From 0592d58e5366eac92bc99ef9bdb4368e07c0ddf9 Mon Sep 17 00:00:00 2001
From: Karen Arutyunov <karen@codesynthesis.com>
Date: Wed, 4 Aug 2021 20:31:30 +0300
Subject: Add extract_package_name() and extract_package_version()

---
 libbpkg/manifest.cxx | 37 +++++++++++++++++++++++++++++++++++++
 libbpkg/manifest.hxx | 30 ++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)

diff --git a/libbpkg/manifest.cxx b/libbpkg/manifest.cxx
index 210aa3b..d4c3f9d 100644
--- a/libbpkg/manifest.cxx
+++ b/libbpkg/manifest.cxx
@@ -4573,4 +4573,41 @@ namespace bpkg
 
     s.next ("", ""); // End of manifest.
   }
+
+  // extract_package_*()
+  //
+  package_name
+  extract_package_name (const char* s, bool allow_version)
+  {
+    if (!allow_version)
+      return package_name (s);
+
+    // Calculate the package name length as a length of the prefix that
+    // doesn't contain spaces, slashes and the version constraint starting
+    // characters. Note that none of them are valid package name characters.
+    //
+    size_t n (strcspn (s, " /=<>([~^"));
+    return package_name (string (s, n));
+  }
+
+  version
+  extract_package_version (const char* s, bool fold_zero_revision)
+  {
+    using traits = string::traits_type;
+
+    if (const char* p = traits::find (s, traits::length (s), '/'))
+    {
+      version r (p + 1, fold_zero_revision);
+
+      if (r.release && r.release->empty ())
+        throw invalid_argument ("earliest version");
+
+      if (r.compare (stub_version, true /* ignore_revision */) == 0)
+        throw invalid_argument ("stub version");
+
+      return r;
+    }
+
+    return version ();
+  }
 }
diff --git a/libbpkg/manifest.hxx b/libbpkg/manifest.hxx
index b666716..bdb7a9b 100644
--- a/libbpkg/manifest.hxx
+++ b/libbpkg/manifest.hxx
@@ -1568,6 +1568,36 @@ namespace bpkg
                         butl::manifest_name_value start,
                         bool ignore_unknown);
   };
+
+  // Extract the package name component from <name>[/<version>] or
+  // <name><version-constraint>. Throw invalid_argument on parsing error.
+  //
+  // Note: the version and version constraint are not verified.
+  //
+  LIBBPKG_EXPORT package_name
+  extract_package_name (const char*, bool allow_version = true);
+
+  inline package_name
+  extract_package_name (const std::string& s, bool allow_version = true)
+  {
+    return extract_package_name (s.c_str (), allow_version);
+  }
+
+  // Extract the package version component from <name>[/<version>]. Return
+  // empty version if none is specified. Throw invalid_argument on parsing
+  // error and for the earliest and stub versions.
+  //
+  // Note: the package name is not verified.
+  //
+  LIBBPKG_EXPORT version
+  extract_package_version (const char*, bool fold_zero_revision = true);
+
+  inline version
+  extract_package_version (const std::string& s,
+                           bool fold_zero_revision = true)
+  {
+    return extract_package_version (s.c_str (), fold_zero_revision);
+  }
 }
 
 #endif // LIBBPKG_MANIFEST_HXX
-- 
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