Overview | Package | Class | Use | Tree | Deprecated | Index | Help
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

## org.basex.query.ft
Class FTExpr

    java.lang.Object
      org.basex.query.ExprInfo
          org.basex.query.expr.Expr
              org.basex.query.ft.FTExpr

Direct Known Subclasses:
  FTAnd, FTContent, FTDistance, FTMildNot, FTNot, FTOptions, FTOr, FTOrder, FTScope, FTWeight, FTWindow, FTWords

    public abstract class FTExpr

extends Expr

This class defines is an abstract class for full-text expressions.

Author:
  Workgroup DBIS, University of Konstanz 2005-10, ISC License, Christian Gruen

Nested Class Summary

Nested classes/interfaces inherited from class org.basex.query.expr.Expr
`Expr.Use`

Field Summary
`FTExpr[]` | `expr` Expression list.

Method Summary
`abstract FTItem` | `atomic(QueryContext ctx)` This method is called by the sequential full-text evaluation.
`String` | `color()` Returns a color string for the expression.
`FTExpr` | `comp(QueryContext ctx)` Optimizes and compiles the expression.
`FTExpr` | `indexEquivalent(IndexContext ic)` Returns an equivalent expression which accesses an index structure.
`abstract FTIter` | `iter(QueryContext ctx)` This method is called by the index-based full-text evaluation.
`void` | `plan(Serializer ser)` Recursively sends the abstract syntax of this expression to the specified serializer.
`boolean` | `removable(Var v, QueryContext ctx)` Checks if the specified variable is removable.
`FTExpr` | `remove(Var v)` Removes the specified variable in a sub expression.
`Return` | `returned(QueryContext ctx)` Indicates the return type of an expression.
`boolean` | `uses(Expr.Use u, QueryContext ctx)` Indicates if an expression uses the specified type.

Methods inherited from class org.basex.query.expr.Expr
`addText, checkCtx, checkDbl, checkItr, duplicates, e, ebv, i, indexAccessible, sameAs, size, test, v`

Methods inherited from class org.basex.query.ExprInfo
`info, name, toString`

Methods inherited from class java.lang.Object
`equals, getClass, hashCode, notify, notifyAll, wait, wait, wait`

Field Detail

### expr

    public FTExpr[] expr

  Expression list.

Method Detail

### comp

    public FTExpr comp(QueryContext ctx)
                throws QueryException

  Description copied from class: `Expr`
  Optimizes and compiles the expression.

  Specified by:
    `comp` in class `Expr`
  Parameters:
    `ctx` - query context
  Returns:
    optimized Expression
  Throws:
    `QueryException` - query exception

### atomic

    public abstract FTItem atomic(QueryContext ctx)
                           throws QueryException

  This method is called by the sequential full-text evaluation.

  Overrides:
    `atomic` in class `Expr`
  Parameters:
    `ctx` - query context
  Returns:
    resulting item
  Throws:
    `QueryException` - query exception

### iter

    public abstract FTIter iter(QueryContext ctx)
                         throws QueryException

  This method is called by the index-based full-text evaluation.

  Overrides:
    `iter` in class `Expr`
  Parameters:
    `ctx` - query context
  Returns:
    resulting item
  Throws:
    `QueryException` - query exception

### uses

    public final boolean uses(Expr.Use u,
                              QueryContext ctx)

  Description copied from class: `Expr`
  Indicates if an expression uses the specified type. Called by the compiler to perform certain optimizations. `true` is returned by default and thus assumed as "worst-case".

  Specified by:
    `uses` in class `Expr`
  Parameters:
    `u` - use type to be checked
    `ctx` - query context
  Returns:
    result of check

### removable

    public boolean removable(Var v,
                             QueryContext ctx)

  Description copied from class: `Expr`
  Checks if the specified variable is removable.

  Overrides:
    `removable` in class `Expr`
  Parameters:
    `v` - variable to be removed
    `ctx` - query context
  Returns:
    result of check

### remove

    public FTExpr remove(Var v)

  Description copied from class: `Expr`
  Removes the specified variable in a sub expression.

  Overrides:
    `remove` in class `Expr`
  Parameters:
    `v` - variable to be removed
  Returns:
    expression with removed variable

### returned

    public final Return returned(QueryContext ctx)

  Description copied from class: `Expr`
  Indicates the return type of an expression. Called by the compiler to check if expressions can be reformulated. null is returned by default.

  Overrides:
    `returned` in class `Expr`
  Parameters:
    `ctx` - query context
  Returns:
    result of check

### indexEquivalent

    public FTExpr indexEquivalent(IndexContext ic)
                           throws QueryException

  Description copied from class: `Expr`
  Returns an equivalent expression which accesses an index structure. Must be called if `Expr.indexAccessible(org.basex.query.IndexContext)` is implemented for an expression.

  Overrides:
    `indexEquivalent` in class `Expr`
  Parameters:
    `ic` - index context
  Returns:
    Equivalent index-expression or null
  Throws:
    `QueryException` - query exception

### color

    public final String color()

  Description copied from class: `ExprInfo`
  Returns a color string for the expression.

  Overrides:
    `color` in class `ExprInfo`
  Returns:
    color

### plan

    public void plan(Serializer ser)
              throws IOException

  Description copied from class: `ExprInfo`
  Recursively sends the abstract syntax of this expression to the specified serializer.

  Specified by:
    `plan` in class `ExprInfo`
  Parameters:
    `ser` - serializer
  Throws:
    `IOException` - I/O exception

Overview | Package | Class | Use | Tree | Deprecated | Index | Help
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD