4 files changed, 50 insertions, 3 deletions

diff --git a/shell/shell.c b/shell/shell.c
index 24ae243..42b3ccd 100644
--- a/shell/shell.c
+++ b/shell/shell.c
@@ -67,6 +67,7 @@ static int64_t datasize_exec(args_t *);
 static int64_t gendata_exec(args_t *);
 static int64_t solve_exec(args_t *);
 static int64_t solve_scramble_exec(args_t *);
+static int64_t countmoves_exec(args_t *);
 static int64_t help_exec(args_t *);
 
 static int parse_args(int, char **, args_t *);
@@ -202,13 +203,20 @@ struct {
                 "solve_scramble",
                 "solve_scramble " FLAG_SOLVER " SOLVER"
                 "[" FLAG_MINMOVES " n] [" FLAG_MAXMOVES " N] "
-                FLAG_CUBE " CUBE",
+                FLAG_MOVES " MOVES",
                 "Solve the given SCRAMBLE using SOLVER, "
                 "using at least n and at most N moves. "
                 INFO_MOVESFORMAT,
                 solve_scramble_exec
         ),
         COMMAND(
+                "countmoves",
+                "countmoves " FLAG_MOVES " MOVES",
+                "Count the given MOVES in HTM. "
+                INFO_MOVESFORMAT,
+                countmoves_exec
+        ),
+        COMMAND(
                 "help",
                 "help [" FLAG_COMMAND " COMMAND]",
                 "If no COMMAND is specified, prints some generic information "
@@ -488,6 +496,19 @@ solve_scramble_exec(args_t *args)
 }
 
 static int64_t
+countmoves_exec(args_t *args)
+{
+        long long count;
+
+        count = nissy_countmoves(args->str_moves);
+
+        if (count >= 0)
+                printf("%lld\n", count);
+
+        return count >= 0 ? 0 : count;
+}
+
+static int64_t
 help_exec(args_t *args)
 {
         int i;
diff --git a/src/core/moves.h b/src/core/moves.h
index d07bc19..e3a9bc1 100644
--- a/src/core/moves.h
+++ b/src/core/moves.h
@@ -223,8 +223,9 @@ readmoves(const char *buf, int max, uint8_t *ret)
         uint8_t m;
         int c;
 
-        FOREACH_READMOVE(buf, m, c, max, -1,
-                ret[c] = m;
+        FOREACH_READMOVE(buf, m, c, max, NISSY_ERROR_INVALID_MOVES,
+                if (ret != NULL)
+                        ret[c] = m;
         )
 
         return c;
diff --git a/src/nissy.c b/src/nissy.c
index fe2747b..986f27f 100644
--- a/src/nissy.c
+++ b/src/nissy.c
@@ -1,4 +1,5 @@
 #include <inttypes.h>
+#include <limits.h>
 #include <pthread.h>
 #include <stdatomic.h>
 #include <stdarg.h>
@@ -521,6 +522,17 @@ nissy_solve(
 }
 
 long long
+nissy_countmoves(
+        const char *moves
+)
+{
+        if (moves == NULL)
+                return NISSY_ERROR_NULL_POINTER;
+
+        return readmoves(moves, INT_MAX, NULL);
+}
+
+long long
 nissy_setlogger(
         void (*log)(const char *, ...)
 )
diff --git a/src/nissy.h b/src/nissy.h
index 8f4f363..7a39927 100644
--- a/src/nissy.h
+++ b/src/nissy.h
@@ -281,6 +281,19 @@ long long nissy_solve(
 );
 
 /*
+Parameters:
+   moves  - The moves to be counted.
+
+Return values:
+   NISSY_ERROR_INVALID_MOVES - The given moves are invalid.
+   NISSY_ERROR_NULL_POINTER  - The 'moves' argument is NULL.
+   Any value >= 0            - The number of moves.
+*/
+long long nissy_countmoves(
+        const char *moves
+);
+
+/*
 Set a global logger function used by this library.
 
 Parameters: