Add support for parsing semantic and semantic-like versions

5 files changed, 443 insertions, 4 deletions

diff --git a/libbutl/semantic-version.cxx b/libbutl/semantic-version.cxx
new file mode 100644
index 0000000..2427202
--- /dev/null
+++ b/libbutl/semantic-version.cxx
@@ -0,0 +1,150 @@
+// file      : libbutl/semantic-version.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2018 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef __cpp_modules
+#include <libbutl/semantic-version.mxx>
+#endif
+
+#include <cassert>
+
+#ifndef __cpp_lib_modules
+#include <string>
+#include <cstddef>
+#include <cstdint>
+#include <ostream>
+
+#include <cstring>   // strchr()
+#include <cstdlib>   // strtoull()
+#include <utility>   // move()
+#include <stdexcept> // invalid_argument
+#endif
+
+// Other includes.
+
+#ifdef __cpp_modules
+module butl.semantic_version;
+
+// Only imports additional to interface.
+#ifdef __clang__
+#ifdef __cpp_lib_modules
+import std.core;
+import std.io;
+#endif
+import butl.optional;
+#endif
+#else
+#endif
+
+using namespace std;
+
+namespace butl
+{
+  string semantic_version::
+  string (bool ib) const
+  {
+    std::string r;
+    r  = to_string (major);
+    r += '.';
+    r += to_string (minor);
+    r += '.';
+    r += to_string (patch);
+    if (!ib) r += build;
+    return r;
+  }
+
+  uint64_t semantic_version::
+  numeric () const
+  {
+    if (const char* w = (major > 999 ? "major version greater than 999" :
+                         minor > 999 ? "minor version greater than 999" :
+                         patch > 999 ? "patch version greater than 999" :
+                         nullptr))
+      throw invalid_argument (w);
+
+    // AAABBBCCC0000
+    //   10000000000
+    //      10000000
+    //         10000
+    //
+    return (major * 10000000000) + (minor * 10000000) + (patch * 10000);
+  }
+
+  semantic_version::
+  semantic_version (uint64_t n, std::string b)
+      : build (move (b))
+  {
+    //      AAABBBCCC0000
+    if (n > 9999999990000ULL || (n % 1000) != 0)
+      throw invalid_argument ("invalid numeric representation");
+
+    //        AAABBBCCC0000
+    major = n / 10000000000 % 1000;
+    minor = n /    10000000 % 1000;
+    patch = n /       10000 % 1000;
+  }
+
+  semantic_version::
+  semantic_version (const std::string& s, size_t p, const char* bs)
+  {
+    semantic_version_result r (parse_semantic_version_impl (s, p, bs));
+
+    if (r.version)
+      *this = move (*r.version);
+    else
+      throw invalid_argument (r.failure_reason);
+  }
+
+  // From standard-version.cxx
+  //
+  bool
+  parse_uint64 (const string& s, size_t& p,
+                uint64_t& r,
+                uint64_t min = 0, uint64_t max = uint64_t (~0));
+
+  semantic_version_result
+  parse_semantic_version_impl (const string& s, size_t p, const char* bs)
+  {
+    auto bail = [] (string m)
+    {
+      return semantic_version_result {nullopt, move (m)};
+    };
+
+    semantic_version r;
+
+    if (!parse_uint64 (s, p, r.major))
+      return bail ("invalid major version");
+
+    if (s[p] != '.')
+      return bail ("'.' expected after major version");
+
+    if (!parse_uint64 (s, ++p, r.minor))
+      return bail ("invalid minor version");
+
+    if (s[p] == '.')
+    {
+      // Treat it as build if failed to parse as patch (e.g., 1.2.alpha).
+      //
+      if (!parse_uint64 (s, ++p, r.patch))
+      {
+        //if (require_patch)
+        //  return bail ("invalid patch version");
+
+        --p;
+        // Fall through.
+      }
+    }
+    //else if (require_patch)
+    //  return bail ("'.' expected after minor version");
+
+    if (char c = s[p])
+    {
+      if (bs == nullptr || (*bs != '\0' && strchr (bs, c) == nullptr))
+        return bail ("junk after version");
+
+      r.build.assign (s, p, string::npos);
+    }
+
+    return semantic_version_result {move (r), string ()};
+  }
+}
diff --git a/libbutl/semantic-version.ixx b/libbutl/semantic-version.ixx
new file mode 100644
index 0000000..cd88663
--- /dev/null
+++ b/libbutl/semantic-version.ixx
@@ -0,0 +1,78 @@
+// file      : libbutl/semantic-version.ixx -*- C++ -*-
+// copyright : Copyright (c) 2014-2018 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+namespace butl
+{
+  inline semantic_version::
+  semantic_version (std::uint64_t mj,
+                    std::uint64_t mi,
+                    std::uint64_t p,
+                    std::string   b)
+      : major (mj),
+        minor (mi),
+        patch (p),
+        build (std::move (b))
+  {
+  }
+
+  inline semantic_version::
+  semantic_version (const std::string& s, bool ab)
+      : semantic_version (s, ab ? "-+" : nullptr)
+  {
+  }
+
+  inline semantic_version::
+  semantic_version (const std::string& s, const char* bs)
+      : semantic_version (s, 0, bs)
+  {
+  }
+
+  inline semantic_version::
+  semantic_version (const std::string& s, std::size_t p, bool ab)
+      : semantic_version (s, p, ab ? "-+" : nullptr)
+  {
+  }
+
+  inline int semantic_version::
+  compare (const semantic_version& v, bool ib) const
+  {
+    return (major != v.major ? (major < v.major ? -1 : 1) :
+            minor != v.minor ? (minor < v.minor ? -1 : 1) :
+            patch != v.patch ? (patch < v.patch ? -1 : 1) :
+            ib ? 0 : build.compare (v.build));
+  }
+
+  struct semantic_version_result
+  {
+    optional<semantic_version> version;
+    std::string failure_reason;
+  };
+
+  LIBBUTL_SYMEXPORT semantic_version_result
+  parse_semantic_version_impl (const std::string&, std::size_t, const char*);
+
+  inline optional<semantic_version>
+  parse_semantic_version (const std::string& s, bool ab)
+  {
+    return parse_semantic_version (s, ab ? "-+" : nullptr);
+  }
+
+  inline optional<semantic_version>
+  parse_semantic_version (const std::string& s, const char* bs)
+  {
+    return parse_semantic_version_impl (s, 0, bs).version;
+  }
+
+  inline optional<semantic_version>
+  parse_semantic_version (const std::string& s, std::size_t p, bool ab)
+  {
+    return parse_semantic_version (s, p, ab ? "-+" : nullptr);
+  }
+
+  inline optional<semantic_version>
+  parse_semantic_version (const std::string& s, std::size_t p, const char* bs)
+  {
+    return parse_semantic_version_impl (s, p, bs).version;
+  }
+}
diff --git a/libbutl/semantic-version.mxx b/libbutl/semantic-version.mxx
new file mode 100644
index 0000000..d64eb82
--- /dev/null
+++ b/libbutl/semantic-version.mxx
@@ -0,0 +1,187 @@
+// file      : libbutl/semantic-version.mxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2018 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef __cpp_modules
+#pragma once
+#endif
+
+// C includes.
+
+#ifndef __cpp_lib_modules
+#include <string>
+#include <cstddef> // size_t
+#include <cstdint> // uint*_t
+#include <utility> // move()
+#include <ostream>
+#endif
+
+// Other includes.
+
+#ifdef __cpp_modules
+export module butl.semantic_version;
+#ifdef __cpp_lib_modules
+import std.core;
+import std.io;
+#endif
+import butl.optional;
+#else
+#include <libbutl/optional.mxx>
+#endif
+
+#include <libbutl/export.hxx>
+
+// FreeBSD defines these macros in its <sys/types.h>.
+//
+#ifdef major
+#  undef major
+#endif
+
+#ifdef minor
+#  undef minor
+#endif
+
+LIBBUTL_MODEXPORT namespace butl
+{
+  // Semantic or semantic-like version.
+  //
+  // <major>.<minor>[.<patch>][<build>]
+  //
+  // If the patch component is absent, then it defaults to 0.
+  //
+  // @@ Currently there is no way to enforce the three-component version.
+  //    Supporting this will require changing allow_build to a bit-wise
+  //    flag. See parse_semantic_version_impl() for some sketched code.
+  //    We may also want to pass these flags to string() to not print
+  //    0 patch.
+  //
+  // By default, a version containing the <build> component is considered
+  // valid only if separated from <patch> with '-' (semver pre-release) or '+'
+  // (semver build metadata). However, as discussed below, the list of valid
+  // separators can be customized to recognize other semver-like formats.
+  //
+  // Note also that the format of semver pre-release and build metadata are
+  // not validated.
+  //
+  struct LIBBUTL_SYMEXPORT semantic_version
+  {
+    std::uint64_t major = 0;
+    std::uint64_t minor = 0;
+    std::uint64_t patch = 0;
+    std::string   build;
+
+    // Construct the semantic version from various representations. Throw
+    // std::invalid_argument if the format is not recognizable or components
+    // are invalid.
+    //
+    semantic_version () = default;
+
+    semantic_version (std::uint64_t major,
+                      std::uint64_t minor,
+                      std::uint64_t patch,
+                      std::string   build = "");
+
+    // The build_separators argument can be NULL (no build component allowed),
+    // empty (any build component allowed), or a string of characters to allow
+    // as separators. When allow_build is true build_separators defaults to
+    // "-+".
+    //
+    explicit
+    semantic_version (const std::string&, bool allow_build = true);
+
+    semantic_version (const std::string&, const char* build_separators);
+
+    // As above but parse from the specified position until the end of the
+    // string.
+    //
+    semantic_version (const std::string&, std::size_t pos, bool = true);
+
+    semantic_version (const std::string&, std::size_t pos, const char*);
+
+    std::string
+    string (bool ignore_build = false) const;
+
+    // Numeric representation in the AAABBBCCC0000 form, where:
+    //
+    // AAA - major version number
+    // BBB - minor version number
+    // CCC - patch version number
+    //
+    // See standard version for details.
+    //
+    explicit
+    semantic_version (std::uint64_t numeric, std::string build = "");
+
+    // If any of the major/minor/patch components is greater than 999, then
+    // throw std::invalid_argument. The build component is ignored.
+    //
+    std::uint64_t
+    numeric () const;
+
+    // Unless instructed to ignore, the build components are compared
+    // lexicographically.
+    //
+    int
+    compare (const semantic_version&, bool ignore_build = false) const;
+  };
+
+  // Try to parse a string as a semantic version returning nullopt if invalid.
+  //
+  optional<semantic_version>
+  parse_semantic_version (const std::string&, bool allow_build = true);
+
+  optional<semantic_version>
+  parse_semantic_version (const std::string&, const char* build_separators);
+
+  optional<semantic_version>
+  parse_semantic_version (const std::string&, std::size_t pos, bool = true);
+
+  optional<semantic_version>
+  parse_semantic_version (const std::string&, std::size_t pos, const char*);
+
+  // NOTE: comparison operators take the build component into account.
+  //
+  inline bool
+  operator< (const semantic_version& x, const semantic_version& y) noexcept
+  {
+    return x.compare (y) < 0;
+  }
+
+  inline bool
+  operator> (const semantic_version& x, const semantic_version& y) noexcept
+  {
+    return x.compare (y) > 0;
+  }
+
+  inline bool
+  operator== (const semantic_version& x, const semantic_version& y) noexcept
+  {
+    return x.compare (y) == 0;
+  }
+
+  inline bool
+  operator<= (const semantic_version& x, const semantic_version& y) noexcept
+  {
+    return x.compare (y) <= 0;
+  }
+
+  inline bool
+  operator>= (const semantic_version& x, const semantic_version& y) noexcept
+  {
+    return x.compare (y) >= 0;
+  }
+
+  inline bool
+  operator!= (const semantic_version& x, const semantic_version& y) noexcept
+  {
+    return !(x == y);
+  }
+
+  inline std::ostream&
+  operator<< (std::ostream& o, const semantic_version& x)
+  {
+    return o << x.string ();
+  }
+}
+
+#include <libbutl/semantic-version.ixx>
diff --git a/libbutl/standard-version.cxx b/libbutl/standard-version.cxx
index e4180d1..fc2d528 100644
--- a/libbutl/standard-version.cxx
+++ b/libbutl/standard-version.cxx
@@ -42,12 +42,17 @@ using namespace std;
 
 namespace butl
 {
-  // Utility functions
+  // Parse uint64_t from the specified string starting at the specified
+  // position and check the min/max constraints. If successful, save the
+  // result, update the position to point to the next character, and return
+  // true. Otherwise return false (result and position are unchanged).
   //
-  static bool
+  // Note: also used for semantic_version parsing.
+  //
+  bool
   parse_uint64 (const string& s, size_t& p,
                 uint64_t& r,
-                uint64_t min, uint64_t max)
+                uint64_t min = 0, uint64_t max = uint64_t (~0))
   {
     if (s[p] == '-' || s[p] == '+') // strtoull() allows these.
       return false;
@@ -59,8 +64,8 @@ namespace butl
     if (errno == ERANGE || b == e || v < min || v > max)
       return false;
 
+    r = v;
     p = e - s.c_str ();
-    r = static_cast<uint64_t> (v);
     return true;
   }
 
diff --git a/libbutl/standard-version.mxx b/libbutl/standard-version.mxx
index 5f019c4..7b1f232 100644
--- a/libbutl/standard-version.mxx
+++ b/libbutl/standard-version.mxx
@@ -48,6 +48,25 @@ LIBBUTL_MODEXPORT namespace butl
   // [+<epoch>-]<maj>.<min>.<patch>-
   // 0[+<revision>]
   //
+  // The numeric version format is AAABBBCCCDDDE where:
+  //
+  // AAA - major version number
+  // BBB - minor version number
+  // CCC - patch version number
+  // DDD - alpha / beta (DDD + 500) version number
+  // E   - final (0) / snapshot (1)
+  //
+  // When DDDE is not 0, 1 is subtracted from AAABBBCCC. For example:
+  //
+  // Version      AAABBBCCCDDDE
+  //
+  // 0.1.0        0000010000000
+  // 0.1.2        0000010010000
+  // 1.2.3        0010020030000
+  // 2.2.0-a.1    0020019990010
+  // 3.0.0-b.2    0029999995020
+  // 2.2.0-a.1.z  0020019990011
+  //
   struct LIBBUTL_SYMEXPORT standard_version
   {
     // Invariants: