SemCheck

java.lang.Object
- jflex.core.SemCheck

```
public final class SemCheck
extends java.lang.Object
```
Performs simple semantic analysis on regular expressions.

Version:

JFlex 1.9.1

Constructor Summary

Constructors
Modifier Constructor Description

private SemCheck()
Prevent instantiation of static-only class

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static void`	`check(RegExps rs, java.io.File f)`	Performs semantic analysis for all expressions.
`static boolean`	`isFiniteChoice(RegExp re)`	Returns true iff the expression is a finite choice of fixed length expressions.
`static int`	`length(RegExp re)`	Returns length if expression has fixed length, -1 otherwise.
`static boolean`	`maybeEmtpy(RegExp re)`	Checks if the expression potentially matches the empty string.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - SemCheck
```
private SemCheck()
```
    Prevent instantiation of static-only class
- Method Detail
  - check
```
public static void check(RegExps rs,
                         java.io.File f)
```
    Performs semantic analysis for all expressions.
    Currently checks for empty expressions only.
    
    Parameters:
    
    rs - the reg exps to be checked
    
    f - the spec file containing the rules
  - maybeEmtpy
```
public static boolean maybeEmtpy(RegExp re)
```
    Checks if the expression potentially matches the empty string.
    
    Parameters:
    
    re - a RegExp object.
    
    Returns:
    
    a boolean.
  - length
```
public static int length(RegExp re)
```
    Returns length if expression has fixed length, -1 otherwise.
    Negation operators are treated as always variable length.
    
    Parameters:
    
    re - a RegExp object.
    
    Returns:
    
    a int.
  - isFiniteChoice
```
public static boolean isFiniteChoice(RegExp re)
```
    Returns true iff the expression is a finite choice of fixed length expressions.
    Negation operators are treated as always variable length.
    
    Parameters:
    
    re - a RegExp object.
    
    Returns:
    
    a boolean.