From e6ee26a03b79d0e8b658463bdb29349ca68e1460 Mon Sep 17 00:00:00 2001 From: Rob Pike Date: Tue, 8 Sep 2015 14:58:12 -0700 Subject: 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 --- src/text/template/parse/parse_test.go | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'src/text/template/parse/parse_test.go') diff --git a/src/text/template/parse/parse_test.go b/src/text/template/parse/parse_test.go index 200d50c194..28b5f7cb90 100644 --- a/src/text/template/parse/parse_test.go +++ b/src/text/template/parse/parse_test.go @@ -228,6 +228,13 @@ var parseTests = []parseTest{ `{{with .X}}"hello"{{end}}`}, {"with with else", "{{with .X}}hello{{else}}goodbye{{end}}", noError, `{{with .X}}"hello"{{else}}"goodbye"{{end}}`}, + // Trimming spaces. + {"trim left", "x \r\n\t{{- 3}}", noError, `"x"{{3}}`}, + {"trim right", "{{3 -}}\n\n\ty", noError, `{{3}}"y"`}, + {"trim left and right", "x \r\n\t{{- 3 -}}\n\n\ty", noError, `"x"{{3}}"y"`}, + {"comment trim left", "x \r\n\t{{- /* hi */}}", noError, `"x"`}, + {"comment trim right", "{{/* hi */ -}}\n\n\ty", noError, `"y"`}, + {"comment trim left and right", "x \r\n\t{{- /* */ -}}\n\n\ty", noError, `"x""y"`}, // Errors. {"unclosed action", "hello{{range", hasError, ""}, {"unmatched end", "{{end}}", hasError, ""}, -- cgit v1.3-5-g45d5