Don't include <regex> in header files

This reduces compilation time by ~15 seconds (CPU time).

Issue #4045.

3 files changed, 45 insertions, 38 deletions

diff --git a/src/libutil/url-parts.hh b/src/libutil/url-parts.hh
new file mode 100644
index 000000000..64e06cfbc
--- /dev/null
+++ b/src/libutil/url-parts.hh
@@ -0,0 +1,44 @@
+#pragma once
+
+#include <string>
+#include <regex>
+
+namespace nix {
+
+// URI stuff.
+const static std::string pctEncoded = "(?:%[0-9a-fA-F][0-9a-fA-F])";
+const static std::string schemeRegex = "(?:[a-z+.-]+)";
+const static std::string ipv6AddressRegex = "(?:\\[[0-9a-fA-F:]+\\])";
+const static std::string unreservedRegex = "(?:[a-zA-Z0-9-._~])";
+const static std::string subdelimsRegex = "(?:[!$&'\"()*+,;=])";
+const static std::string hostnameRegex = "(?:(?:" + unreservedRegex + "|" + pctEncoded + "|" + subdelimsRegex + ")*)";
+const static std::string hostRegex = "(?:" + ipv6AddressRegex + "|" + hostnameRegex + ")";
+const static std::string userRegex = "(?:(?:" + unreservedRegex + "|" + pctEncoded + "|" + subdelimsRegex + "|:)*)";
+const static std::string authorityRegex = "(?:" + userRegex + "@)?" + hostRegex + "(?::[0-9]+)?";
+const static std::string pcharRegex = "(?:" + unreservedRegex + "|" + pctEncoded + "|" + subdelimsRegex + "|[:@])";
+const static std::string queryRegex = "(?:" + pcharRegex + "|[/? \"])*";
+const static std::string segmentRegex = "(?:" + pcharRegex + "+)";
+const static std::string absPathRegex = "(?:(?:/" + segmentRegex + ")*/?)";
+const static std::string pathRegex = "(?:" + segmentRegex + "(?:/" + segmentRegex + ")*/?)";
+
+// A Git ref (i.e. branch or tag name).
+const static std::string refRegexS = "[a-zA-Z0-9][a-zA-Z0-9_.-]*"; // FIXME: check
+extern std::regex refRegex;
+
+// Instead of defining what a good Git Ref is, we define what a bad Git Ref is
+// This is because of the definition of a ref in refs.c in https://github.com/git/git
+// See tests/fetchGitRefs.sh for the full definition
+const static std::string badGitRefRegexS = "//|^[./]|/\\.|\\.\\.|[[:cntrl:][:space:]:?^~\[]|\\\\|\\*|\\.lock$|\\.lock/|@\\{|[/.]$|^@$|^$";
+extern std::regex badGitRefRegex;
+
+// A Git revision (a SHA-1 commit hash).
+const static std::string revRegexS = "[0-9a-fA-F]{40}";
+extern std::regex revRegex;
+
+// A ref or revision, or a ref followed by a revision.
+const static std::string refAndOrRevRegex = "(?:(" + revRegexS + ")|(?:(" + refRegexS + ")(?:/(" + revRegexS + "))?))";
+
+const static std::string flakeIdRegexS = "[a-zA-Z][a-zA-Z0-9_-]*";
+extern std::regex flakeIdRegex;
+
+}
diff --git a/src/libutil/url.cc b/src/libutil/url.cc
index 88c09eef9..c1bab866c 100644
--- a/src/libutil/url.cc
+++ b/src/libutil/url.cc
@@ -1,4 +1,5 @@
 #include "url.hh"
+#include "url-parts.hh"
 #include "util.hh"
 
 namespace nix {
diff --git a/src/libutil/url.hh b/src/libutil/url.hh
index 1f716ba10..6e77142e3 100644
--- a/src/libutil/url.hh
+++ b/src/libutil/url.hh
@@ -2,8 +2,6 @@
 
 #include "error.hh"
 
-#include <regex>
-
 namespace nix {
 
 struct ParsedURL
@@ -29,40 +27,4 @@ std::map<std::string, std::string> decodeQuery(const std::string & query);
 
 ParsedURL parseURL(const std::string & url);
 
-// URI stuff.
-const static std::string pctEncoded = "(?:%[0-9a-fA-F][0-9a-fA-F])";
-const static std::string schemeRegex = "(?:[a-z+.-]+)";
-const static std::string ipv6AddressRegex = "(?:\\[[0-9a-fA-F:]+\\])";
-const static std::string unreservedRegex = "(?:[a-zA-Z0-9-._~])";
-const static std::string subdelimsRegex = "(?:[!$&'\"()*+,;=])";
-const static std::string hostnameRegex = "(?:(?:" + unreservedRegex + "|" + pctEncoded + "|" + subdelimsRegex + ")*)";
-const static std::string hostRegex = "(?:" + ipv6AddressRegex + "|" + hostnameRegex + ")";
-const static std::string userRegex = "(?:(?:" + unreservedRegex + "|" + pctEncoded + "|" + subdelimsRegex + "|:)*)";
-const static std::string authorityRegex = "(?:" + userRegex + "@)?" + hostRegex + "(?::[0-9]+)?";
-const static std::string pcharRegex = "(?:" + unreservedRegex + "|" + pctEncoded + "|" + subdelimsRegex + "|[:@])";
-const static std::string queryRegex = "(?:" + pcharRegex + "|[/? \"])*";
-const static std::string segmentRegex = "(?:" + pcharRegex + "+)";
-const static std::string absPathRegex = "(?:(?:/" + segmentRegex + ")*/?)";
-const static std::string pathRegex = "(?:" + segmentRegex + "(?:/" + segmentRegex + ")*/?)";
-
-// A Git ref (i.e. branch or tag name).
-const static std::string refRegexS = "[a-zA-Z0-9][a-zA-Z0-9_.-]*"; // FIXME: check
-extern std::regex refRegex;
-
-// Instead of defining what a good Git Ref is, we define what a bad Git Ref is
-// This is because of the definition of a ref in refs.c in https://github.com/git/git
-// See tests/fetchGitRefs.sh for the full definition
-const static std::string badGitRefRegexS = "//|^[./]|/\\.|\\.\\.|[[:cntrl:][:space:]:?^~\[]|\\\\|\\*|\\.lock$|\\.lock/|@\\{|[/.]$|^@$|^$";
-extern std::regex badGitRefRegex;
-
-// A Git revision (a SHA-1 commit hash).
-const static std::string revRegexS = "[0-9a-fA-F]{40}";
-extern std::regex revRegex;
-
-// A ref or revision, or a ref followed by a revision.
-const static std::string refAndOrRevRegex = "(?:(" + revRegexS + ")|(?:(" + refRegexS + ")(?:/(" + revRegexS + "))?))";
-
-const static std::string flakeIdRegexS = "[a-zA-Z][a-zA-Z0-9_-]*";
-extern std::regex flakeIdRegex;
-
 }