EcoSL

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EcoSL
Economical Spreadsheet Language
Lalit K Kanteti Somenath Srinivas
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Feeling like this??
Image from www.spreadsheet-factory.com/presentati
on.html
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We have EcoSL for you!!
Image from www.spreadsheet-factory.com/presentati
on.html
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Whats this Language?

• A language which allows users to manipulate on
  sets of data in a spreadsheet like manner
• Key features of Spreadsheets Data
  Interpretations
• Software should be more than Scientific Cal
• Mathematical Computations on data
• Graphical representations
• No need to know too much of Programming concepts
• EcoSL was motivated and had started with above
  goals
• EcoSL is not a compiler. Its an Interpreter

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Tired of hello world? Lets have some different
fodder for the newbie!

• /
• A Sample program
• /
• func max(a,b)
• if (agtb)?
• return a
• else
• return b
• 12 2
• 35 6
• max(5,99)
• c max(5,99)
• println(c)
• print(max(12,35))

• The adjacent sample program prints the following
  output
• 99
• 6

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Does the previous code look cool. Guess why???

• EcoSL is characterized by a simple syntax.
• xy defines a basic unit of computation in a
  spreadsheet called a cell
• Not to annoy the seasoned programmer we also
  support the traditional identifiers.
• Built in functions of Sigma, Avg, Print, Println
• In addition the user can easily define any
  function
• of his choice
• Observe
• No declarations for identifiers
• No return type defined for functions
• Built-in functions synonymous to mathematical
  operations

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EcoSL-Lexer

• Converts stream of program input to tokens
• An example comment matching rule
• COMMENT "/" ( options
  generateAmbigWarnings false LA(2) ! '/'
  ? ''
• "\r\n" newline()
• ( '\r' '\n' ) newline()
• ( '' '\r' '\n' )?
• ) "/" setType(Token.SKIP)

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Ecosl Parser

• Our entry point into the parser is shown below
• program LBRACE! (statement)
• RBRACE!
• program (PROGRAM,
• "program", program)
• Some key parser productions
• Statement
• (LBRACE! (statement)
• RBRACE!)
• statement (STMT_BLOCK,
• "stmt_block",
  statement) )

• Contd
• func_decl
• "func"! ID LPAREN! (formal_args)
• RPAREN! LBRACE! (statement)
• RBRACE!
• func_decl (FUNC_DECL,
• "func_decl", func_decl)
• coordinate
• LBRAC! (expr) COLON! (expr) RBRAC!
• coordinate (COORDINATE,
• "coordinate" , coordinate)

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Walker Ecosl runs!!!

• program returns Program prog
• prognullStmt s null
• (PROGRAM prog new Program()
• (s statement
• prog.addStmt(s)
  
• )
• )
• (FUNC_DECL ID (argsformal_args)?
• s1 new StmtBlock()
• (s2statement
  ((StmtBlock)s1).addStmt(s2)
  
• )
• s new FunctionDecl (ID.getText(), args,
  s1)

• formal_args returns java.util.Vector formalArgs
• formalArgs null
• (FORMAL_ARGS formalArgs
  new java.util.Vector() (ID formalArgs.add
  (new Variable(ID.getText())) ))
• (COORDINATE aexpr bexpr
• e new Coordinate(a, b)
• )

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Program
Statements
Expr Statement
While
For
Break
If
Continue
.........
Plus
Minus
Mod
Func Call
Variable
IntConstant
...........
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Looking for the same old features?? It is there
in EcoSL!!

• User defined functions
• Built-in functions
• Iterations (while, for)?
• Comments
• Conditional statements (if else)?
• Scope
• Data types (Integer, float)?
• Basic arithmetic operations
• Break,continue

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Looking for the something new?? It is there in
EcoSL!!

• Coordinates
• Operations on coordinates
• String operations
• No types
• Functions returns

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Problem in coordination??

• We have a repository!!!!!!!!!!
• CVS through Clic machines
• Google Code (svn)

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Thanks!!!!!

• Let's explore EcoSL.
• Time for Demo!!!!