Fix cyclic printing (just the printing aspect of this issue, not the …

…residual), re issue #350
trealla-prolog · Sep 26, 2023 · 9440059 · 9440059
1 parent 50d93b4
commit 9440059
Showing 1 changed file with 23 additions and 0 deletions.
diff --git a/src/print.c b/src/print.c
@@ -1068,6 +1068,7 @@ static bool print_term_to_buf_(query *q, cell *c, pl_idx c_ctx, int running, int
 
 	if (is_postfix(c)) {
 		cell *lhs = c + 1;
+		cell *save_lhs = lhs;
 		pl_idx lhs_ctx = c_ctx;
 
 		slot *e = NULL;
@@ -1089,6 +1090,12 @@ static bool print_term_to_buf_(query *q, cell *c, pl_idx c_ctx, int running, int
 		if ((c->val_off == g_plus_s) && search_op(q->st.m, C_STR(q, lhs), NULL, true) && lhs->arity) space = true;
 		if (isalpha(*src)) space = true;
 
+		if ((lhs == save_c) && (lhs_ctx == save_c_ctx)) {
+			SB_sprintf(q->sb, "%s", !is_ref(save_lhs) ? C_STR(q, save_lhs) : "_");
+			q->last_thing = WAS_OTHER;
+			return true;
+		}
+
 		if ((q->last_thing != WAS_SPACE) && space) {
 			SB_sprintf(q->sb, "%s", " ");
 			q->last_thing = WAS_SPACE;
@@ -1110,6 +1117,7 @@ static bool print_term_to_buf_(query *q, cell *c, pl_idx c_ctx, int running, int
 		}
 
 		cell *rhs = c + 1;
+		cell *save_rhs = rhs;
 		pl_idx rhs_ctx = c_ctx;
 		slot *e = NULL;
 		uint32_t save_vgen = 0;
@@ -1150,6 +1158,12 @@ static bool print_term_to_buf_(query *q, cell *c, pl_idx c_ctx, int running, int
 		SB_strcatn(q->sb, src, srclen);
 		if (quote) { SB_sprintf(q->sb, "%s", quote?"' ":""); }
 
+		if ((rhs == save_c) && (rhs_ctx == save_c_ctx)) {
+			SB_sprintf(q->sb, "%s", !is_ref(save_rhs) ? C_STR(q, save_rhs) : "_");
+			q->last_thing = WAS_OTHER;
+			return true;
+		}
+
 		if (space || parens) {
 			SB_sprintf(q->sb, "%s", " ");
 			q->last_thing = WAS_SPACE;
@@ -1162,6 +1176,7 @@ static bool print_term_to_buf_(query *q, cell *c, pl_idx c_ctx, int running, int
 			return true;
 		}
 
+		q->last_thing = WAS_OTHER;
 		if (parens) { SB_sprintf(q->sb, "%s", "("); q->last_thing = WAS_OTHER; }
 		q->parens = parens;
 		print_term_to_buf_(q, rhs, rhs_ctx, running, 0, 0, depth+1);
@@ -1173,8 +1188,10 @@ static bool print_term_to_buf_(query *q, cell *c, pl_idx c_ctx, int running, int
 	// Infix..
 
 	cell *lhs = c + 1;
+	cell *save_lhs = lhs;
 	pl_idx lhs_ctx = c_ctx;
 	cell *rhs = lhs + lhs->nbr_cells;
+	cell *save_rhs = rhs;
 	pl_idx rhs_ctx = c_ctx;
 	slot *e = NULL;
 	uint32_t save_vgen = 0;
@@ -1207,6 +1224,9 @@ static bool print_term_to_buf_(query *q, cell *c, pl_idx c_ctx, int running, int
 		if (q->last_thing != WAS_SPACE) SB_sprintf(q->sb, "%s", " ");
 		SB_sprintf(q->sb, "%s", "...");
 		q->last_thing = WAS_SYMBOL;
+	} else if ((lhs == save_c) && (lhs_ctx == save_c_ctx)) {
+		SB_sprintf(q->sb, "%s", !is_ref(save_lhs) ? C_STR(q, save_lhs) : "_");
+		q->last_thing = WAS_OTHER;
 	} else {
 		if (lhs_parens) { SB_sprintf(q->sb, "%s", "("); }
 		q->parens = lhs_parens;
@@ -1306,6 +1326,9 @@ static bool print_term_to_buf_(query *q, cell *c, pl_idx c_ctx, int running, int
 		if (q->last_thing != WAS_SPACE) SB_sprintf(q->sb, "%s", " ");
 		SB_sprintf(q->sb, "%s", "...");
 		q->last_thing = WAS_SYMBOL;
+	} else if ((rhs == save_c) && (rhs_ctx == save_c_ctx)) {
+		SB_sprintf(q->sb, "%s", !is_ref(save_rhs) ? C_STR(q, save_rhs) : "_");
+		q->last_thing = WAS_OTHER;
 	} else {
 		if (rhs_parens) { SB_sprintf(q->sb, "%s", "("); q->last_thing = WAS_OTHER; }
 		q->parens = rhs_parens || space;