From d997d4078deb63ccc9a7a05d273617d63d7b3fc1 Mon Sep 17 00:00:00 2001
From: Evgeny Gagauz <evgenij.gagauz@gmail.com>
Date: Mon, 1 Aug 2016 23:37:00 +0300
Subject: [PATCH 1/3] Empty lines do not break options sections.
There are several reasons why an options section can be split by an
empty line, among them are:
- logically grouping;
- aesthetic reasons.
Such style is used, for example, in 'man' program.
An example:
Options:
--before-empty-lines An option before empty lines.
--after-empty-lines An option after empty lines.
---
docopt.cpp | 4 ++--
testcases.docopt | 18 ++++++++++++++++++
2 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/docopt.cpp b/docopt.cpp
index e875d2f..67d222d 100644
--- a/docopt.cpp
+++ b/docopt.cpp
@@ -168,8 +168,8 @@ static std::vector<std::string> parse_section(std::string const& name, std::stri
std::regex const re_section_pattern {
"(?:^|\\n)" // anchored at a linebreak (or start of string)
"("
- "[^\\n]*" + name + "[^\\n]*(?=\\n?)" // a line that contains the name
- "(?:\\n[ \\t].*?(?=\\n|$))*" // followed by any number of lines that are indented
+ "[^\\n]*" + name + "[^\\n]*(?=\\n?)" // a line that contains the section name
+ "(?:\\n+[ \\t].*?(?=\\n|$))*" // followed by any number of indented or empty lines
")",
std::regex::icase
};
diff --git a/testcases.docopt b/testcases.docopt
index efe9a07..3954d33 100644
--- a/testcases.docopt
+++ b/testcases.docopt
@@ -955,3 +955,21 @@ other options:
"""
$ prog --baz --egg
{"--foo": false, "--baz": true, "--bar": false, "--egg": true, "--spam": false}
+
+
+# An empty line must not break an options section.
+r"""
+Usage: prog [options]
+
+Options:
+ --before-empty-lines An option before empty lines.
+
+
+ --after-empty-lines An option after empty lines.
+"""
+
+$ prog --before-empty-lines
+{"--before-empty-lines": true, "--after-empty-lines": false}
+
+$ prog --after-empty-line
+{"--before-empty-lines": false, "--after-empty-lines": true}
From fb64b5c7c712a14e481eca2a3ce5b0b9fab71084 Mon Sep 17 00:00:00 2001
From: Evgeny Gagauz <evgenij.gagauz@gmail.com>
Date: Fri, 5 Aug 2016 00:48:14 +0300
Subject: [PATCH 2/3] Regex in parse_section() is aligned with proposal for
docopt.
The proposed changes for docopt can be found in the pull request
[339](https://github.com/docopt/docopt/pull/339).
---
docopt.cpp | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/docopt.cpp b/docopt.cpp
index 67d222d..554bcc2 100644
--- a/docopt.cpp
+++ b/docopt.cpp
@@ -161,16 +161,20 @@ std::vector<T*> flat_filter(Pattern& pattern) {
}
static std::vector<std::string> parse_section(std::string const& name, std::string const& source) {
+ // There is no a multiline strings concept in std::regex, therefore the symbols `^` and `$` match
+ // only once at the start and at the end of a string, even if this string contains new line
+ // characters. For this reason, following constructions are used instead:
+ // (?:^|\\n) - start of a line;
+ // (?=\\n|$) - end of a line.
// ECMAScript regex only has "?=" for a non-matching lookahead. In order to make sure we always have
// a newline to anchor our matching, we have to avoid matching the final newline of each grouping.
- // Therefore, our regex is adjusted from the docopt Python one to use ?= to match the newlines before
- // the following lines, rather than after.
std::regex const re_section_pattern {
- "(?:^|\\n)" // anchored at a linebreak (or start of string)
- "("
- "[^\\n]*" + name + "[^\\n]*(?=\\n?)" // a line that contains the section name
- "(?:\\n+[ \\t].*?(?=\\n|$))*" // followed by any number of indented or empty lines
- ")",
+ "(?:^|\\n)(" // A section begins at start of a line and consists of:
+ ".*" + name + ".*" // - a line that contains the section's name; and
+ "(?:" // - several
+ "\\n+[ \\t].*" // indented lines possibly separated by empty lines.
+ ")*"
+ ")(?=\\n|$)", // The section ends at the end of a line.
std::regex::icase
};
From 1c4b042c4ac0e37696ca608768cab94d21ea2e8f Mon Sep 17 00:00:00 2001
From: Evgeny Gagauz <evgenij.gagauz@gmail.com>
Date: Fri, 5 Aug 2016 02:31:01 +0300
Subject: [PATCH 3/3] Wildcards are repalced with `[^\\n]` as a workaround for
Boost.Regex.
The wildcard `.` matches any single character including the newline
character in Boost.Regex. So, `[^\\n]` construction is used instead.
---
docopt.cpp | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/docopt.cpp b/docopt.cpp
index 554bcc2..fcdc07e 100644
--- a/docopt.cpp
+++ b/docopt.cpp
@@ -166,15 +166,19 @@ static std::vector<std::string> parse_section(std::string const& name, std::stri
// characters. For this reason, following constructions are used instead:
// (?:^|\\n) - start of a line;
// (?=\\n|$) - end of a line.
+ //
// ECMAScript regex only has "?=" for a non-matching lookahead. In order to make sure we always have
// a newline to anchor our matching, we have to avoid matching the final newline of each grouping.
+ //
+ // The wildcard `.` matches any single character including the newline character in Boost.Regex. So,
+ // `[^\\n]` construction is used instead.
std::regex const re_section_pattern {
- "(?:^|\\n)(" // A section begins at start of a line and consists of:
- ".*" + name + ".*" // - a line that contains the section's name; and
- "(?:" // - several
- "\\n+[ \\t].*" // indented lines possibly separated by empty lines.
+ "(?:^|\\n)(" // A section begins at start of a line and consists of:
+ "[^\\n]*" + name + "[^\\n]*" // - a line that contains the section's name; and
+ "(?:" // - several
+ "\\n+[ \\t][^\\n]*" // indented lines possibly separated by empty lines.
")*"
- ")(?=\\n|$)", // The section ends at the end of a line.
+ ")(?=\\n|$)", // The section ends at the end of a line.
std::regex::icase
};