go/doc: first steps towards cleaning up go/doc

- separated exported data structures from doc reader
  by extracting all exported data structures into doc.go
  and moving the implementation into reader.go
- added missing documentation comments
- no API or semantic changes (but moved positions of
  PackageDoc.Doc and TypeDoc.Decl field up for consistency)
- runs all tests

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5527063

src/buildscript_darwin_386.sh

@@ -460,7 +460,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/darwin_386/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.8
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/darwin_386/go/doc.a
 

src/buildscript_darwin_amd64.sh

@@ -459,7 +459,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/darwin_amd64/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.6
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/darwin_amd64/go/doc.a
 

src/buildscript_freebsd_386.sh

@@ -460,7 +460,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/freebsd_386/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.8
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/freebsd_386/go/doc.a
 

src/buildscript_freebsd_amd64.sh

@@ -459,7 +459,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/freebsd_amd64/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.6
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/freebsd_amd64/go/doc.a
 

src/buildscript_linux_386.sh

@@ -460,7 +460,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/linux_386/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.8
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/linux_386/go/doc.a
 

src/buildscript_linux_amd64.sh

@@ -459,7 +459,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/linux_amd64/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.6
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/linux_amd64/go/doc.a
 

src/buildscript_linux_arm.sh

@@ -463,7 +463,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/linux_arm/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-5g -o "$WORK"/go/doc/_obj/_go_.5 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+5g -o "$WORK"/go/doc/_obj/_go_.5 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.5
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/linux_arm/go/doc.a
 

src/buildscript_netbsd_386.sh

@@ -460,7 +460,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/netbsd_386/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.8
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/netbsd_386/go/doc.a
 

src/buildscript_netbsd_amd64.sh

@@ -459,7 +459,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/netbsd_amd64/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.6
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/netbsd_amd64/go/doc.a
 

src/buildscript_openbsd_386.sh

@@ -460,7 +460,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/openbsd_386/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.8
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/openbsd_386/go/doc.a
 

src/buildscript_openbsd_amd64.sh

@@ -459,7 +459,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/openbsd_amd64/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.6
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/openbsd_amd64/go/doc.a
 

src/buildscript_plan9_386.sh

@@ -460,7 +460,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/plan9_386/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.8
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/plan9_386/go/doc.a
 

src/buildscript_windows_386.sh

@@ -462,7 +462,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/windows_386/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+8g -o "$WORK"/go/doc/_obj/_go_.8 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.8
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/windows_386/go/doc.a
 

src/buildscript_windows_amd64.sh

@@ -461,7 +461,7 @@ cp "$WORK"/text/template.a "$GOROOT"/pkg/windows_amd64/text/template.a
 
 mkdir -p "$WORK"/go/doc/_obj/
 cd "$GOROOT"/src/pkg/go/doc
-6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go
+6g -o "$WORK"/go/doc/_obj/_go_.6 -p go/doc -I "$WORK" ./comment.go ./doc.go ./example.go ./exports.go ./filter.go ./reader.go
 gopack grc "$WORK"/go/doc.a "$WORK"/go/doc/_obj/_go_.6
 cp "$WORK"/go/doc.a "$GOROOT"/pkg/windows_amd64/go/doc.a
 

src/pkg/go/doc/Makefile

@@ -11,6 +11,7 @@ GOFILES=\
 	example.go\
 	exports.go\
 	filter.go\
+	reader.go\
 
 include ../../../Make.pkg