Building efficient incremental LL parsers by augmenting LL tables and threading parse trees

Abstract

Incremental parsing is widely used in language-based editors and incremental compiling and interpreting environments. Re-parsing of modified input strings is the most frequently performed operation in these environments. Its efficiency can greatly affect the success of these environments. This paper describes the introduction of a threaded link in parse trees and an additional distance entry in LL parse tables to support minimal LL(1) re-parsing. These enhancements are then used to produce an efficient incremental LL parser.