Grammar (Palladio Core)

All Known Implementing Classes:

DefaultXMLGrammar
```
public interface Grammar
```
Object of this class provides the grammar rules for parsing the expression. Parser uses this class to parse the string expression in list of Expression Tokens, and Compiler uses it to build the expression tree.

Version:

1.0

Author:

Mohit Gupta, Parmod Kamboj

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`addFunction(String functionName)` Use this method to add any function identification to the grammar.
`String`	`getOppositeBracket(String bracket)` Returns the opposite bracket for the given bracket.
`int`	`getPrecedenceOrder(ExpressionToken operator, boolean isUnary)` Gets the precedence order of the given operator
`int`	`getPrecedenceOrder(String operator, boolean isUnary)` Gets the precedence order of the given operator
`boolean`	`isAllowed(String token)` Checks whether the token is allowed or not.
`boolean`	`isApproachable(String token)` Checks whether the given token is approachable using any of the pattern or not.
`boolean`	`isBinaryOperator(ExpressionToken token)` Checks whether the given token is a binary operator or not.
`boolean`	`isBinaryOperator(String token)` Checks whether the given token is a binary operator or not.
`boolean`	`isBracket(ExpressionToken token)` Check whether the given token is a bracket or not.
`boolean`	`isBracket(String token)` Check whether the given token is a bracket or not.
`boolean`	`isDelimiter(ExpressionToken token)` Checks whether the token is a delimiter or not.
`boolean`	`isDelimiter(String token)` Checks whether the token is a delimiter or not.
`boolean`	`isFunction(ExpressionToken token)` Checks whether the token is an function or not.
`boolean`	`isFunction(String token)` Checks whether the token is an function or not.
`boolean`	`isIgnoreBlank()` Checks whether to ignore the blanks in expression or not.
`boolean`	`isLeftBracket(ExpressionToken token)` Checks whether the token is a left bracket or not.
`boolean`	`isLeftBracket(String token)` Checks whether the token is a left bracket or not.
`boolean`	`isOperator(ExpressionToken token)` Checks whether the given token is an operator or not.
`boolean`	`isOperator(String token)` Checks whether the given token is an operator or not.
`boolean`	`isRightBracket(ExpressionToken token)` Checks whether the token is a right bracket or not.
`boolean`	`isRightBracket(String token)` Checks whether the token is a right bracket or not.
`boolean`	`isUnary(ExpressionToken operator)` Checks whether the given operator is a unary operator or not.
`boolean`	`isUnary(String operator)` Checks whether the given operator is a unary operator or not.

- Method Detail
  - isDelimiter
```
boolean isDelimiter(ExpressionToken token)
```
    Checks whether the token is a delimiter or not.
    
    Parameters:
    
    token - the token
    
    Returns:
    
    true if the token is delimiter false otherwise.
  - isDelimiter
```
boolean isDelimiter(String token)
```
    Checks whether the token is a delimiter or not.
    
    Parameters:
    
    token - the token
    
    Returns:
    
    true if the token is delimiter false otherwise.
  - isApproachable
```
boolean isApproachable(String token)
```
    Checks whether the given token is approachable using any of the pattern or not. Given token can be partially or fully constructed token during parsing process. Parser generally calls this method to check whether the current token can be combined with next character of expression to form some meaningful token or not. If not, then it utilize the existing collected characters as one token, otherwise it keep collecting characters.
    
    Parameters:
    
    token - the token, partially or full constructed, to check whether it can approach to any expression token pattern or not.
    
    Returns:
    
    true if the token pattern is approachable false otherwise.
  - isAllowed
```
boolean isAllowed(String token)
```
    Checks whether the token is allowed or not. A token is fully constructed token. Parser generally calls this method to check whether the current token is a valid token as per the production rules or not.
    
    Parameters:
    
    token - the token which is to be checked for its validity
    
    Returns:
    
    true if the token is allowed false otherwise.
  - isOperator
```
boolean isOperator(ExpressionToken token)
```
    Checks whether the given token is an operator or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token is an operator false otherwise
  - isOperator
```
boolean isOperator(String token)
```
    Checks whether the given token is an operator or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token is an operator false otherwise
  - isFunction
```
boolean isFunction(ExpressionToken token)
```
    Checks whether the token is an function or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token is an function false otherwise
  - isFunction
```
boolean isFunction(String token)
```
    Checks whether the token is an function or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token is an function false otherwise
  - addFunction
```
void addFunction(String functionName)
```
    Use this method to add any function identification to the grammar. Grammar implementation will generally load the function identification itself from some configuration file. Like, in case of DefaultXMLGrammar implementation, it is loaded from grammar.xml. However, developer may opt to add functions using API also.
    
    Parameters:
    
    functionName - name of the function to add
  - isBinaryOperator
```
boolean isBinaryOperator(ExpressionToken token)
```
    Checks whether the given token is a binary operator or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token is a binary operator false otherwise
  - isBinaryOperator
```
boolean isBinaryOperator(String token)
```
    Checks whether the given token is a binary operator or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token is a binary operator false otherwise
  - isUnary
```
boolean isUnary(ExpressionToken operator)
```
    Checks whether the given operator is a unary operator or not.
    
    Parameters:
    
    operator - the operator to check
    
    Returns:
    
    true if the operator is used as unary operator false otherwise.
  - isUnary
```
boolean isUnary(String operator)
```
    Checks whether the given operator is a unary operator or not.
    
    Parameters:
    
    operator - the operator to check
    
    Returns:
    
    true if the operator is used as unary operator false otherwise.
  - getPrecedenceOrder
```
int getPrecedenceOrder(ExpressionToken operator,
                       boolean isUnary)
```
    Gets the precedence order of the given operator
    
    Parameters:
    
    operator - the operator to check for precedence
    
    isUnary - true if the operator is unary, as an operator can behave either as unary or as binary
    
    Returns:
    
    the precedence order of the operator
  - getPrecedenceOrder
```
int getPrecedenceOrder(String operator,
                       boolean isUnary)
```
    Gets the precedence order of the given operator
    
    Parameters:
    
    operator - the operator to check for precedence
    
    isUnary - true if the operator is unary, as an operator can behave either as unary or as binary
    
    Returns:
    
    the precedence order of the operator
  - isLeftBracket
```
boolean isLeftBracket(ExpressionToken token)
```
    Checks whether the token is a left bracket or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token can be used as left bracket false otherwise.
  - isLeftBracket
```
boolean isLeftBracket(String token)
```
    Checks whether the token is a left bracket or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token can be used as left bracket false otherwise.
  - isRightBracket
```
boolean isRightBracket(ExpressionToken token)
```
    Checks whether the token is a right bracket or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token can be used as right bracket false otherwise.
  - isRightBracket
```
boolean isRightBracket(String token)
```
    Checks whether the token is a right bracket or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token can be used as right bracket false otherwise.
  - isBracket
```
boolean isBracket(ExpressionToken token)
```
    Check whether the given token is a bracket or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token is a bracket false otherwise
  - isBracket
```
boolean isBracket(String token)
```
    Check whether the given token is a bracket or not.
    
    Parameters:
    
    token - the token to check
    
    Returns:
    
    true if the token is a bracket false otherwise
  - getOppositeBracket
```
String getOppositeBracket(String bracket)
```
    Returns the opposite bracket for the given bracket.
    
    Parameters:
    
    bracket - the bracket for which we need to find the opposite bracket
    
    Returns:
    
    the opposite part of bracket w.r.t given bracket
  - isIgnoreBlank
```
boolean isIgnoreBlank()
```
    Checks whether to ignore the blanks in expression or not. It tells the parser whether to exclude the extra blanks while parsing or not.
    
    Returns:
    
    true if parser wants to exclude the blanks false otherwise.

Interface Grammar

Method Summary

Method Detail

isDelimiter

isDelimiter

isApproachable

isAllowed

isOperator

isOperator

isFunction

isFunction

addFunction

isBinaryOperator

isBinaryOperator

isUnary

isUnary

getPrecedenceOrder

getPrecedenceOrder

isLeftBracket

isLeftBracket

isRightBracket

isRightBracket

isBracket

isBracket

getOppositeBracket

isIgnoreBlank