Regular Expression Using Perl Perl Script Languages by ComputeNow - September 3, 2018September 3, 20180 Regular Expression Using Perl : Perl is the language that is the most famous for its use of regular expression for good reasons. We use the =~ operator to denote a match or an assignment depending upon the context. The use of !~ is to reverse the sense of the match. There are basically two regex operators
Angular Observables Tutorial Angular Script Languages by ComputeNow - September 2, 2018September 2, 20180 Angular Observables Angular Observables provide support for passing messages between publishers and subscribers in your application. Observables offer significant benefits over other techniques for event handling, asynchronous programming, and handling multiple values. Observables are declarative—that is, you define a function for publishing values, but it is not executed until a consumer subscribes to
Regular Expressions – (Regex) – Regular Expression Automata Theory by ComputeNow - September 2, 2018September 2, 20180 Regular Expressions was initially a term borrowed from automata theory in theoretical computer science. Broadly, it refers to patterns to which a sub-string needs to be matched. The comic should have already given you an idea of what regular expressions could be useful for. It should not be surprising that many programming languages, text processing
Context Free Grammars Automata Theory by ComputeNow - August 23, 2018August 23, 20180 Context free grammars (CFGs) are used to describe context-free languages. A context-free grammar is a set of recursive rules used to generate patterns of strings. A context-free grammar can describe all regular languages and more, but they cannot describe all possible languages. Context-free grammars are studied in fields of theoretical computer science, compiler design, and linguistics. CFG’s are
Translating Between Context-Free Grammars and Pushdown Automata Automata Theory by ComputeNow - August 19, 2018August 19, 20180 Context-free Grammar to Pushdown Automata Each derivation or sequence of production rules that results in a given string is made up of intermediate strings (which are made at each step of the derivation). The pushdown automata's nondeterminism helps it to guess the sequence of steps in the derivation that will result in the desired
Definition of Pushdown Automata Automata Theory by ComputeNow - August 17, 20180 Definition of Pushdown Automata Pushdown Automata is a finite automata with extra memory called stack which helps Pushdown automata to recognize Context Free Languages. A Pushdown Automata (PDA) can be defined as : Q is the set of states ∑ is the set of input symbols Γ is the set of pushdown symbols
Equivalence of Automata Automata Theory by ComputeNow - August 15, 20180 Equivalence of Automata Two automata A and B are said to be equivalent if both accept exactly the same set of input strings. Formally, if two automata A and B are equivalent then if there is a path from the start state of A to a final state of A labeled
Deterministic Finite Automata (DFA) Automata Theory by ComputeNow - August 13, 20180 Definition of Deterministic Finite Automata Deterministic Finite Automata (DFA) consists of 5 tuples {Q, ∑, q, F, δ}. Q : set of all states. ∑ : set of input symbols. ( Symbols which machine takes as input ) q : Initial state. ( Starting state of a machine ) F : set of final
Non Deterministic Finite Automata Automata Theory by ComputeNow - August 12, 20180 Non Deterministic Finite Automata (NDFA) If, for each pair of states and possible input chars, there is a unique next state (as specificed by the transitions), then the FA is deterministic (DFA). Otherwise, the FA is non deterministic finite automata (NDFA). What does it mean for an FA to have more than
What is Machine Learning? Machine Learning by ComputeNow - August 8, 20180 Machine learning (ML) is a category of algorithm that allows software applications to become more accurate in predicting outcomes without being explicitly programmed. The basic premise of machine learning is to build algorithms that can receive input data and use statistical analysis to predict an output while updating outputs as
