code review 13864044: go.tools/oracle: change -mode argument into subcommand.

go.tools/oracle: change -mode argument into subcommand.

e.g. "oracle callgraph <package>"

Also: simplified error handling.
Eliminated oracle.errorf because it prepends "file:line:col: "
to the error message so the main function can't safely prepend "Error: ".
The position wasn't interesting though: it was just -pos, more or less.

[adonovan, 2013-09-24 20:03:53]

Hello crawshaw@google.com (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/go.tools

[Dominik Honnef, 2013-09-24 22:34:14]

LGTM on the emacs front.

[r, 2013-09-25 04:32:20]

LGTM but instead of errors.New i'd just use fmt.Errorf everywhere.

[adonovan, 2013-09-25 18:34:42]

*** Submitted as
https://code.google.com/p/go/source/detail?r=4c5f46cc7b9d&repo=tools ***

go.tools/oracle: change -mode argument into subcommand.

e.g. "oracle callgraph <package>"

Also: simplified error handling.
Eliminated oracle.errorf because it prepends "file:line:col: "
to the error message so the main function can't safely prepend "Error: ".
The position wasn't interesting though: it was just -pos, more or less.

R=crawshaw, dominik.honnef, r
CC=golang-dev
https://codereview.appspot.com/13864044