2 files changed, 69 insertions, 24 deletions

diff --git a/src/doer.c b/src/doer.c
index 19de0d8..2968882 100644
--- a/src/doer.c
+++ b/src/doer.c
@@ -74,7 +74,8 @@ char* doer_eval_str(doer_t* doer) {
 
    switch (doer->tree->type) {
       case TREE_TYPE_CALL:
-         doer->tree = doer_find_target_from_call(doer->targets, doer->tree);
+         // doer->tree = doer_find_target_from_call(doer->targets, doer->tree);
+         doer->tree = doer_do_call(doer);
          return doer_eval_str(doer);
       case TREE_TYPE_DEF:
          doer->tree = doer->tree->data.def.val;
@@ -87,38 +88,68 @@ char* doer_eval_str(doer_t* doer) {
    }
 }
 
-void blin_die(doer_t* doer) {
+tree_t* blin_die(doer_t* doer) {
    exit(1);
+   return NULL;   // Doesn't really matter what happens here.
 }
 
-void blin_print(doer_t* doer) {
+tree_t* blin_print(doer_t* doer) {
    doer->tree = doer->tree->data.call.arg->data.carg.val;
+   char* strval = doer_eval_str(doer);
 
    printf(
       "%s",
-      doer_eval_str(doer)
+      strval
    );
+
+   tree_t* lstr = tree_init(TREE_TYPE_LSTR, doer->tree->parent);
+   lstr->data.lstr.val = strval;
+   lstr->data.lstr.len = strlen(strval);
+
+   return lstr;
 }
 
-void blin_printl(doer_t* doer) {
+tree_t* blin_printl(doer_t* doer) {
    doer->tree = doer->tree->data.call.arg->data.carg.val;
+   char* strval = doer_eval_str(doer);
 
    printf(
       "%s\n",
-      doer_eval_str(doer)
+      strval
    );
+
+   tree_t* lstr = tree_init(TREE_TYPE_LSTR, doer->tree->parent);
+   lstr->data.lstr.val = strval;
+   lstr->data.lstr.len = strlen(strval);
+
+   return doer->tree;
 }
 
-void blin_str_cat(doer_t* doer) {
+tree_t* blin_str_cat(doer_t* doer) {
    tree_t* oldt = doer->tree;
    doer->tree = doer->tree->data.call.arg->data.carg.val;
    char* str1 = doer_eval_str(doer);
    doer->tree = oldt->data.call.arg->data.carg.nxt->data.carg.val;
    char* str2 = doer_eval_str(doer);
 
-   tree_destroy(doer->tree);
+   char* val = emalloc(
+      sizeof(str1) +
+      sizeof(str2) -
+      sizeof(char)
+   );
+
+   strcpy(val, str1);
+   strcat(val, str2);
+
+   free(str1);
+   free(str2);
 
-//    doer->tree = tree_init(TREE_TYPE_LSTR);
+   doer->tree = tree_init(TREE_TYPE_LSTR, oldt->parent);
+
+   doer->tree->data.lstr.val = val;
+   doer->tree->data.lstr.len = strlen(val);
+
+   return doer->tree; 
 }
 
 void doer_do_block(doer_t* doer) {
@@ -146,27 +177,38 @@ void doer_do_expr(doer_t* doer) {
 }
 
 void doer_do_def(doer_t* doer) {
+   tree_t* tag2 = doer->tree->data.def.tag->data.tag.nxt;
    target_t* target = target_init(
-      doer->tree->      // HACK: Grab the 2nd tag's value (w/o checking if
-                        // it's actually there…).
-         data.def.tag->
-         data.tag.nxt->
-         data.tag.val,
+      tag2->data.tag.val,     // HACK: Grab the 2nd tag's value, without
+                                    // checking if it's actually there…
       doer->tree
    );
 
    doer_add_target(doer, target);
 }
 
-void doer_do_call(doer_t* doer) {
+tree_t* doer_do_call(doer_t* doer) {
+   tree_t* blin = doer_do_call_blin(doer);
+   if (!blin) return doer_find_target_from_call(doer->targets, doer->tree);
+   else return blin;
+}
+
+tree_t* doer_do_call_blin(doer_t* doer) {
    // Search through built-in functions first.
    for (int i = 0; i < sizeof(blinfs) / sizeof(blinf_t); i++) {
       if (!strcmp(blinfs[i].name, doer->tree->data.call.target)) {
-         (blinfs[i].fp)(doer);
-         return;
+         return (blinfs[i].fp)(doer);
       }
    }
 
    // Search through targets next.
    LOG_DBGF("got %s", doer->ltarget->tree->data.def.tag->data.tag.nxt->data.tag.val);
+
+   return NULL;
 }
+
+// TODO: doer_do_call will check first doer_do_call_blin and then
+// doer_do_call_def for user-defined functions. Will return a tree, which will
+// replace the call in the tree.
+//
+// Maybe the parent should be set by the looping function?
diff --git a/src/include/doer.h b/src/include/doer.h
index 2bdad56..b1c8e64 100644
--- a/src/include/doer.h
+++ b/src/include/doer.h
@@ -40,7 +40,7 @@ void doer_destroy(doer_t* doer);
 
 /* Built-in function. */
 typedef struct BLINF {
-   void (*fp)(doer_t*);    // The callback function in C.
+   tree_t* (*fp)(doer_t*);    // The callback function in C.
    tree_type_t returnt;    // The return type of the function.
    tree_type_t* argts;     // Array of the arguments' types.
    char name[24];
@@ -56,26 +56,29 @@ char* doer_eval_str(doer_t* doer);
 // `die`: dies. Does not accept any arguments, returns int (if a tree falls in
 // the forest, but it burns down before anyone can hear it, did it ever make a
 // sound at all?) TODO: Make this actually clean up afterwards.
-void blin_die(doer_t* doer);
+tree_t* blin_die(doer_t* doer);
 // `print`: print a string.
-void blin_print(doer_t* doer);
+tree_t* blin_print(doer_t* doer);
 static tree_type_t blin_print_args[] = { TREE_TYPE_LSTR };
 // `printl`: print a string, and add a newline.
-void blin_printl(doer_t* doer);
+tree_t* blin_printl(doer_t* doer);
 static tree_type_t blin_printl_args[] = { TREE_TYPE_LSTR };
 // `str_cat`: concatenate strings.
-void blin_str_cat(doer_t* doer);
+// Returns a tree pointer to a lstr.
+tree_t* blin_str_cat(doer_t* doer);
 static tree_type_t blin_str_cat_args[] = { TREE_TYPE_LSTR, TREE_TYPE_LSTR };
 
+tree_t* doer_do_call(doer_t* doer);
+tree_t* doer_do_call_blin(doer_t* doer);
+tree_t* doer_do_call_def(doer_t* doer);
+tree_t* doer_do_carg(doer_t* doer);
 void doer_do_block(doer_t* tree);
 void doer_do_expr(doer_t* tree);
 void doer_do_lint(doer_t* tree);
 void doer_do_lstr(doer_t* tree);
 void doer_do_tag(doer_t* tree);
 void doer_do_darg(doer_t* tree);
-void doer_do_carg(doer_t* tree);
 void doer_do_def(doer_t* tree);
-void doer_do_call(doer_t* tree);
 
 static blinf_t blinfs[] = {
    { blin_die, TREE_TYPE_LINT, NULL, "die" },