skin this cat

luakiwi/.clang-format

@@ -0,0 +1,88 @@
+AccessModifierOffset: -2
+AlignAfterOpenBracket: BlockIndent    # New in v14. For earlier clang-format versions, use AlwaysBreak instead.
+AlignConsecutiveMacros: false
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignEscapedNewlines: DontAlign
+AlignOperands: false
+AlignTrailingComments: false
+AllowAllArgumentsOnNextLine: false
+AllowAllConstructorInitializersOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: Empty
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: Empty
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLambdasOnASingleLine: All
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: true
+AlwaysBreakTemplateDeclarations: Yes
+BinPackArguments: false
+BinPackParameters: false
+BreakAfterAttributes: Always
+BreakBeforeBinaryOperators: NonAssignment
+BreakBeforeBraces: Attach
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializers: AfterColon
+BreakInheritanceList: AfterColon
+BreakStringLiterals: false
+ColumnLimit: 98
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DerivePointerAlignment: false
+FixNamespaceComments: true
+IncludeBlocks: Regroup
+IncludeCategories:
+  - Regex:           '^<ext/.*\.h>'
+    Priority:        2
+    SortPriority:    0
+    CaseSensitive:   false
+  - Regex:           '^<.*\.h>'
+    Priority:        1
+    SortPriority:    0
+    CaseSensitive:   false
+  - Regex:           '^<.*'
+    Priority:        2
+    SortPriority:    0
+    CaseSensitive:   false
+  - Regex:           '.*'
+    Priority:        3
+    SortPriority:    0
+    CaseSensitive:   false
+IncludeIsMainRegex: '([-_](test|unittest))?$'
+IndentCaseLabels: true
+IndentPPDirectives: BeforeHash
+IndentWidth: 3
+IndentWrappedFunctionNames: false
+KeepEmptyLinesAtTheStartOfBlocks: false
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: Inner
+PointerAlignment: Left
+ReferenceAlignment: Left              # New in v13. int &name  ==>  int& name
+ReflowComments: false
+SeparateDefinitionBlocks: Always      # New in v14.
+SortIncludes: true
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: false
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: false
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCpp11BracedList: true
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: false
+SpaceBeforeParens: ControlStatements
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 2
+SpacesInAngles: false
+SpacesInCStyleCastParentheses: false
+SpacesInContainerLiterals: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard: Cpp11
+TabWidth: 4
+UseTab: Never

luakiwi/kiwibridge.cpp

@@ -0,0 +1,331 @@
+#include <kiwi/kiwi.h>
+
+#include <cstdlib>
+#include <cstring>
+
+namespace {
+
+using namespace kiwi;
+
+enum KiwiErrKind {
+   KiwiErrNone,
+   KiwiErrUnsatisfiableConstraint = 1,
+   KiwiErrUnknownConstraint,
+   KiwiErrDuplicateConstraint,
+   KiwiErrUnknownEditVariable,
+   KiwiErrDuplicateEditVariable,
+   KiwiErrBadRequiredStrength,
+   KiwiErrInternalSolverError,
+   KiwiErrAlloc,
+   KiwiErrNullObject,
+   KiwiErrUnknown,
+};
+
+enum KiwiRelOp { KIWI_OP_LE, KIWI_OP_GE, KIWI_OP_EQ };
+
+typedef struct KiwiVarRefType* KiwiVarRef;
+typedef struct KiwiConstraintRefType* KiwiConstraintRef;
+
+struct KiwiTerm {
+   Variable* var;
+   double coefficient;
+};
+
+struct KiwiExpression {
+   double constant;
+   int term_count;
+   Constraint* owner;
+   KiwiTerm terms[1];  // LuaJIT: struct KiwiTerm terms_[?];
+};
+
+struct KiwiErr {
+   enum KiwiErrKind kind;
+   const char* message;
+   bool must_free;
+};
+
+struct KiwiSolver {
+   unsigned error_mask;
+   Solver solver;
+};
+
+template<typename T, typename R, typename... Args>
+inline R make_cref(Args&&... args) {
+   static_assert(
+       sizeof(R) >= sizeof(T),  // NOLINT(bugprone-sizeof-expression)
+       "to_cref: R too small for T"
+   );
+   static_assert(alignof(R) >= alignof(T), "to_cref: R alignment too small for T");
+
+   R cref;
+   new (&cref) T(std::forward<Args>(args)...);
+   return cref;
+}
+
+template<typename... Args>
+inline decltype(auto) make_var_cref(Args&&... args) {
+   return make_cref<Variable, KiwiVarRef>(std::forward<Args>(args)...);
+}
+
+template<typename... Args>
+inline decltype(auto) make_constraint_cref(Args&&... args) {
+   return make_cref<Constraint, KiwiConstraintRef>(std::forward<Args>(args)...);
+}
+
+template<class T, class R>
+class SharedRef {
+ private:
+   R& cref_;
+
+ public:
+   explicit SharedRef<T, R>(R& cref) : cref_(cref) {}
+
+   static_assert(
+       sizeof(R) >= sizeof(T),  // NOLINT(bugprone-sizeof-expression)
+       "SharedRef<T,CS> CS too small for T"
+   );
+
+   R clone() const {
+      return make_cref<T, R>(cref());
+   }
+
+   void release() {
+      if (cref_) {
+         ptr()->~T();
+         cref_ = nullptr;
+      }
+   }
+
+   T* ptr() {
+      T* p;
+      void* s = &cref_;
+      std::memcpy(&p, &s, sizeof p);  // NOLINT(bugprone-sizeof-expression)
+      return p;
+   }
+
+   const T* const_ptr() const {
+      const T* p;
+      const void* s = &cref_;
+      std::memcpy(&p, &s, sizeof p);  // NOLINT(bugprone-sizeof-expression)
+      return p;
+   }
+
+   const T& cref() const {
+      return *const_ptr();
+   }
+
+   T* operator&() const {
+      return ptr();
+   }
+
+   T* operator->() {
+      return ptr();
+   }
+
+   const T* operator->() const {
+      return const_ptr();
+   }
+
+   operator const T&() const {
+      return cref();
+   }
+
+   explicit operator bool() const {
+      return cref_;
+   }
+};
+
+using ConstraintRef = SharedRef<Constraint, KiwiConstraintRef>;
+using VariableRef = SharedRef<Variable, KiwiVarRef>;
+using ConstVariableRef = const SharedRef<const Variable, const KiwiVarRef>;
+
+const KiwiErr* new_error(const KiwiErr* base, const std::exception& ex) {
+   if (!std::strcmp(ex.what(), base->message))
+      return base;
+
+   const auto msg_n = std::strlen(ex.what()) + 1;
+
+   auto* mem = static_cast<char*>(std::malloc(sizeof(KiwiErr) + msg_n));
+   if (!mem) {
+      return base;
+   }
+
+   const auto* err = new (mem) KiwiErr {base->kind, mem + sizeof(KiwiErr), true};
+   std::memcpy(const_cast<char*>(err->message), ex.what(), msg_n);
+   return err;
+}
+
+const constexpr KiwiErr kKiwiErrUnhandledCxxException {
+    KiwiErrUnknown,
+    "An unhandled C++ exception occurred."};
+
+const constexpr KiwiErr kKiwiErrNullObjectArg0 {
+    KiwiErrNullObject,
+    "null object passed as argument #0 (self)"};
+
+const constexpr KiwiErr kKiwiErrNullObjectArg1 {
+    KiwiErrNullObject,
+    "null object passed as argument #1"};
+
+template<typename F>
+inline const KiwiErr* wrap_err(F&& f) {
+   try {
+      f();
+   } catch (const UnsatisfiableConstraint& ex) {
+      static const constexpr KiwiErr err {
+          KiwiErrUnsatisfiableConstraint,
+          "The constraint cannot be satisfied."};
+      return &err;
+   } catch (const UnknownConstraint& ex) {
+      static const constexpr KiwiErr err {
+          KiwiErrUnknownConstraint,
+          "The constraint has not been added to the solver."};
+      return &err;
+
+   } catch (const DuplicateConstraint& ex) {
+      static const constexpr KiwiErr err {
+          KiwiErrDuplicateConstraint,
+          "The constraint has already been added to the solver."};
+      return &err;
+
+   } catch (const UnknownEditVariable& ex) {
+      static const constexpr KiwiErr err {
+          KiwiErrUnknownEditVariable,
+          "The edit variable has not been added to the solver."};
+      return &err;
+
+   } catch (const DuplicateEditVariable& ex) {
+      static const constexpr KiwiErr err {
+          KiwiErrDuplicateEditVariable,
+          "The edit variable has already been added to the solver."};
+      return &err;
+
+   } catch (const BadRequiredStrength& ex) {
+      static const constexpr KiwiErr err {
+          KiwiErrBadRequiredStrength,
+          "A required strength cannot be used in this context."};
+      return &err;
+
+   } catch (const InternalSolverError& ex) {
+      static const constexpr KiwiErr base {
+          KiwiErrInternalSolverError,
+          "An internal solver error occurred."};
+      return new_error(&base, ex);
+   } catch (std::bad_alloc&) {
+      static const constexpr KiwiErr err {KiwiErrAlloc, "A memory allocation failed."};
+      return &err;
+   } catch (const std::exception& ex) {
+      return new_error(&kKiwiErrUnhandledCxxException, ex);
+   } catch (...) {
+      return &kKiwiErrUnhandledCxxException;
+   }
+   return nullptr;
+}
+
+template<typename P, typename R, typename F>
+inline const KiwiErr* wrap_err(P ptr, F&& f) {
+   if (!ptr) {
+      return &kKiwiErrNullObjectArg0;
+   }
+   return wrap_err([&]() { f(ptr); });
+}
+
+template<typename P, typename R, typename F>
+inline const KiwiErr* wrap_err(P ptr, R& ref, F&& f) {
+   if (!ptr) {
+      return &kKiwiErrNullObjectArg0;
+   }
+   return wrap_err([&]() { f(ptr, ref); });
+}
+
+// inline void kiwi_var_del(KiwiVarRef var) { VariableRef(var).release(); }
+
+inline Variable* kiwi_var_retain(Variable* var) {
+   alignas(Variable) unsigned char buf[sizeof(Variable)];
+   new (buf) Variable(*var);
+   return var;
+}
+
+inline Constraint* kiwi_constraint_retain(Constraint* c) {
+   alignas(Constraint) unsigned char buf[sizeof(Constraint)];
+   new (buf) Constraint(*c);
+   return c;
+}
+
+inline void kiwi_constraint_new(
+    const KiwiExpression* lhs,
+    const KiwiExpression* rhs,
+    enum KiwiRelOp op,
+    double strength,
+    Constraint* mem
+) {
+   if (strength < 0.0) {
+      strength = kiwi::strength::required;
+   }
+
+   std::vector<Term> terms;
+   terms.reserve((lhs ? lhs->term_count : 0) + (rhs ? rhs->term_count : 0));
+
+   if (lhs) {
+      // FIXME FIXME: this should cause a copy!
+      for (auto* t = lhs->terms; t != lhs->terms + lhs->term_count; ++t) {
+         terms.emplace_back(*t->var, t->coefficient);
+      }
+   }
+   if (rhs) {
+      for (auto* t = rhs->terms; t != rhs->terms + rhs->term_count; ++t) {
+         terms.emplace_back(*t->var, -t->coefficient);
+      }
+   }
+   new (mem) Constraint(
+       Expression(std::move(terms), (lhs ? lhs->constant : 0.0) - (rhs ? rhs->constant : 0.0)),
+       static_cast<RelationalOperator>(op),
+       strength
+   );
+}
+
+int kiwi_constraint_expression(const Constraint* c, KiwiExpression* out, int out_size) {
+   const auto& expr = c->expression();
+   const auto& terms = expr.terms();
+   const int n_terms = terms.size();
+   if (!out || out_size < n_terms)
+      return n_terms;
+
+   // FIXME FIXME FIXME: dangling pointer
+   auto* p = out->terms;
+   for (const auto& t : terms) {
+      Variable* v = const_cast<Variable*>(&t.variable());
+      *p = KiwiTerm {v, t.coefficient()};
+      ++p;
+   }
+   out->term_count = p - out->terms;
+   out->constant = expr.constant();
+
+   return n_terms;
+}
+
+inline const KiwiErr* kiwi_solver_add_constraint(KiwiSolver* s, const Constraint& constraint) {
+   return wrap_err(s, constraint, [](auto* s, const auto& c) { s->solver.addConstraint(c); });
+}
+
+inline const KiwiErr* kiwi_solver_remove_constraint(KiwiSolver* s, const Constraint& constraint) {
+   return wrap_err(s, constraint, [](auto* s, const auto& c) { s->solver.removeConstraint(c); });
+}
+
+inline const KiwiErr*
+kiwi_solver_add_edit_var(KiwiSolver* s, const Variable& var, double strength) {
+   return wrap_err(s, var, [strength](auto* s, const auto& v) {
+      s->solver.addEditVariable(v, strength);
+   });
+}
+
+inline const KiwiErr* kiwi_solver_remove_edit_var(KiwiSolver* s, const Variable& var) {
+   return wrap_err(s, var, [](auto* s, const auto& v) { s->solver.removeEditVariable(v); });
+}
+
+inline const KiwiErr*
+kiwi_solver_suggest_value(KiwiSolver* s, const Variable& var, double value) {
+   return wrap_err(s, var, [value](auto* s, const auto& v) { s->solver.suggestValue(v, value); });
+}
+
+}  // namespace

luakiwi/luacompat.h

@@ -0,0 +1,147 @@
+#ifndef LKIWI_LUACOMPAT_H_
+#define LKIWI_LUACOMPAT_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif  // __cplusplus
+#include <lauxlib.h>
+#include <lua.h>
+#include <lualib.h>
+#ifdef __cplusplus
+}
+#endif  // __cplusplus
+
+#if !defined(LUA_VERSION_NUM) || LUA_VERSION_NUM == 501
+
+   #define LUA_OPADD 0
+   #define LUA_OPSUB 1
+   #define LUA_OPMUL 2
+   #define LUA_OPDIV 3
+   #define LUA_OPMOD 4
+   #define LUA_OPPOW 5
+   #define LUA_OPUNM 6
+
+static int lua_absindex(lua_State* L, int i) {
+   if (i < 0 && i > LUA_REGISTRYINDEX)
+      i += lua_gettop(L) + 1;
+   return i;
+}
+
+static lua_Number lua_tonumberx(lua_State* L, int i, int* isnum) {
+   lua_Number n = lua_tonumber(L, i);
+   if (isnum != NULL) {
+      *isnum = (n != 0 || lua_isnumber(L, i));
+   }
+   return n;
+}
+
+static lua_Integer lua_tointegerx(lua_State* L, int i, int* isnum) {
+   int ok = 0;
+   lua_Number n = lua_tonumberx(L, i, &ok);
+   if (ok) {
+      if (n == (lua_Integer)n) {
+         if (isnum)
+            *isnum = 1;
+         return (lua_Integer)n;
+      }
+   }
+   if (isnum)
+      *isnum = 0;
+   return 0;
+}
+
+static const char* luaL_tolstring(lua_State* L, int idx, size_t* len) {
+   if (!luaL_callmeta(L, idx, "__tostring")) {
+      int t = lua_type(L, idx), tt = 0;
+      char const* name = NULL;
+      switch (t) {
+         case LUA_TNIL:
+            lua_pushliteral(L, "nil");
+            break;
+         case LUA_TSTRING:
+         case LUA_TNUMBER:
+            lua_pushvalue(L, idx);
+            break;
+         case LUA_TBOOLEAN:
+            if (lua_toboolean(L, idx))
+               lua_pushliteral(L, "true");
+            else
+               lua_pushliteral(L, "false");
+            break;
+         default:
+            tt = luaL_getmetafield(L, idx, "__name");
+            name = (tt == LUA_TSTRING) ? lua_tostring(L, -1) : lua_typename(L, t);
+            lua_pushfstring(L, "%s: %p", name, lua_topointer(L, idx));
+            if (tt != LUA_TNIL)
+               lua_replace(L, -2);
+            break;
+      }
+   } else {
+      if (!lua_isstring(L, -1))
+         luaL_error(L, "'__tostring' must return a string");
+   }
+   return lua_tolstring(L, -1, len);
+}
+
+#endif /* LUA_VERSION_NUM == 501 */
+
+#if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM <= 502
+
+static void compat_reverse(lua_State* L, int a, int b) {
+   for (; a < b; ++a, --b) {
+      lua_pushvalue(L, a);
+      lua_pushvalue(L, b);
+      lua_replace(L, a);
+      lua_replace(L, b);
+   }
+}
+
+static void lua_rotate(lua_State* L, int idx, int n) {
+   int n_elems = 0;
+   idx = lua_absindex(L, idx);
+   n_elems = lua_gettop(L) - idx + 1;
+   if (n < 0)
+      n += n_elems;
+   if (n > 0 && n < n_elems) {
+      luaL_checkstack(L, 2, "not enough stack slots available");
+      n = n_elems - n;
+      compat_reverse(L, idx, idx + n - 1);
+      compat_reverse(L, idx + n, idx + n_elems - 1);
+      compat_reverse(L, idx, idx + n_elems - 1);
+   }
+}
+
+static int lua_geti(lua_State* L, int index, lua_Integer i) {
+   index = lua_absindex(L, index);
+   lua_pushinteger(L, i);
+   lua_gettable(L, index);
+   return lua_type(L, -1);
+}
+
+#endif /* LUA_VERSION_NUM <= 502 */
+
+#if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM <= 503
+static int luaL_typeerror(lua_State* L, int arg, const char* tname) {
+   const char* msg;
+   const char* typearg; /* name for the type of the actual argument */
+   if (luaL_getmetafield(L, arg, "__name") == LUA_TSTRING)
+      typearg = lua_tostring(L, -1); /* use the given type name */
+   else if (lua_type(L, arg) == LUA_TLIGHTUSERDATA)
+      typearg = "light userdata"; /* special name for messages */
+   else
+      typearg = luaL_typename(L, arg); /* standard name */
+   msg = lua_pushfstring(L, "%s expected, got %s", tname, typearg);
+   return luaL_argerror(L, arg, msg);
+}
+
+#endif /* LUA_VERSION_NUM <= 503 */
+
+#if !defined(luaL_newlibtable)
+   #define luaL_newlibtable(L, l) lua_createtable(L, 0, sizeof(l) / sizeof((l)[0]) - 1)
+#endif
+
+#if !defined(luaL_checkversion)
+   #define luaL_checkversion(L) ((void)0)
+#endif
+
+#endif  // LKIWI_LUACOMPAT_H_

luakiwi/luakiwi-int.h

@@ -0,0 +1,84 @@
+#ifndef LUAKIWI_INT_H_
+#define LUAKIWI_INT_H_
+
+#include "luacompat.h"
+
+#define ARR_COUNT(x) ((int)(sizeof(x) / sizeof((x)[0])))
+
+#if defined(__GNUC__) && !defined(LKIWI_NO_BUILTIN)
+   #define l_likely(x) (__builtin_expect(((x) != 0), 1))
+   #define l_unlikely(x) (__builtin_expect(((x) != 0), 0))
+#else
+   #define l_likely(x) (x)
+   #define l_unlikely(x) (x)
+#endif
+
+#ifndef LKIWI_NO_STALLOC
+   #if defined(_MSC_VER)
+      #include <malloc.h>
+
+static inline void* stalloc(size_t sz) {
+   void* p = _malloca(sz);
+   if (!p) {
+      luaL_error(L, "out of memory");
+   }
+   return p;
+}
+
+      #define stfree(ptr) _freea(ptr)
+   #else
+      #include <alloca.h>
+      #define stalloc alloca
+      #define stfree(ptr)
+   #endif
+#else
+   #include <stdlib.h>
+
+static inline void* stalloc(size_t sz) {
+   void* p = malloc(sz);
+   if (l_unlikely(!p)) {
+      luaL_error(L, "out of memory");
+   }
+   return p;
+}
+
+   #define stfree(ptr) free(ptr)
+#endif
+
+// Lua 5.1 compatibility for missing lua_arith.
+static void compat_arith_unm(lua_State* L) {
+#if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM == 501
+   lua_Number n = lua_tonumber(L, -1);
+   if (n != 0 || lua_isnumber(L, -1)) {
+      lua_pop(L, 1);
+      lua_pushnumber(L, -n);
+   } else {
+      if (!luaL_callmeta(L, -1, "__unm"))
+         luaL_error(L, "attempt to perform arithmetic on a %s value", luaL_typename(L, -1));
+      lua_replace(L, -2);
+   }
+#else
+   lua_arith(L, LUA_OPUNM);
+#endif
+}
+
+// This version supports placeholders.
+static void setfuncs(lua_State* L, const luaL_Reg* l, int nup) {
+   luaL_checkstack(L, nup, "too many upvalues");
+   for (; l->name != NULL; l++) { /* fill the table with given functions */
+      if (l->func == NULL) /* place holder? */
+         lua_pushboolean(L, 0);
+      else {
+         int i;
+         for (i = 0; i < nup; i++) /* copy upvalues to the top */
+            lua_pushvalue(L, -nup);
+         lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */
+      }
+      lua_setfield(L, -(nup + 2), l->name);
+   }
+   lua_pop(L, nup); /* remove upvalues */
+}
+
+#define newlib(L, l) (lua_newtable((L)), setfuncs((L), (l), 0))
+
+#endif  // LUAKIWI_INT_H_