tree 3c8ba47d66ba2ba5d9d00675a1fb67de8b4ebd08
parent 49fb8cc10c2d61ebdf3829f42bba9bec7b0a7ff7
author Rob Pike <r@golang.org> 1441749492 -0700
committer Rob Pike <r@golang.org> 1441776491 +0000

text/template: provide a way to trim leading and trailing space between actions

Borrowing a suggestion from the issue listed below, we modify the lexer to
trim spaces at the beginning (end) of a block of text if the action immediately
before (after) is marked with a minus sign. To avoid parsing/lexing ambiguity,
we require an ASCII space between the minus sign and the rest of the action.
Thus:

	{{23 -}}
	<
	{{- 45}}

produces the output
	23<45

All the work is done in the lexer. The modification is invisible to the parser
or any outside package (except I guess for noticing some gaps in the input
if one tracks error positions). Thus it slips in without worry in text/template
and html/template both.

Fixes long-requested issue #9969.

Change-Id: I3774be650bfa6370cb993d0899aa669c211de7b2
Reviewed-on: https://go-review.googlesource.com/14391
Reviewed-by: Andrew Gerrand <adg@golang.org>