SemCheck

java.lang.Object
- jflex.SemCheck

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

Version:

JFlex 1.7.0

Field Summary

Fields
Modifier and Type Field Description

private static Macros macros

Constructor Summary

Constructors
Constructor Description

SemCheck()

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static void`	`check(RegExps rs, Macros m, 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

- Field Detail
  - macros
```
private static Macros macros
```
- Constructor Detail
  - SemCheck
```
public SemCheck()
```
- Method Detail
  - check
```
public static void check(RegExps rs,
                         Macros m,
                         java.io.File f)
```
    Performs semantic analysis for all expressions.
    Currently checks for empty expressions only.
    
    Parameters:
    
    rs - the reg exps to be checked
    
    m - the macro table (in expanded form)
    
    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.