Add a basic repl

1 files changed, 14 insertions, 10 deletions

diff --git a/parser.c b/parser.c
index 63da254..18573b7 100644
--- a/parser.c
+++ b/parser.c
@@ -76,10 +76,10 @@ Term *compound(void);
 Term *parseoperators(Term *);
 void match(int);
 void syntaxerror(char *);
-Term *prologtext(void);
+Term *prologtext(int);
 
 Term *
-parse(int fd)
+parse(int fd, int querymode)
 {
 	parsein = Bfdopen(fd, OREAD);
 	if(parsein == nil){
@@ -90,21 +90,25 @@ parse(int fd)
 	initoperators();
 	nexttoken();
 
-	return prologtext();
+	return prologtext(querymode);
 }
 
 Term *
-prologtext(void)
+prologtext(int querymode)
 {
 	if(lookahead.tag == EofTok)
 		return nil;
 
 	Term *t = fullterm(AtomTok, L".", nil);
-	if(lookahead.tag == AtomTok && runestrcmp(lookahead.text, L".") == 0)
-		match(AtomTok);
-	else
+	if(lookahead.tag == AtomTok && runestrcmp(lookahead.text, L".") == 0){
+		if(!querymode)
+			match(AtomTok);
+	}else
 		syntaxerror("prologtext");
 
+	if(querymode)
+		return t;
+	
 	if(t->tag == CompoundTerm && runestrcmp(t->text, L":-") == 0 && t->arity == 1){
 		Term *body = t->children;
 		print("Got directive: %S\n", prettyprint(body));
@@ -113,11 +117,11 @@ prologtext(void)
 			initgoals = body->children;
 			initgoals->next = tmp;
 		}
-		t = prologtext();
+		t = prologtext(querymode);
 	}else if(t->tag == CompoundTerm && runestrcmp(t->text, L":-") == 0 && t->arity == 2){
-		t->next = prologtext();
+		t->next = prologtext(querymode);
 	}else if(t->tag == AtomTerm || t->tag == CompoundTerm){
-		t->next = prologtext();
+		t->next = prologtext(querymode);
 	}else{
 		print("Expected directive or clause as toplevel\n");
 		syntaxerror("prologtext");