := filepath.Join(t.PathSpec.GetThemeDir())
+					relativeThemeLayoutsDir := filepath.Join(t.PathSpec.GetRelativeThemeDir(), "layouts")
+
+					var baseTemplatedDir string
+
+					if strings.HasPrefix(templateDir, relativeThemeLayoutsDir) {
+						baseTemplatedDir = strings.TrimPrefix(templateDir, relativeThemeLayoutsDir)
+					} else {
+						baseTemplatedDir = strings.TrimPrefix(templateDir, layoutDir)
+					}
+
+					baseTemplatedDir = strings.TrimPrefix(baseTemplatedDir, helpers.FilePathSeparator)
+
+					// Look for base template in the follwing order:
+					//   1. <current-path>/<template-name>-baseof.<suffix>, e.g. list-baseof.<suffix>.
+					//   2. <current-path>/baseof.<suffix>
+					//   3. _default/<template-name>-baseof.<suffix>, e.g. list-baseof.<suffix>.
+					//   4. _default/baseof.<suffix>
+					// For each of the steps above, it will first look in the project, then, if theme is set,
+					// in the theme's layouts folder.
+
+					pairsToCheck := [][]string{
+						[]string{baseTemplatedDir, currBaseFilename},
+						[]string{baseTemplatedDir, baseFileName},
+						[]string{"_default", currBaseFilename},
+						[]string{"_default", baseFileName},
+					}
+
+				Loop:
+					for _, pair := range pairsToCheck {
+						pathsToCheck := basePathsToCheck(pair, layoutDir, themeDir)
+						for _, pathToCheck := range pathsToCheck {
+							if ok, err := helpers.Exists(pathToCheck, t.Fs.Source); err == nil && ok {
+								baseTemplatePath = pathToCheck
+								break Loop
+							}
+						}
+					}
+				}
+			}
+
+			if err := t.AddTemplateFile(tplName, baseTemplatePath, path); err != nil {
+				t.Log.ERROR.Printf("Failed to add template %s in path %s: %s", tplName, path, err)
+			}
+
+		}
+		return nil
+	}
+	if err := helpers.SymbolicWalk(t.Fs.Source, absPath, walker); err != nil {
+		t.Log.ERROR.Printf("Failed to load templates: %s", err)
+	}
+}
+
+func basePathsToCheck(path []string, layoutDir, themeDir string) []string {
+	// Always look in the project.
+	pathsToCheck := []string{filepath.Join((append([]string{layoutDir}, path...))...)}
+
+	// May have a theme
+	if themeDir != "" {
+		pathsToCheck = append(pathsToCheck, filepath.Join((append([]string{themeDir, "layouts"}, path...))...))
+	}
+
+	return pathsToCheck
+
+}
+
+func (t *GoHTMLTemplate) LoadTemplatesWithPrefix(absPath string, prefix string) {
+	t.loadTemplates(absPath, prefix)
+}
+
+func (t *GoHTMLTemplate) LoadTemplates(absPath string) {
+	t.loadTemplates(absPath, "")
+}
+
+func (t *GoHTMLTemplate) PrintErrors() {
+	for i, e := range t.errors {
+		t.Log.ERROR.Println(i, ":", e.err)
+	}
+}
diff --git a/tpl/template_ast_transformers.go b/tpl/tplimpl/template_ast_transformers.go
similarity index 99%
rename from tpl/template_ast_transformers.go
rename to tpl/tplimpl/template_ast_transformers.go
index 19b772add..68090497b 100644
--- a/tpl/template_ast_transformers.go
+++ b/tpl/tplimpl/template_ast_transformers.go
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tpl
+package tplimpl
 
 import (
 	"errors"
diff --git a/tpl/template_ast_transformers_test.go b/tpl/tplimpl/template_ast_transformers_test.go
similarity index 99%
rename from tpl/template_ast_transformers_test.go
rename to tpl/tplimpl/template_ast_transformers_test.go
index 43d78284c..048d52fee 100644
--- a/tpl/template_ast_transformers_test.go
+++ b/tpl/tplimpl/template_ast_transformers_test.go
@@ -10,7 +10,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
-package tpl
+package tplimpl
 
 import (
 	"bytes"
diff --git a/tpl/template_embedded.go b/tpl/tplimpl/template_embedded.go
similarity index 99%
rename from tpl/template_embedded.go
rename to tpl/tplimpl/template_embedded.go
index f782a31e9..50397b28c 100644
--- a/tpl/template_embedded.go
+++ b/tpl/tplimpl/template_embedded.go
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tpl
+package tplimpl
 
 type Tmpl struct {
 	Name string
diff --git a/tpl/template_func_truncate.go b/tpl/tplimpl/template_func_truncate.go
similarity index 99%
rename from tpl/template_func_truncate.go
rename to tpl/tplimpl/template_func_truncate.go
index b5886edae..d4bb63272 100644
--- a/tpl/template_func_truncate.go
+++ b/tpl/tplimpl/template_func_truncate.go
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tpl
+package tplimpl
 
 import (
 	"errors"
diff --git a/tpl/template_func_truncate_test.go b/tpl/tplimpl/template_func_truncate_test.go
similarity index 99%
rename from tpl/template_func_truncate_test.go
rename to tpl/tplimpl/template_func_truncate_test.go
index 9213c6faa..9c4beecff 100644
--- a/tpl/template_func_truncate_test.go
+++ b/tpl/tplimpl/template_func_truncate_test.go
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tpl
+package tplimpl
 
 import (
 	"html/template"
diff --git a/tpl/template_funcs.go b/tpl/tplimpl/template_funcs.go
similarity index 99%
rename from tpl/template_funcs.go
rename to tpl/tplimpl/template_funcs.go
index 9777bf619..dae621ac3 100644
--- a/tpl/template_funcs.go
+++ b/tpl/tplimpl/template_funcs.go
@@ -13,7 +13,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tpl
+package tplimpl
 
 import (
 	"bytes"
diff --git a/tpl/template_funcs_test.go b/tpl/tplimpl/template_funcs_test.go
similarity index 99%
rename from tpl/template_funcs_test.go
rename to tpl/tplimpl/template_funcs_test.go
index 35214b649..0fba97bd3 100644
--- a/tpl/template_funcs_test.go
+++ b/tpl/tplimpl/template_funcs_test.go
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tpl
+package tplimpl
 
 import (
 	"bytes"
@@ -31,7 +31,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/spf13/hugo/tplapi"
+	"github.com/spf13/hugo/tpl"
 
 	"github.com/spf13/hugo/deps"
 	"github.com/spf13/hugo/helpers"
@@ -273,7 +273,7 @@ urlize: bat-man
 	v.Set("CurrentContentLanguage", helpers.NewLanguage("en", v))
 
 	config := newDepsConfig(v)
-	config.WithTemplate = func(templ tplapi.Template) error {
+	config.WithTemplate = func(templ tpl.Template) error {
 		if _, err := templ.New("test").Parse(in); err != nil {
 			t.Fatal("Got error on parse", err)
 		}
@@ -2862,7 +2862,7 @@ func TestPartialCached(t *testing.T) {
 
 		config := newDepsConfig(viper.New())
 
-		config.WithTemplate = func(templ tplapi.Template) error {
+		config.WithTemplate = func(templ tpl.Template) error {
 			err := templ.AddTemplate("testroot", tmp)
 			if err != nil {
 				return err
@@ -2901,7 +2901,7 @@ func TestPartialCached(t *testing.T) {
 
 func BenchmarkPartial(b *testing.B) {
 	config := newDepsConfig(viper.New())
-	config.WithTemplate = func(templ tplapi.Template) error {
+	config.WithTemplate = func(templ tpl.Template) error {
 		err := templ.AddTemplate("testroot", `{{ partial "bench1" . }}`)
 		if err != nil {
 			return err
@@ -2932,7 +2932,7 @@ func BenchmarkPartial(b *testing.B) {
 
 func BenchmarkPartialCached(b *testing.B) {
 	config := newDepsConfig(viper.New())
-	config.WithTemplate = func(templ tplapi.Template) error {
+	config.WithTemplate = func(templ tpl.Template) error {
 		err := templ.AddTemplate("testroot", `{{ partialCached "bench1" . }}`)
 		if err != nil {
 			return err
@@ -2978,7 +2978,7 @@ func newTestFuncsterWithViper(v *viper.Viper) *templateFuncster {
 
 func newTestTemplate(t *testing.T, name, template string) *template.Template {
 	config := newDepsConfig(viper.New())
-	config.WithTemplate = func(templ tplapi.Template) error {
+	config.WithTemplate = func(templ tpl.Template) error {
 		err := templ.AddTemplate(name, template)
 		if err != nil {
 			return err
diff --git a/tpl/template_resources.go b/tpl/tplimpl/template_resources.go
similarity index 99%
rename from tpl/template_resources.go
rename to tpl/tplimpl/template_resources.go
index bb1b11eb3..2b3d7120c 100644
--- a/tpl/template_resources.go
+++ b/tpl/tplimpl/template_resources.go
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tpl
+package tplimpl
 
 import (
 	"bytes"
diff --git a/tpl/template_resources_test.go b/tpl/tplimpl/template_resources_test.go
similarity index 99%
rename from tpl/template_resources_test.go
rename to tpl/tplimpl/template_resources_test.go
index 82764977f..8a9f62659 100644
--- a/tpl/template_resources_test.go
+++ b/tpl/tplimpl/template_resources_test.go
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tpl
+package tplimpl
 
 import (
 	"bytes"
diff --git a/tpl/template_test.go b/tpl/tplimpl/template_test.go
similarity index 97%
rename from tpl/template_test.go
rename to tpl/tplimpl/template_test.go
index 5bb6d89d3..08bcab1a7 100644
--- a/tpl/template_test.go
+++ b/tpl/tplimpl/template_test.go
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tpl
+package tplimpl
 
 import (
 	"bytes"
@@ -27,7 +27,7 @@ import (
 	"github.com/spf13/afero"
 	"github.com/spf13/hugo/deps"
 
-	"github.com/spf13/hugo/tplapi"
+	"github.com/spf13/hugo/tpl"
 	"github.com/spf13/viper"
 	"github.com/stretchr/testify/require"
 )
@@ -74,7 +74,7 @@ html lang=en
 			d := "DATA"
 
 			config := newDepsConfig(viper.New())
-			config.WithTemplate = func(templ tplapi.Template) error {
+			config.WithTemplate = func(templ tpl.Template) error {
 				return templ.AddAceTemplate("mytemplate.ace", basePath, innerPath,
 					[]byte(this.baseContent), []byte(this.innerContent))
 			}
@@ -144,7 +144,7 @@ func TestAddTemplateFileWithMaster(t *testing.T) {
 		finalTplName := "tp"
 
 		config := newDepsConfig(viper.New())
-		config.WithTemplate = func(templ tplapi.Template) error {
+		config.WithTemplate = func(templ tpl.Template) error {
 
 			err := templ.AddTemplateFileWithMaster(finalTplName, overlayTplName, masterTplName)
 
@@ -284,7 +284,7 @@ func TestTplGoFuzzReports(t *testing.T) {
 
 		config := newDepsConfig(viper.New())
 
-		config.WithTemplate = func(templ tplapi.Template) error {
+		config.WithTemplate = func(templ tpl.Template) error {
 			return templ.AddTemplate("fuzz", this.data)
 		}
 
diff --git a/tplapi/template.go b/tplapi/template.go
deleted file mode 100644
index 58bc5ecf9..000000000
--- a/tplapi/template.go
+++ /dev/null
@@ -1,28 +0,0 @@
-package tplapi
-
-import (
-	"html/template"
-	"io"
-)
-
-// TODO(bep) make smaller
-// TODO(bep) consider putting this into /tpl and the implementation in /tpl/tplimpl or something
-type Template interface {
-	ExecuteTemplate(wr io.Writer, name string, data interface{}) error
-	ExecuteTemplateToHTML(context interface{}, layouts ...string) template.HTML
-	Lookup(name string) *template.Template
-	Templates() []*template.Template
-	New(name string) *template.Template
-	GetClone() *template.Template
-	LoadTemplates(absPath string)
-	LoadTemplatesWithPrefix(absPath, prefix string)
-	AddTemplate(name, tpl string) error
-	AddTemplateFileWithMaster(name, overlayFilename, masterFilename string) error
-	AddAceTemplate(name, basePath, innerPath string, baseContent, innerContent []byte) error
-	AddInternalTemplate(prefix, name, tpl string) error
-	AddInternalShortcode(name, tpl string) error
-	Partial(name string, contextList ...interface{}) template.HTML
-	PrintErrors()
-	Funcs(funcMap template.FuncMap)
-	MarkReady()
-}