org.codehaus.groovy.runtime
Class MethodRankHelper

java.lang.Object
  org.codehaus.groovy.runtime.MethodRankHelper

public class MethodRankHelper
extends Object

Utility class for MissingMethodException, MissingPropertyException etc. This class contains methods assisting in ranking and listing probable intended methods/fields when a exception is thrown.

Author:

Hjalmar Ekengren

Field Summary

static int	DL_CASE
static int	DL_DELETE
static int	DL_SUBSTITUTION
static int	DL_TRANSPOSITION
static int	MAX_CONSTRUCTOR_SCORE
static int	MAX_FIELD_SCORE
static int	MAX_METHOD_SCORE
static int	MAX_RECOMENDATIONS

Constructor Summary

MethodRankHelper()

Method Summary

protected static Class	boxVar(Class c) If c is a primitive class this method returns a boxed version otherwise c is returned.
static int	damerauLevenshteinDistance(Object[] s, Object[] t) This is a implementation of DL distance between two Object arrays instead of character streams.
static int	delDistance(CharSequence s, CharSequence t) This is a slightly modified version of the Damerau Levenshtein distance algorithm.
static String	getConstructorSuggestionString(Class type, Object[] arguments) Returns a string detailing possible solutions to a missing constructor if no good solutions can be found a empty string is returned.
static String	getMethodSuggestionString(String methodName, Class type, Object[] arguments) Returns a string detailing possible solutions to a missing method if no good solutions can be found a empty string is returned.
static String	getPropertySuggestionString(String fieldName, Class type) Returns a string detailing possible solutions to a missing field or property if no good solutions can be found a empty string is returned.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DL_SUBSTITUTION

public static final int DL_SUBSTITUTION

See Also:

Constant Field Values

DL_DELETE

public static final int DL_DELETE

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Constant Field Values

DL_TRANSPOSITION

public static final int DL_TRANSPOSITION

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Constant Field Values

DL_CASE

public static final int DL_CASE

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Constant Field Values

MAX_RECOMENDATIONS

public static final int MAX_RECOMENDATIONS

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Constant Field Values

MAX_METHOD_SCORE

public static final int MAX_METHOD_SCORE

See Also:

Constant Field Values

MAX_CONSTRUCTOR_SCORE

public static final int MAX_CONSTRUCTOR_SCORE

See Also:

Constant Field Values

MAX_FIELD_SCORE

public static final int MAX_FIELD_SCORE

See Also:

Constant Field Values

Constructor Detail

MethodRankHelper

public MethodRankHelper()

Method Detail

getMethodSuggestionString

public static String getMethodSuggestionString(String methodName,
                                               Class type,
                                               Object[] arguments)

Returns a string detailing possible solutions to a missing method if no good solutions can be found a empty string is returned.

Parameters:

methodName - the name of the method that doesn't exist

type - the class on which the method is invoked

arguments - the arguments passed to the method

Returns:

a string with probable solutions to the exception

getConstructorSuggestionString

public static String getConstructorSuggestionString(Class type,
                                                    Object[] arguments)

Returns a string detailing possible solutions to a missing constructor if no good solutions can be found a empty string is returned.

Parameters:

arguments - the arguments passed to the constructor

type - the class on which the constructor is invoked

Returns:

a string with probable solutions to the exception

getPropertySuggestionString

public static String getPropertySuggestionString(String fieldName,
                                                 Class type)

Returns a string detailing possible solutions to a missing field or property if no good solutions can be found a empty string is returned.

Parameters:

fieldName - the missing field

type - the class on which the field is sought

Returns:

a string with probable solutions to the exception

boxVar

protected static Class boxVar(Class c)

If c is a primitive class this method returns a boxed version otherwise c is returned. In java 1.5 this can be simplified thanks to the Type class.

Parameters:

c -

Returns:

a boxed version of c if c can be boxed, else c

delDistance

public static int delDistance(CharSequence s,
                              CharSequence t)

This is a slightly modified version of the Damerau Levenshtein distance algorithm. It has a additional test to see if a character has switched case, in the original algorithm this counts as a substitution. The "cost" for a substitution is given as 10 instead of 1 in this version, this enables transpositions and case modifications to have a lower cost than substitutions. Currently the lowercase versions of t_j and s_i isn't cached, its probable that some speed could be gained from this. This version is based on Chas Emerick's implementation of Levenshtein Distance for jakarta commons.

Parameters:

s - a CharSequence

t - the CharSequence to be compared to s

Returns:

a value representing the edit distance between s and t

damerauLevenshteinDistance

public static int damerauLevenshteinDistance(Object[] s,
                                             Object[] t)

This is a implementation of DL distance between two Object arrays instead of character streams. The objects are compared using their equals method. No objects may be null. This implementation is based on Chas Emerick's implementation of Levenshtein Distance for jakarta commons.

Parameters:

s - a Object array

t - this array is compared to s

Returns:

the edit distance between the two arrays