From f02d615052e325616d7042096cea6e5247a980dc Mon Sep 17 00:00:00 2001
From: Rainer Gerhards <rgerhards@adiscon.com>
Date: Wed, 20 Feb 2008 09:54:58 +0000
Subject: - basic implementation of expression parser parsing done - improved
 ABNF a bit

---
 expr.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 86 insertions(+), 9 deletions(-)

(limited to 'expr.c')

diff --git a/expr.c b/expr.c
index b059dac7..bb72cb89 100644
--- a/expr.c
+++ b/expr.c
@@ -50,12 +50,14 @@ DEFobjStaticHelpers
  * rgerhards, 2008-02-19
  */
 
+/* forward definiton - thanks to recursive ABNF, we can not avoid at least one ;) */
+static rsRetVal expr(expr_t *pThis, ctok_t *ctok);
+
 #if 0
 static rsRetVal
 template(expr_t *pThis, ctok_t *ctok)
 {
 	DEFiRet;
-RUNLOG_STR("");
 
 	ISOBJ_TYPE_assert(pThis, expr);
 	ISOBJ_TYPE_assert(ctok, ctok);
@@ -73,7 +75,6 @@ terminal(expr_t *pThis, ctok_t *ctok)
 {
 	DEFiRet;
 	ctok_token_t *pToken;
-RUNLOG_STR("terminal");
 
 	ISOBJ_TYPE_assert(pThis, expr);
 	ISOBJ_TYPE_assert(ctok, ctok);
@@ -82,8 +83,33 @@ RUNLOG_STR("terminal");
 
 	switch(pToken->tok) {
 		case ctok_SIMPSTR:
+			dbgoprint((obj_t*) pThis, "simpstr\n");
+			break;
+		case ctok_NUMBER:
+			dbgoprint((obj_t*) pThis, "number\n");
+			break;
+		case ctok_FUNCTION:
+			dbgoprint((obj_t*) pThis, "function\n");
+			break;
+		case ctok_MSGVAR:
+			dbgoprint((obj_t*) pThis, "MSGVAR\n");
+			break;
+		case ctok_SYSVAR:
+			dbgoprint((obj_t*) pThis, "SYSVAR\n");
+			break;
+		case ctok_LPAREN:
+			dbgoprint((obj_t*) pThis, "expr\n");
+			CHKiRet(ctok_tokenDestruct(&pToken)); /* "eat" processed token */
+			CHKiRet(expr(pThis, ctok));
+			CHKiRet(ctokGetToken(ctok, &pToken)); /* get next one */
+			if(pToken->tok != ctok_RPAREN)
+				ABORT_FINALIZE(RS_RET_SYNTAX_ERROR);
+			CHKiRet(ctok_tokenDestruct(&pToken)); /* "eat" processed token */
+			dbgoprint((obj_t*) pThis, "end expr, rparen eaten\n");
+			/* fill structure */
 			break;
 		default:
+			dbgoprint((obj_t*) pThis, "invalid token %d\n", pToken->tok);
 			ABORT_FINALIZE(RS_RET_SYNTAX_ERROR);
 			break;
 	}
@@ -96,11 +122,21 @@ static rsRetVal
 factor(expr_t *pThis, ctok_t *ctok)
 {
 	DEFiRet;
-RUNLOG_STR("factor");
+	ctok_token_t *pToken;
 
 	ISOBJ_TYPE_assert(pThis, expr);
 	ISOBJ_TYPE_assert(ctok, ctok);
 
+	CHKiRet(ctokGetToken(ctok, &pToken));
+	if(pToken->tok == ctok_NOT) {
+		/* TODO: fill structure */
+		dbgprintf("not\n");
+		CHKiRet(ctok_tokenDestruct(&pToken)); /* no longer needed */
+		CHKiRet(ctokGetToken(ctok, &pToken)); /* get next one */
+	} else {
+		/* we could not process the token, so push it back */
+		CHKiRet(ctokUngetToken(ctok, pToken));
+	}
 	CHKiRet(terminal(pThis, ctok));
 
 finalize_it:
@@ -112,7 +148,6 @@ static rsRetVal
 term(expr_t *pThis, ctok_t *ctok)
 {
 	DEFiRet;
-RUNLOG_STR("term");
 
 	ISOBJ_TYPE_assert(pThis, expr);
 	ISOBJ_TYPE_assert(ctok, ctok);
@@ -128,7 +163,6 @@ val(expr_t *pThis, ctok_t *ctok)
 {
 	DEFiRet;
 	ctok_token_t *pToken;
-RUNLOG_STR("val");
 
 	ISOBJ_TYPE_assert(pThis, expr);
 	ISOBJ_TYPE_assert(ctok, ctok);
@@ -155,13 +189,26 @@ static rsRetVal
 e_cmp(expr_t *pThis, ctok_t *ctok)
 {
 	DEFiRet;
-RUNLOG_STR("e_cmp");
+	ctok_token_t *pToken;
 
 	ISOBJ_TYPE_assert(pThis, expr);
 	ISOBJ_TYPE_assert(ctok, ctok);
 
 	CHKiRet(val(pThis, ctok));
 
+ 	/* 0*1(cmp_op val) part */
+	CHKiRet(ctokGetToken(ctok, &pToken));
+	if(ctok_tokenIsCmpOp(pToken)) {
+		dbgoprint((obj_t*) pThis, "cmp\n");
+		/* fill structure */
+		CHKiRet(ctok_tokenDestruct(&pToken)); /* no longer needed */
+		CHKiRet(val(pThis, ctok));
+	} else {
+		/* we could not process the token, so push it back */
+		CHKiRet(ctokUngetToken(ctok, pToken));
+	}
+
+
 finalize_it:
 	RETiRet;
 }
@@ -171,13 +218,28 @@ static rsRetVal
 e_and(expr_t *pThis, ctok_t *ctok)
 {
 	DEFiRet;
-RUNLOG_STR("e_and");
+	ctok_token_t *pToken;
 
 	ISOBJ_TYPE_assert(pThis, expr);
 	ISOBJ_TYPE_assert(ctok, ctok);
 
 	CHKiRet(e_cmp(pThis, ctok));
 
+ 	/* *("and" e_cmp) part */
+	CHKiRet(ctokGetToken(ctok, &pToken));
+	while(pToken->tok == ctok_AND) {
+		dbgoprint((obj_t*) pThis, "and\n");
+		/* fill structure */
+		CHKiRet(ctok_tokenDestruct(&pToken)); /* no longer needed */
+		CHKiRet(e_cmp(pThis, ctok));
+		CHKiRet(ctokGetToken(ctok, &pToken));
+	}
+
+	/* unget the token that made us exit the loop - it's obviously not one
+	 * we can process.
+	 */
+	CHKiRet(ctokUngetToken(ctok, pToken)); 
+
 finalize_it:
 	RETiRet;
 }
@@ -187,13 +249,28 @@ static rsRetVal
 expr(expr_t *pThis, ctok_t *ctok)
 {
 	DEFiRet;
-RUNLOG_STR("expr");
+	ctok_token_t *pToken;
 
 	ISOBJ_TYPE_assert(pThis, expr);
 	ISOBJ_TYPE_assert(ctok, ctok);
 
 	CHKiRet(e_and(pThis, ctok));
 
+ 	/* *("or" e_and) part */
+	CHKiRet(ctokGetToken(ctok, &pToken));
+	while(pToken->tok == ctok_OR) {
+		/* fill structure */
+		dbgoprint((obj_t*) pThis, "found OR\n");
+		CHKiRet(ctok_tokenDestruct(&pToken)); /* no longer needed */
+		CHKiRet(e_and(pThis, ctok));
+		CHKiRet(ctokGetToken(ctok, &pToken));
+	}
+
+	/* unget the token that made us exit the loop - it's obviously not one
+	 * we can process.
+	 */
+	CHKiRet(ctokUngetToken(ctok, pToken)); 
+
 finalize_it:
 	RETiRet;
 }
@@ -281,8 +358,8 @@ exprParse(expr_t *pThis, ctok_t *ctok)
 	ISOBJ_TYPE_assert(ctok, ctok);
 
 	CHKiRet(expr(pThis, ctok));
+	dbgoprint((obj_t*) pThis, "successfully parsed/created expression\n");
 
-RUNLOG_STR("expr parser being called");
 finalize_it:
 	RETiRet;
 }
-- 
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