3 files changed, 30 insertions, 3 deletions
diff --git a/TODO b/TODO
index 1fea73e..9b7a05e 100644
--- a/TODO
+++ b/TODO
@@ -1,14 +1,14 @@
 maybe make the repl use the readline library.
-create lisp code for addition.
 use secure functions.
 make quest a thing.
 remove macros?
 
-split, join.
-make unit testing.
 instead of returning "#<Lambda ..." it should return the expression.
 remove lambda_type and macro_type.
+create lisp code for addition.
+make unit testing.
 
+split, join. (done)
 make numbers be symbols. (done)
 make number symbols neutral. (done)
 fix a security bug of setting a primitive. (done)
diff --git a/liblali.c b/liblali.c
index ac552c2..9afec71 100644
--- a/liblali.c
+++ b/liblali.c
@@ -1075,6 +1075,30 @@ Object *primitiveJoin(Object **args, GC_PARAM) {
     return newSymbol(symbolResult, GC_ROOTS);
 }
 
+Object *primitiveSplit(Object **args, GC_PARAM) {
+  Object *symbol = (*args)->car;
+
+  if (symbol == nil || (symbol->type != TYPE_SYMBOL &&
+                        symbol->type != TYPE_STRING &&
+                        symbol->type != TYPE_NUMBER))
+    exceptionWithObject(symbol, "is not a symbol, not a number, not a string");
+
+  GC_TRACE(gcRes, nil);
+  GC_TRACE(gcElement, nil);
+  char string[2] = {'\0'};
+  size_t size = strlen(symbol->string);
+  for (unsigned long i = 0; i < size; i++) {
+    string[0] = symbol->string[i];
+    if (symbol->type == TYPE_STRING)
+      *gcElement = newString(string, GC_ROOTS);
+    else
+      *gcElement = newSymbol(string, GC_ROOTS);
+
+    *gcRes = newCons(gcElement, gcRes, GC_ROOTS);
+  }
+  return reverseList(*gcRes);
+}
+
 typedef struct Primitive {
   char *name;
   int nMinArgs, nMaxArgs;
@@ -1118,6 +1142,7 @@ Primitive primitives[] = {
   { ">",       1, -1, primitiveGreater      },
   /* { ">=",      1, -1, primitiveGreaterEqual } */
   { "join",    1,  1, primitiveJoin         },
+  { "split",   1,  1, primitiveSplit        },
 };
 
 // Special forms handled by evalExpr. Must be in the same order as above.
diff --git a/liblali.h b/liblali.h
index a9b17d0..d1d7c24 100644
--- a/liblali.h
+++ b/liblali.h
@@ -333,6 +333,8 @@ Object *primitiveGreater(Object **args, GC_PARAM);
 
 Object *primitiveJoin(Object **args, GC_PARAM);
 
+Object *primitiveSplit(Object **args, GC_PARAM);
+
 // EVALUATION /////////////////////////////////////////////////////////////////
 
 /* Scheme-style tail recursive evaluation. evalProg, evalProgs, evalCond, and