x/tools/present: Docs say 'h' key in the browser will toggle extra emphasis of any highlighted lines, seemingly not true.

[dmitshur]

What version of Go are you using (go version)?

go version go1.7.1 darwin/amd64

What operating system and processor architecture are you using (go env)?

$ go env
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/Dmitri/Dropbox/Work/2013/GoLanding:/Users/Dmitri/Dropbox/Work/2013/GoLand"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/tw/kgz4v2kn4n7d7ryg5k_z3dk40000gn/T/go-build653232358=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"

What did you do?

I read the documentation for present slide format at https://godoc.org/golang.org/x/tools/present.

It said:

Also, inside the displayed text a line that ends

// HL

will be highlighted in the display; the 'h' key in the browser will toggle extra emphasis of any highlighted lines.

What did you expect to see?

Pressing 'h' key in browser would have some effect on emphasis of highlighted lines.

What did you see instead?

Pressing 'h' key has no effect on emphasis of highlighted lines.

Looking at the code,

https://github.com/golang/tools/blob/b5358b5feea9734b97ff1e792ca6bc55170bc92a/cmd/present/static/slides.js#L408

It says 'H' hides the help text.

So something doesn't look right here. I don't know if the documentation is wrong, or if the implementation has a bug.

[ianlancetaylor]

CC @adg

[dmitshur]

So something doesn't look right here. I don't know if the documentation is wrong, or if the implementation has a bug.

I did some code archeology to find out. The earliest commit I found where the 'h' key in browser was mentioned was the very first commit where the present format is added. It was actually in talks subrepo before being moved to tools. It was commit golang/talks@a498aa1#diff-35e109b2aa892087b376d175ba51281dR93.

In that commit, I see no mention of 'h' key anywhere else except that one line of documentation.

Three years later, the 'h' key got mapped to hiding the help dialog in commit golang/tools@753a094.

My best guess is this original feature was documented but never implemented. So removing it from documentation is the most appropriate fix. Will send a CL.

[gopherbot]

Change https://golang.org/cl/143557 mentions this issue: present: remove mention of non-existing emphasis toggle