add sok_solve_cbs_t and refactor code to use it

2 files changed, 27 insertions, 11 deletions

diff --git a/src/core/sok-solve.c b/src/core/sok-solve.c
index 34a8320..45d227c 100644
--- a/src/core/sok-solve.c
+++ b/src/core/sok-solve.c
@@ -7,7 +7,8 @@ static bool
 sok_solve_step(
   sok_ctx_t * const ctx,
   sok_cache_t * const cache,
-  void (*on_error)(const char * const)
+  const sok_solve_cbs_t * const cbs,
+  void * const user_data
 ) {
   // check for success
   if (sok_ctx_is_done(ctx)) {
@@ -22,15 +23,19 @@ sok_solve_step(
 
   // add to cache
   if (!sok_cache_add(cache, ctx)) {
-    if (on_error) {
+    if (cbs && cbs->on_error) {
       // log error
-      on_error("sok_cache_add() failed");
+      cbs->on_error("sok_cache_add() failed", user_data);
     }
 
     // return failure
     return false;
   }
 
+  if (cbs && cbs->on_step && !cbs->on_step(ctx, user_data)) {
+    // return failure
+    return false;
+  }
 /* 
  *   // make sure level is solvable
  *   if (sok_ctx_is_lost(ctx)) {
@@ -45,16 +50,16 @@ sok_solve_step(
     }
 
     // recurse, check for success
-    if (sok_solve_step(ctx, cache, on_error)) {
+    if (sok_solve_step(ctx, cache, cbs, user_data)) {
       // return success
       return true;
     }
 
     // undo move
     if (!sok_ctx_undo(ctx)) {
-      if (on_error) {
+      if (cbs && cbs->on_error) {
         // log error
-        on_error("sok_ctx_undo() failed");
+        cbs->on_error("sok_ctx_undo() failed", user_data);
       }
 
       // return failure
@@ -66,20 +71,25 @@ sok_solve_step(
   return false;
 }
 
-bool 
+bool
 sok_solve(
   sok_ctx_t * const ctx,
-  void (*on_error)(const char * const)
+  const sok_solve_cbs_t * const cbs,
+  void *user_data
 ) {
   // init cache
   sok_cache_t cache;
   if (!sok_cache_init(&cache, SOK_CACHE_DEFAULT_CAPACITY)) {
-    on_error("sok_cache_init() failed");
+    if (cbs && cbs->on_error) {
+      cbs->on_error("sok_cache_init() failed", user_data);
+    }
+
+    // return failure
     return false;
   }
 
   // solve
-  const bool r = sok_solve_step(ctx, &cache, on_error);
+  const bool r = sok_solve_step(ctx, &cache, cbs, user_data);
 
   // finalize cache
   sok_cache_fini(&cache);
diff --git a/src/core/sok.h b/src/core/sok.h
index 1503b5f..92fb4e7 100644
--- a/src/core/sok.h
+++ b/src/core/sok.h
@@ -245,9 +245,15 @@ _Bool sok_cache_add(sok_cache_t * const, const sok_ctx_t * const);
 /* solve */
 /*********/
 
+typedef struct {
+  _Bool (*on_step)(const sok_ctx_t *, void *);
+  void (*on_error)(const char * const, void *);
+} sok_solve_cbs_t;
+
 _Bool sok_solve(
   sok_ctx_t * const,
-  void (*on_error)(const char * const)
+  const sok_solve_cbs_t * const,
+  void * const
 );
 
 #ifdef __cplusplus