Package com.tonic.parser.util

Class DescriptorParser

java.lang.Object

com.tonic.parser.util.DescriptorParser

public final class DescriptorParser
extends Object

Static helpers for reading and building JVM field and method descriptors.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	DescriptorParser.ParseResult	One parsed type together with the number of descriptor characters it spans.

Method Summary

Modifier and Type	Method	Description
static int	getArgumentsAndReturnSize(String methodDescriptor)	Sums the argument slots and the return type slots.
static int	getArgumentsSize(String methodDescriptor)	Sums the local variable slots the arguments occupy, counting long and double as two.
static List<TypeInfo>	getArgumentTypes(String methodDescriptor)	Parses the parameter types between the parentheses.
static String	getMethodDescriptor(TypeInfo returnType, TypeInfo... paramTypes)	Builds a method descriptor from a return type and parameter types.
static String	getMethodDescriptor(TypeInfo returnType, List<TypeInfo> paramTypes)	Builds a method descriptor from a return type and a parameter list.
static TypeInfo	getReturnType(String methodDescriptor)	Extracts the return type following the closing parenthesis.
static int	getSize(String typeDescriptor)	Returns the slot width of a single type.
static boolean	isFieldDescriptor(String descriptor)	Tests whether a descriptor starts with a field type character.
static boolean	isMethodDescriptor(String descriptor)	Tests whether a descriptor has the shape of a method descriptor.
static DescriptorParser.ParseResult	parseTypeAt(String descriptor, int offset)	Parses the single type starting at an offset, recursing through array dimensions.

Methods inherited from class java.lang.Object

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

Method Detail

getArgumentTypes

public static List<TypeInfo> getArgumentTypes(String methodDescriptor)

Parses the parameter types between the parentheses.

Parameters:

methodDescriptor - the method descriptor

Returns:

the parameter types in order

Throws:

IllegalArgumentException - if the descriptor is null, does not open with '(', has no ')', or holds an unrecognized type

getReturnType

public static TypeInfo getReturnType(String methodDescriptor)

Extracts the return type following the closing parenthesis.

Parameters:

methodDescriptor - the method descriptor

Returns:

the return type

Throws:

IllegalArgumentException - if the descriptor is null, has no ')', or nothing follows it

getArgumentsSize

public static int getArgumentsSize(String methodDescriptor)

Sums the local variable slots the arguments occupy, counting long and double as two.

Parameters:

methodDescriptor - the method descriptor

Returns:

the argument slot count

Throws:

IllegalArgumentException - if the descriptor is malformed

getArgumentsAndReturnSize

public static int getArgumentsAndReturnSize(String methodDescriptor)

Sums the argument slots and the return type slots.

Parameters:

methodDescriptor - the method descriptor

Returns:

the combined slot count

Throws:

IllegalArgumentException - if the descriptor is malformed

getSize

public static int getSize(String typeDescriptor)

Returns the slot width of a single type.

Parameters:

typeDescriptor - a field type descriptor

Returns:

2 for long and double, 0 for void, otherwise 1

parseTypeAt

public static DescriptorParser.ParseResult parseTypeAt(String descriptor,
                                                       int offset)

Parses the single type starting at an offset, recursing through array dimensions.

Parameters:

descriptor - the descriptor to read from

offset - the character index the type starts at

Returns:

the parsed type and the characters it consumed

Throws:

IllegalArgumentException - if the offset is past the end, an object type is unterminated, or the type character is not recognized

getMethodDescriptor

public static String getMethodDescriptor(TypeInfo returnType,
                                         TypeInfo... paramTypes)

Builds a method descriptor from a return type and parameter types.

Parameters:

returnType - the return type

paramTypes - the parameter types in order

Returns:

the assembled descriptor

getMethodDescriptor

public static String getMethodDescriptor(TypeInfo returnType,
                                         List<TypeInfo> paramTypes)

Builds a method descriptor from a return type and a parameter list.

Parameters:

returnType - the return type

paramTypes - the parameter types in order

Returns:

the assembled descriptor

isMethodDescriptor

public static boolean isMethodDescriptor(String descriptor)

Tests whether a descriptor has the shape of a method descriptor.

Parameters:

descriptor - the descriptor to test, may be null

Returns:

true if it opens with '(' and contains ')'

isFieldDescriptor

public static boolean isFieldDescriptor(String descriptor)

Tests whether a descriptor starts with a field type character.

Parameters:

descriptor - the descriptor to test, may be null

Returns:

true if it begins with an object, array or primitive type character