ptolemy.math

Class Precision.VHDLPrecisionFormat

java.lang.Object

ptolemy.math.Precision.PrecisionFormat

ptolemy.math.Precision.VHDLPrecisionFormat

Enclosing class:

Precision

public static class Precision.VHDLPrecisionFormat
extends Precision.PrecisionFormat

Defines a Precision string format using the VHDL MSB:LSB precision format. The MSB value specifies the location of the most significant bit and LSB specifies the location of the least significant bit. Negative values are allowed for both MSB and LSB so long as the MSB is greater than the LSB.

This format supports the specification of either signed or unsigned values. The character 'U' must precede the MSB:LSB format to specify an unsigned value. An 'S' character may be applied to specify a signed number. If no 'U' or 'S' signed specification is provided, the precision will default to a signed value.

Parenthesis or brackets are optional around this specification. Examples:

• (2:3)
• (4:-3)
• [7:0]
• [-3:-8]
• 4:3

When printed, this format will always use parenthesis and only use the signed format specification for unsigned numbers (i.e. 'U' used for unsigned numbers and NO 'S' for signed numbers).

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	_regex Regular expression for IntegerFractionPrecisionFormat.

Fields inherited from class ptolemy.math.Precision.PrecisionFormat

COMMA_OR_FORWARDSLASH, OPTIONAL_L_PARAN, OPTIONAL_L_PARANBRACKET, OPTIONAL_R_PARAN, OPTIONAL_R_PARANBRACKET, OPTIONAL_U_OR_S_GROUP, OPTIONAL_WHITE_SPACE, PERIOD, SIGNED_INTEGER_GROUP, UNSIGNED_INTEGER_GROUP

Constructor Summary

Constructors

Constructor and Description
VHDLPrecisionFormat()

Method Summary

Modifier and Type	Method and Description
Precision	parseString(java.lang.String str) Parse the given String argument using the rules of the specific PrecisionFormat that is defined.
java.lang.String	printPrecisionFormat(Precision p) Creates a valid String representation of the Precision object based on the rules of the given string format.

Methods inherited from class ptolemy.math.Precision.PrecisionFormat

parseInteger, parseSignString

Methods inherited from class java.lang.Object

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

Field Detail

_regex

protected final java.lang.String _regex

Regular expression for IntegerFractionPrecisionFormat. Example ([US]{digit}:{digit})

See Also:

Constant Field Values

Constructor Detail

VHDLPrecisionFormat

public VHDLPrecisionFormat()

Method Detail

parseString

public Precision parseString(java.lang.String str)

Description copied from class: Precision.PrecisionFormat

Parse the given String argument using the rules of the specific PrecisionFormat that is defined. This method will return a valid Precision object from the String. If the String parsing does not produce a valid match, this method will return a null. If the String match is successful but there is a problem in the interpretation of the match, this method will throw a IllegalArgumentException.

Specified by:

parseString in class Precision.PrecisionFormat

Parameters:

str - String to parse

Returns:

A Precision object. Returns a null if the String does not match the particular string format.

printPrecisionFormat

public java.lang.String printPrecisionFormat(Precision p)

Description copied from class: Precision.PrecisionFormat

Creates a valid String representation of the Precision object based on the rules of the given string format. The format of this String should be consistent with the format used in the parseString method.

Specified by:

printPrecisionFormat in class Precision.PrecisionFormat

Parameters:

p - Precision object to represent as a String.

Returns:

String representing the Precision object