From c85de58a2047c4858825d03977e490db6168fbe3 Mon Sep 17 00:00:00 2001
From: Peter Mikkelsen <peter@pmikkelsen.com>
Date: Fri, 23 Jul 2021 00:50:18 +0000
Subject: Simplify parsing a bit, and make sure the prolog loader calls
 read_term with the correct module to pick up the correct operators

---
 parser.c | 92 +++++++---------------------------------------------------------
 1 file changed, 9 insertions(+), 83 deletions(-)

(limited to 'parser.c')

diff --git a/parser.c b/parser.c
index 04b2b68..b00382d 100644
--- a/parser.c
+++ b/parser.c
@@ -52,67 +52,32 @@ Term *compound(void);
 Term *parseoperators(Term *);
 void match(int);
 void syntaxerror_parser(char *);
-Term *prologtext(int);
-void handlemoduledirective(Term *);
-void handleopdirective(Term *);
+Term *parseterm(void);
 
 Term *
-parse(int fd, Biobuf *bio, int querymode)
+parse(Biobuf *bio, Module *mod)
 {
-	if(bio == nil){
-		fd = dup(fd, -1);
-		parsein = Bfdopen(fd, OREAD);
-		if(parsein == nil){
-			print("Could not open file\n");
-			return nil;
-		}
-	}else
-		parsein = bio;
-
+	parsein = bio;
+	currentmod = mod;
 	nexttoken();
-	currentmod = getmodule(L"user");
 
-	Term *result = prologtext(querymode);
-	if(querymode && result){
+	Term *result = parseterm();
+	if(result){
 		result = copyterm(result, &clausenr);
 		clausenr++;
 	}
-	if(!bio)
-		Bterm(parsein);
-
 	return result;
 }
 
 Term *
-prologtext(int querymode)
+parseterm(void)
 {
 	if(lookahead.tag == EofTok)
 		return nil;
 
 	Term *t = fullterm(AtomTok, L".", nil);
-	if(lookahead.tag == AtomTok && runestrcmp(lookahead.text, L".") == 0){
-		if(!querymode)
-			match(AtomTok);
-	}else
-		syntaxerror_parser("prologtext");
-
-	if(querymode)
-		return t;
-
-	if(t->tag == CompoundTerm && runestrcmp(t->text, L":-") == 0 && t->arity == 1){
-		Term *body = t->children;
-		if(runestrcmp(body->text, L"op") == 0 && body->arity == 3)
-			handleopdirective(body->children);
-
-		t = prologtext(querymode);
-	}else if(t->tag == CompoundTerm && runestrcmp(t->text, L":-") == 0 && t->arity == 2){
-		t->next = prologtext(querymode);
-	}else if(t->tag == AtomTerm || t->tag == CompoundTerm){
-		t->next = prologtext(querymode);
-	}else{
-		print("Expected directive or clause as toplevel\n");
-		syntaxerror_parser("prologtext");
-	}
+	if(lookahead.tag != AtomTok || runestrcmp(lookahead.text, L".") != 0)
+		syntaxerror_parser("parseterm");
 
 	return t;
 }
@@ -572,42 +537,3 @@ syntaxerror_parser(char *where)
 	print("Syntax error: Unexpected %d (%S) token in %s\n", lookahead.tag, lookahead.text, where);
 	exits("syntax error");
 }
-
-void
-handleopdirective(Term *args)
-{
-	Term *levelt = args;
-	Term *typet = levelt->next;
-	Term *opt = typet->next;
-	if(levelt->tag == IntegerTerm 
-	    && levelt->ival >= 0 
-	    && levelt->ival <= PrecedenceLevels
-	    && typet->tag == AtomTerm
-	    && opt->tag == AtomTerm){
-		int level = levelt->ival;
-		Rune *spelling = opt->text;
-		int type = 0;
-		if(runestrcmp(typet->text, L"xf") == 0)
-			type = Xf;
-		else if(runestrcmp(typet->text, L"yf") == 0)
-			type = Yf;
-		else if(runestrcmp(typet->text, L"xfx") == 0)
-			type = Xfx;
-		else if(runestrcmp(typet->text, L"xfy") == 0)
-			type = Xfy;
-		else if(runestrcmp(typet->text, L"yfx") == 0)
-			type = Yfx;
-		else if(runestrcmp(typet->text, L"fy") == 0)
-			type = Fy;
-		else if(runestrcmp(typet->text, L"fx") == 0)
-			type = Fx;
-		if(type != 0){
-			addoperator(level, type, spelling, currentmod);
-			return;
-		}
-	}
-	print("Malformed op directive with level=%S, type=%S, op=%S\n",
-		prettyprint(levelt, 0, 0, 0, currentmod),
-		prettyprint(typet, 0, 0, 0, currentmod),
-		prettyprint(opt, 0, 0, 0, currentmod));
-}
\ No newline at end of file
-- 
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