ANTLR

OUTLINE What is ANTLR? What exactly does ANTLR do? How ANTLR is installed to Eclipse? ANTLR Project Examples References

What is ANTLR? ANTLR - ANother Tool for Language Recognition tool that generates sophisticated parser generator using user defined grammars.. Using parser generators language interpreters Compilers other translators can be implemented. [1] ANTLR compiler generator or compiler compiler  used to generate the source code for language recognizers, analyzers translators from language specifications. [2]

What is ANTLR? ANTLR takes as its input a grammar - a precise description of a language augmented with semantic actions - generates source code files and other auxiliary files. Target language of the generated source code may be Java C/C++ C# Python Ruby is specified in the grammar [2].

What is ANTLR? ANTLR used to build translators and interpreters for Domain Specific Languages (DSLs). DSLs are very high level languages tailored to specific tasks. NASA uses Domain Specific Command Languages for space missions to improve reliability reduce risk reduce cost increase the speed of development. [1]

What exactly does ANTLR do? ANTLR reads a grammar  then generates these tools: A Lexer: This reads an input character or byte stream (i.e. characters, binary data, etc.) divides it into tokens using patterns you specify generates a token stream as output. Some tokens such as whitespace and comments as hidden using a protocol that ANTLR parsers automatically understand and respect. A Parser: This reads a token stream (normally generated by a lexer) matches phrases in your language via the rules (patterns) you specify typically performs some semantic action for each phrase (or sub-phrase) matched. [2]

What exactly does ANTLR do? Tool uses lexer and parser in series to check the word-level and phrase-level structure of the input if no fatal errors are encountered create an intermediate tree representation such as an Abstract Syntax Tree (AST) [2]

How ANTLR is installed to Eclipse? Tutorial for installation Installation of ANTLR to Eclipse

ANTLR Project Examples Tutorial for creating project Creating an ANTLR Project in Eclipse

English Sentence Example EnglishGrammer.g

English Sentence Example Test.java

English Sentence Example Sample Outputs :

English Sentence Example Parse trees:

Expression Language Example Expr.g

Expression Language Example Expr.g - Continue

Expression Language Example Test.java

Expression Language Example Test.java - Continue

Expression Language Example Sample Outputs :

REFERENCES [1] T. Parr, The Definitive ANTLR Reference, Building Domain-Specific Languges, Dallas, Texas : The Pragmatic Bookshelf , 2007 [2] Five minute introduction to ANTLR 3 : http://www.antlr.org/wiki/display/ANTLR3/Five+minute+introduction+to+ANTLR+3 [3] http://antlreclipse.sourceforge.net/ [4] http://vimeo.com/8001326 [5] http://www.antlr3.org/download/ [6] http://stackoverflow.com/questions/8343488/antlr-ide-in-eclipse-doesnt-work