gistfile1.diff

--- mongodb.js.orig	2010-05-04 18:59:13.000000000 +0400
+++ mongodb.js	2010-05-04 19:23:16.000000000 +0400
@@ -110,19 +110,23 @@
 					} else if (term.name == "select") {
 						options.fields = term.parameters;
 					} else if (term.name == "slice") {
-						directives.start = term.parameters[0];
-						directives.end = term.parameters[1];
+						// DVV: .start/.end MUST be numbers, or .start + a-number will result in string concat
+						// DVV: better to get rid of slice() at all, as it _may_ introduce inconsistency with range set via Range: header. As deanlandolt stated, .slice() is to mimic JS intrinsic Array.slice() and should be chainable. IOW, it doesn't fit to control server-side conditions
+						directives.start = +term.parameters[0];
+						directives.end = +term.parameters[1] + 1; // DVV: slice high bound is exclusive
 					}
 				}
 			// TODO: add support for alternate comparators, sorting, etc.
 			});
-			if(typeof directives.start === "number" || typeof directives.end === "number"){
+			// DVV: typeof NaN === 'number'
+			if(directives.start >= 0 || directives.end >= 0){
 				var totalCountPromise = callAsync(collection.count, [search]);	
 			}
 			if(directives.start){
 				options.skip = directives.start;
 			}
-			if(directives.end){
+			// DVV: .end == 0 is perfectly valid
+			if(directives.end >= 0){
 				options.limit = directives.end - (directives.start || 0) + 1;
 			}
 			return callAsync(collection.find, [search, options]).then(function(results){