Ezhil (programming language)

Ezhil, in Tamil language script (எழில், ), is a compact, open source, interpreted, programming language, originally designed to enable native-Tamil speaking students, K-12 age-group to learn computer programming, and enable learning numeracy and computing, outside of linguistic expertise in predominately English language-based computer systems.

In the Ezhil programming language, Tamil keywords and language-grammar are chosen to easily enable the native Tamil speaker write programs in the Ezhil system. Ezhil allows easy representation of computer program closer to the Tamil language logical constructs equivalent to the conditional, branch and loop statements in modern English based programming languages. Ezhil is the first freely available programming language in the Tamil language and one of many known non-English-based programming languages. The language was officially announced in July 2009, while it has been developed since late 2007.

Description
The syntax of Ezhil is broadly similar to that of BASIC: blocks of code are run in sequential order, or via functions definitions, in a common control flow structures include, and. The termination of function block and statement blocks should have the termination keyword, similar to END in BASIC. Declarations are not necessary as Ezhil is a dynamic typed language, though type conversions must be made explicitly. Ezhil has built-in types for Numbers, Strings, Logicals and Lists.

Goals

 * Educational: Ezhil language is targeted toward K-12 students, and native-Tamil speakers, to learn elementary computer science principle
 * Intuitive: Ezhil language syntactic sugar is arranged to allow a sentence structure closer to the head final Tamil language, where the usual word order is SOV, in contrast to the SVO order of English.

Features

 * Arithmetic and logical operations, precedence indicated with parenthesis
 * Over 350+ builtins - many of them commonly found in the Python standard library
 * Procedural programming using functions, supporting recursion, call-by-value etc.
 * Ezhil as a language - it is not a macro-processor, and it is a complete compiler-front-end
 * Ezhil language has syntax highlighting support for Notepad++ and Emacs

Keywords
Conditional Statements are modeled after the IF-ELSEIF-ELSE statement. Loop control statements deriving from the WHILE statements are chosen. The function declaration syntax is kept simple. Details include the print statement, and the flow control statements below.

Type system
Ezhil has four basic types, for Numbers, Strings, Logicals and Lists. It does not allow creation of new types, being a procedural language without structures or objects.

Language - control structures, function declarations and operators grammar
Standard language grammar for control structures for Ezhil language is given below,

Operators
Standard logical operators, equality "==", inequality "!=", arithmetic comparison ">=", "<=",">","<" are supported. Arithmetic operators like "+","-","*","/" indicate standard plus, minus, product, division. Modulo is denoted by "%", and exponent by "^" characters.

Comments
'#' character denotes a single-line comment from the point to end-of-line. Multi-line comments are not defined.

Variable scoping, and visibility
Ezhil supports only call-by-value, and copies all data structures on function invocations. Globals are not supported. Recursion is supported and functions invocation copies variables.

Implementations
Current Ezhil implementation is tightly integrated with the Python runtime. Ezhil interpreter is based on a readline-like CLI, while it can also be run in a batch mode. The interactive mode consumes programs as UTF-8 encoded text and builds a tree, using a compiler front-end, to build an AST, and executes it using the Python objects build from this AST.

Hello world
The following is a Hello world program in Ezhil:

Guessing game
The following is a guessing game with 10-chances to guess a number between [1-100].

Turtle graphics
The following is a Turtle graphics based example to draw the Yin-Yang symbols.

Logo Ezhil

 * Logo for Ezhil language consists of interlaced letters of the Tamil language script, spelling out Ezhil - A Tamil programming language.