More flexible error handling, convenience methods

Allow getting solver errors returned rather than raising error.
The API allows setting a mask of which error kinds raise vs return.

Also add some convenience methods:
- `add_to` and `remove_from` constraint methods to solver.
- add and remove multiple constraints and edit/suggest variables at once

ckiwi/ckiwi.cpp

@@ -343,95 +343,84 @@ int kiwi_constraint_expression(KiwiConstraintRef constraint, KiwiExpression* out
    return n_terms;
 }
 
-KiwiSolver* kiwi_solver_new() {
+struct KiwiSolver {
-   return reinterpret_cast<KiwiSolver*>(new Solver());
+   unsigned error_mask;
+   Solver solver;
+};
+
+KiwiSolver* kiwi_solver_new(unsigned error_mask) {
+   return new KiwiSolver {error_mask};
 }
 
-void kiwi_solver_del(KiwiSolver* sp) {
+void kiwi_solver_del(KiwiSolver* s) {
-   auto* solver = reinterpret_cast<Solver*>(sp);
+   if (s)
-   if (solver)
+      delete s;
-      delete solver;
 }
 
 const KiwiErr* kiwi_solver_add_constraint(KiwiSolver* s, KiwiConstraintRef constraint) {
-   return wrap_err(
+   return wrap_err(s, ConstraintRef(constraint), [](auto* s, const auto c) {
-       reinterpret_cast<Solver*>(s),
+      s->solver.addConstraint(c);
-       ConstraintRef(constraint),
+   });
-       [](auto solver, const auto c) { solver->addConstraint(c); }
-   );
 }
 
 const KiwiErr* kiwi_solver_remove_constraint(KiwiSolver* s, KiwiConstraintRef constraint) {
-   return wrap_err(
+   return wrap_err(s, ConstraintRef(constraint), [](auto* s, const auto c) {
-       reinterpret_cast<Solver*>(s),
+      s->solver.removeConstraint(c);
-       ConstraintRef(constraint),
+   });
-       [](auto solver, const auto c) { solver->removeConstraint(c); }
-   );
 }
 
 bool kiwi_solver_has_constraint(const KiwiSolver* s, KiwiConstraintRef constraint) {
-   const auto* solver = reinterpret_cast<const Solver*>(s);
    ConstraintRef c(constraint);
-   if (!solver || !c)
+   if (!s || !c)
       return 0;
-   return solver->hasConstraint(c);
+   return s->solver.hasConstraint(c);
 }
 
 const KiwiErr* kiwi_solver_add_edit_var(KiwiSolver* s, KiwiVarRef var, double strength) {
-   return wrap_err(
+   return wrap_err(s, VariableRef(var), [strength](auto* s, const auto v) {
-       reinterpret_cast<Solver*>(s),
+      s->solver.addEditVariable(v, strength);
-       VariableRef(var),
+   });
-       [strength](auto solver, const auto v) { solver->addEditVariable(v, strength); }
-   );
 }
 
 const KiwiErr* kiwi_solver_remove_edit_var(KiwiSolver* s, KiwiVarRef var) {
-   return wrap_err(reinterpret_cast<Solver*>(s), VariableRef(var), [](auto solver, const auto v) {
+   return wrap_err(s, VariableRef(var), [](auto* s, const auto v) {
-      solver->removeEditVariable(v);
+      s->solver.removeEditVariable(v);
    });
 }
 
 bool kiwi_solver_has_edit_var(const KiwiSolver* s, KiwiVarRef var) {
-   const auto* solver = reinterpret_cast<const Solver*>(s);
    VariableRef v(var);
-   if (!solver || !v)
+   if (!s || !v)
       return 0;
-   return solver->hasEditVariable(v);
+   return s->solver.hasEditVariable(v);
 }
 
 const KiwiErr* kiwi_solver_suggest_value(KiwiSolver* s, KiwiVarRef var, double value) {
-   return wrap_err(
+   return wrap_err(s, VariableRef(var), [value](auto* s, const auto v) {
-       reinterpret_cast<Solver*>(s),
+      s->solver.suggestValue(v, value);
-       VariableRef(var),
+   });
-
-       [value](auto solver, const auto v) { solver->suggestValue(v, value); }
-   );
 }
 
 void kiwi_solver_update_vars(KiwiSolver* s) {
-   auto* solver = reinterpret_cast<Solver*>(s);
+   if (s)
-   if (solver)
+      s->solver.updateVariables();
-      solver->updateVariables();
 }
 
 void kiwi_solver_reset(KiwiSolver* s) {
-   auto* solver = reinterpret_cast<Solver*>(s);
+   if (s)
-   if (solver)
+      s->solver.reset();
-      solver->reset();
 }
 
 void kiwi_solver_dump(const KiwiSolver* s) {
-   auto* solver = reinterpret_cast<const Solver*>(s);
+   if (s)
-   if (solver)
+      s->solver.dump();
-      solver->dump();
 }
 
 char* kiwi_solver_dumps(const KiwiSolver* s) {
-   auto* solver = reinterpret_cast<const Solver*>(s);
+   if (!s)
-   if (!solver)
       return nullptr;
 
-   const auto str = solver->dumps();  // upstream library defect
+   const auto str = s->solver.dumps();  // upstream library defect
    const auto buf_size = str.size() + 1;
    auto* buf = static_cast<char*>(std::malloc(buf_size));
    if (!buf)

ckiwi/ckiwi.h

@@ -46,8 +46,8 @@ typedef struct KiwiErr {
    bool must_free;
 } KiwiErr;
 
-typedef struct KiwiSolver KiwiSolver;
+typedef struct KiwiSolver
-
+    KiwiSolver;  // LuaJIT: typedef struct { unsigned error_mask; } KiwiSolver;
 KiwiVarRef kiwi_var_new(const char* name);
 void kiwi_var_del(KiwiVarRef var);
 KiwiVarRef kiwi_var_clone(KiwiVarRef var);
@@ -74,8 +74,8 @@ enum KiwiRelOp kiwi_constraint_op(KiwiConstraintRef constraint);
 bool kiwi_constraint_violated(KiwiConstraintRef constraint);
 int kiwi_constraint_expression(KiwiConstraintRef constraint, KiwiExpression* out, int out_size);
 
-KiwiSolver* kiwi_solver_new();
+KiwiSolver* kiwi_solver_new(unsigned error_mask);
-void kiwi_solver_del(KiwiSolver* sp);
+void kiwi_solver_del(KiwiSolver* s);
 
 const KiwiErr* kiwi_solver_add_constraint(KiwiSolver* sp, KiwiConstraintRef constraint);
 const KiwiErr* kiwi_solver_remove_constraint(KiwiSolver* sp, KiwiConstraintRef constraint);

kiwi.lua

@@ -48,7 +48,7 @@ typedef struct KiwiErr {
    bool must_free;
 } KiwiErr;
 
-typedef struct KiwiSolver KiwiSolver;
+typedef struct KiwiSolver { unsigned error_mask; } KiwiSolver;
 
 KiwiVarRef kiwi_var_new(const char* name);
 void kiwi_var_del(KiwiVarRef var);
@@ -76,8 +76,8 @@ enum KiwiRelOp kiwi_constraint_op(KiwiConstraintRef constraint);
 bool kiwi_constraint_violated(KiwiConstraintRef constraint);
 int kiwi_constraint_expression(KiwiConstraintRef constraint, KiwiExpression* out, int out_size);
 
-KiwiSolver* kiwi_solver_new();
+KiwiSolver* kiwi_solver_new(unsigned error_mask);
-void kiwi_solver_del(KiwiSolver* sp);
+void kiwi_solver_del(KiwiSolver* s);
 
 const KiwiErr* kiwi_solver_add_constraint(KiwiSolver* sp, KiwiConstraintRef constraint);
 const KiwiErr* kiwi_solver_remove_constraint(KiwiSolver* sp, KiwiConstraintRef constraint);
@@ -720,6 +720,27 @@ do
       return ffi_gc(expr, ckiwi.kiwi_expression_del_vars) --[[@as kiwi.Expression]]
    end
 
+   --- Add the constraint to the solver.
+   --- Raises:
+   --- KiwiErrDuplicateConstraint: The given constraint has already been added to the solver.
+   --- KiwiErrUnsatisfiableConstraint: The given constraint is required and cannot be satisfied.
+   ---@param solver kiwi.Solver
+   ---@return kiwi.Constraint
+   function Constraint_cls:add_to(solver)
+      solver:add_constraints(self)
+      return self
+   end
+
+   --- Remove the constraint from the solver.
+   --- Raises:
+   --- KiwiErrUnknownConstraint: The given constraint has not been added to the solver.
+   ---@param solver kiwi.Solver
+   ---@return kiwi.Constraint
+   function Constraint_cls:remove_from(solver)
+      solver:remove_constraints(self)
+      return self
+   end
+
    local Constraint_mt = {
       __index = Constraint_cls,
    }
@@ -818,8 +839,33 @@ do
 end
 
 do
+   local bit = require("bit")
+   local band, bor, lshift = bit.band, bit.bor, bit.lshift
    local C = ffi.C
 
+   --- Produce a custom error raise mask
+   --- Error kinds specified in the mask will not cause a lua
+   --- error to be raised.
+   ---@param kinds (kiwi.ErrKind|number)[]
+   ---@param invert boolean?
+   ---@return integer
+   function kiwi.error_mask(kinds, invert)
+      local mask = 0
+      for _, k in ipairs(kinds) do
+         mask = bor(mask, lshift(1, kiwi.ErrKind(k)))
+      end
+      return invert and bit.bnot(mask) or mask
+   end
+
+   kiwi.ERROR_MASK_ALL = 0xFFFF
+   --- an error mask that raises errors only for fatal conditions
+   kiwi.ERROR_MASK_NON_FATAL = bit.bnot(kiwi.error_mask({
+      "KiwiErrInternalSolverError",
+      "KiwiErrAlloc",
+      "KiwiErrNullObject",
+      "KiwiErrUnknown",
+   }))
+
    ---@class kiwi.KiwiErr: ffi.cdata*
    ---@field package kind kiwi.ErrKind
    ---@field package message ffi.cdata*
@@ -828,8 +874,10 @@ do
    local KiwiErr = ffi.typeof("struct KiwiErr") --[[@as kiwi.KiwiErr]]
 
    local Error_mt = {
+      ---@param self kiwi.Error
+      ---@return string
       __tostring = function(self)
-         return strformat("%s: (%s, %s)", self.message, self.solver, self.item)
+         return strformat("%s: (%s, %s)", self.message, tostring(self.solver), tostring(self.item))
       end,
    }
 
@@ -851,9 +899,11 @@ do
       }, Error_mt)
    end
 
-   ---@param f fun(solver: kiwi.Solver, item: any, ...): kiwi.KiwiErr?
+   ---@generic T
+   ---@param f fun(solver: kiwi.Solver, item: T, ...): kiwi.KiwiErr?
    ---@param solver kiwi.Solver
-   ---@param item any
+   ---@param item T
+   ---@return T, kiwi.Error?
    local function try_solver(f, solver, item, ...)
       local err = f(solver, item, ...)
       if err ~= nil then
@@ -862,12 +912,17 @@ do
          if err.must_free then
             C.free(err)
          end
-         error(new_error(kind, message, solver, item))
+         local errdata = new_error(kind, message, solver, item)
+         return item,
+            band(solver.error_mask, lshift(1, kind --[[@as integer]])) == 0 and error(errdata)
+               or errdata
       end
+      return item
    end
 
    ---@class kiwi.Solver: ffi.cdata*
-   ---@overload fun(): kiwi.Solver
+   ---@field error_mask integer
+   ---@overload fun(error_mask: integer?): kiwi.Solver
    local Solver_cls = {
       --- Test whether a constraint is in the solver.
       ---@type fun(self: kiwi.Solver, constraint: kiwi.Constraint): boolean
@@ -896,54 +951,133 @@ do
       dump = ckiwi.kiwi_solver_dump,
    }
 
-   --- Adds a constraint to the solver.
+   ---@generic T
-   --- Raises
+   ---@param solver kiwi.Solver
-   --- KiwiErrDuplicateConstraint: The given constraint has already been added to the solver.
+   ---@param items T|T[]
-   --- KiwiErrUnsatisfiableConstraint: The given constraint is required and cannot be satisfied.
+   ---@param f fun(solver: kiwi.Solver, item: T, ...): kiwi.KiwiErr?
+   ---@return T|T[], kiwi.Error?
+   local function add_remove_items(solver, items, f, ...)
+      for _, item in ipairs(items) do
+         local _, err = try_solver(f, solver, item, ...)
+         if err ~= nil then
+            return items, err
+         end
+      end
+      return items
+   end
+
+   --- Add a constraint to the solver.
+   --- Errors:
+   --- KiwiErrDuplicateConstraint
+   --- KiwiErrUnsatisfiableConstraint
    ---@param constraint kiwi.Constraint
+   ---@return kiwi.Constraint constraint, kiwi.Error?
    function Solver_cls:add_constraint(constraint)
-      try_solver(ckiwi.kiwi_solver_add_constraint, self, constraint)
+      return try_solver(ckiwi.kiwi_solver_add_constraint, self, constraint)
    end
 
-   --- Removes a constraint from the solver.
+   --- Add constraints to the solver.
-   --- Raises
+   --- Errors:
-   --- KiwiErrUnknownConstraint: The given constraint has not been added to the solver.
+   --- KiwiErrDuplicateConstraint
+   --- KiwiErrUnsatisfiableConstraint
+   ---@param constraints kiwi.Constraint[]
+   ---@return kiwi.Constraint[] constraints, kiwi.Error?
+   function Solver_cls:add_constraints(constraints)
+      return add_remove_items(self, constraints, ckiwi.kiwi_solver_add_constraint)
+   end
+
+   --- Remove a constraint from the solver.
+   --- Errors:
+   --- KiwiErrUnknownConstraint
    ---@param constraint kiwi.Constraint
+   ---@return kiwi.Constraint constraint, kiwi.Error?
    function Solver_cls:remove_constraint(constraint)
-      try_solver(ckiwi.kiwi_solver_remove_constraint, self, constraint)
+      return try_solver(ckiwi.kiwi_solver_remove_constraint, self, constraint)
    end
 
-   --- Adds an edit variable to the solver.
+   --- Remove constraints from the solver.
+   --- Errors:
+   --- KiwiErrUnknownConstraint
+   ---@param constraints kiwi.Constraint[]
+   ---@return kiwi.Constraint[] constraints, kiwi.Error?
+   function Solver_cls:remove_constraints(constraints)
+      return add_remove_items(self, constraints, ckiwi.kiwi_solver_remove_constraint)
+   end
+
+   --- Add an edit variables to the solver.
    ---
    --- This method should be called before the `suggestValue` method is
    --- used to supply a suggested value for the given edit variable.
-   --- Raises
+   --- Errors:
-   --- KiwiErrDuplicateEditVariable: The given edit variable has already been added to the solver.
+   --- KiwiErrDuplicateEditVariable
    --- KiwiErrBadRequiredStrength: The given strength is >= required.
    ---@param var kiwi.Var the variable to add as an edit variable
    ---@param strength number the strength of the edit variable (must be less than `Strength.REQUIRED`)
+   ---@return kiwi.Var var, kiwi.Error?
    function Solver_cls:add_edit_var(var, strength)
-      try_solver(ckiwi.kiwi_solver_add_edit_var, self, var, strength)
+      return try_solver(ckiwi.kiwi_solver_add_edit_var, self, var, strength)
+   end
+
+   --- Add edit variables to the solver.
+   ---
+   --- This method should be called before the `suggestValue` method is
+   --- used to supply a suggested value for the given edit variable.
+   --- Errors:
+   --- KiwiErrDuplicateEditVariable
+   --- KiwiErrBadRequiredStrength: The given strength is >= required.
+   ---@param vars kiwi.Var[] the variables to add as an edit variable
+   ---@param strength number the strength of the edit variables (must be less than `Strength.REQUIRED`)
+   ---@return kiwi.Var[] vars, kiwi.Error?
+   function Solver_cls:add_edit_vars(vars, strength)
+      return add_remove_items(self, vars, ckiwi.kiwi_solver_add_edit_var, strength)
    end
 
    --- Remove an edit variable from the solver.
-   --- Raises
+   --- Raises:
-   --- KiwiErrUnknownEditVariable: The given edit variable has not been added to the solver
+   --- KiwiErrUnknownEditVariable
    ---@param var kiwi.Var the edit variable to remove
+   ---@return kiwi.Var var, kiwi.Error?
    function Solver_cls:remove_edit_var(var)
-      try_solver(ckiwi.kiwi_solver_remove_edit_var, self, var)
+      return try_solver(ckiwi.kiwi_solver_remove_edit_var, self, var)
+   end
+
+   --- Removes edit variables from the solver.
+   --- Raises:
+   --- KiwiErrUnknownEditVariable
+   ---@param vars kiwi.Var[] the edit variables to remove
+   ---@return kiwi.Var[] vars, kiwi.Error?
+   function Solver_cls:remove_edit_vars(vars)
+      return add_remove_items(self, vars, ckiwi.kiwi_solver_remove_edit_var)
    end
 
    --- Suggest a value for the given edit variable.
    --- This method should be used after an edit variable has been added to the solver in order
    --- to suggest the value for that variable. After all suggestions have been made,
    --- the `update_vars` methods can be used to update the values of the external solver variables.
-   --- Raises
+   --- Raises:
-   --- KiwiErrUnknownEditVariable: The given edit variable has not been added to the solver.
+   --- KiwiErrUnknownEditVariable
    ---@param var kiwi.Var the edit variable to suggest a value for
    ---@param value number the suggested value
+   ---@return kiwi.Var var, kiwi.Error?
    function Solver_cls:suggest_value(var, value)
-      try_solver(ckiwi.kiwi_solver_suggest_value, self, var, value)
+      return try_solver(ckiwi.kiwi_solver_suggest_value, self, var, value)
+   end
+
+   --- Suggest values for the given edit variables.
+   --- Convenience wrapper of `suggest_value` that takes tables of `kiwi.Var` and number pairs.
+   --- Raises:
+   --- KiwiErrUnknownEditVariable: The given edit variable has not been added to the solver.
+   ---@param vars kiwi.Var[] edit variables to suggest
+   ---@param values number[] suggested values
+   ---@return kiwi.Var[] vars, number[] values, kiwi.Error?
+   function Solver_cls:suggest_values(vars, values)
+      for i, var in ipairs(vars) do
+         local _, err = try_solver(ckiwi.kiwi_solver_suggest_value, self, var, values[i])
+         if err ~= nil then
+            return vars, values, err
+         end
+      end
+      return vars, values
    end
 
    --- Dump a representation of the solver to a string.
@@ -956,12 +1090,15 @@ do
       return s
    end
 
-   kiwi.Solver = ffi.metatype("struct KiwiSolver", {
+   local Solver_mt = {
       __index = Solver_cls,
-      __new = function(_)
+   }
-         return ffi_gc(ckiwi.kiwi_solver_new(), ckiwi.kiwi_solver_del)
+
-      end,
+   function Solver_mt:__new(error_mask)
-   }) --[[@as kiwi.Solver]]
+      return ffi_gc(ckiwi.kiwi_solver_new(error_mask or 0), ckiwi.kiwi_solver_del)
+   end
+
+   kiwi.Solver = ffi.metatype("struct KiwiSolver", Solver_mt) --[[@as kiwi.Solver]]
 end
 
 return kiwi