需要m4宏为任意文本追加边距

Question

假设我定义了一个m4宏FOOBAR，其中包含一段任意文本，可能包含逗号字符。请创建一个m4宏，添加5个空格的左边距

问题很简单(只需使用patsubst w/"^"正则表达式)，如果文本不包含任何逗号。但是我需要处理逗号

谢谢!

Answer 1

需要润色，但这是一个开始:

m4_divert(-1)
I changed the m4 quoting to use [<{}>]
m4_define(_spaces,[<{m4_format([<{%}>]$1[<{s}>],)}>])
m4_define(_indent,[<{m4_patsubst($1,[<{^}>],_spaces($2))}>])
m4_define(_Comma_and_Paren_Safe,[<{m4_patsubst([<{[<{Some. arbitrary text,with unbalanced parentheses like:
((()((((
and several commas ,,,, and a few, more , of those 
commas,,.
}>]}>],[<{,}>],[<{[<{,}>]}>])}>])

m4_divert(0)m4_dnl
_indent([<{_Comma_and_Paren_Safe}>],7)

示例运行(_m42是简单的m4包装脚本):

$ _m42 < ~/tmp/2v.STDIN.m4-margin.SatMay16.2052.190
       Some. arbitrary text,with unbalanced parentheses like:
       ((()((((
       and several commas ,,,, and a few, more , of those 
       commas,,.

Answer 2

比之前的尝试更简单:保存到宏FOOBAR -任意文本嵌套在四引号内以保护逗号的段落，和不平衡的括号:

m4_divert(-1)
m4_define(_spaces,[<{m4_format([<{%}>]$1[<{s}>],)}>])
m4_define(_indent,[<{m4_patsubst($1,[<{^}>],_spaces($2))}>])
--
Simpler than prior attempt: save arbitrary text paragraph nested inside
quadruple quote to protect commas, and unbalanced parentheses:
m4_define(FOOBAR,[<{[<{[<{[<{Some. arbitrary text,with unbalanced parentheses like:
((()((((
and several commas ,,,, and a few, more , of those
commas,,.
}>]}>] }>]}>])
m4_divert(0)m4_dnl
_indent(FOOBAR,15)

示例运行:

$ _m42 < ~/tmp/2v.STDIN.m4-margin.SatMay16.2052.190
               Some. arbitrary text,with unbalanced parentheses like:
               ((()((((
               and several commas ,,,, and a few, more , of those
               commas,,.