age

Pop	59.51
Vit	3.77

Kelbt generates backtracking LALR parsers. A distinguishing characteristic of Kelbt is that it introduces a class of actions called undo actions which are invoked as the backtracker undoes parsing. These allow the user to revert any side effects of forward parsing. Kelbt enables a user-controlled parsing strategy approximating that of generalized recursive-descent parsing. This makes it easy to resolve language ambiguities by ordering the grammar productions of a nonterminal according to precedence.

Pop	223.44
Vit	14.78

Ragel compiles finite state machines from regular languages into C, C++, Objective-C, D, Java, or Ruby code. It allows the programmer to embed actions at any point in a regular language, and to control non-determinism in the resulting machines. It understands concatenation, union, kleene star, subtraction, intersection, epsilon transitions, and various other common operators. It also supports the construction of scanners and the building of state machines using state charts. It can be used to create very fast recognizers and parsers that are also robust.