Package org.python.core.stringlib
Class InternalFormat.Spec
- java.lang.Object
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- org.python.core.stringlib.InternalFormat.Spec
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- Enclosing class:
- InternalFormat
public static class InternalFormat.Spec extends java.lang.Object
Parsed PEP-3101 format specification of a single field, encapsulating the format for use by formatting methods. This class holds the several attributes that might be decoded from a format specifier. Each attribute has a reserved value used to indicate "unspecified".Spec
objects may be merged such that oneSpec
provides values, during the construction of a newSpec
, for attributes that are unspecified in a primary source.This structure is returned by factory method
InternalFormat.fromText(String)
, and having public final members is freely accessed by formatters such asFloatFormatter
, and the __format__ methods of client object types.The fields correspond to the elements of a format specification. The grammar of a format specification is:
[[fill]align][sign][#][0][width][,][.precision][type]
A typical idiom is:private static final InternalFormatSpec FLOAT_DEFAULTS = InternalFormatSpec.from(">"); ... InternalFormat.Spec spec = InternalFormat.fromText(specString); spec = spec.withDefaults(FLOAT_DEFAULTS); ... // Validation of spec.type, and other attributes, for this type. FloatFormatter f = new FloatFormatter(spec); String result = f.format(value).getResult();
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Field Summary
Fields Modifier and Type Field Description char
align
Alignment indicator is one of {'<', '^', '>', '='
, or U+FFFF if unspecified.boolean
alternate
The alternative format flag '#' was given.char
fill
The fill character specified, or U+FFFF if unspecified.boolean
grouping
Insert the grouping separator (which in Python always indicates a group-size of 3).static char
NONE
Non-character code point used to represent "no value" inchar
attributes.static InternalFormat.Spec
NUMERIC
Defaults applicable to most numeric types.int
precision
Precision decoded from the format, or -1 if unspecified.char
sign
Sign-handling flag, one of'+'
,'-'
, or' '
, or U+FFFF if unspecified.static InternalFormat.Spec
STRING
Defaults applicable to string types.char
type
Type key from the format, or U+FFFF if unspecified.static int
UNSPECIFIED
Negative value used to represent "no value" inint
attributes.int
width
Width to which to pad the result, or -1 if unspecified.
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Constructor Summary
Constructors Constructor Description Spec(char fill, char align, char sign, boolean alternate, int width, boolean grouping, int precision, char type)
Constructor to set all the fields in the format specifier.Spec(int precision, char type)
Constructor offering just precision and type.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description char
getAlign(char defaultAlign)
The alignment from the parsed format specification, or default.char
getFill(char defaultFill)
The alignment from the parsed format specification, or default.int
getPrecision(int defaultPrecision)
The precision from the parsed format specification, or default.char
getType(char defaultType)
The type code from the parsed format specification, or default supplied.static boolean
specified(char c)
Test to see if an attribute has been specified.static boolean
specified(int value)
Test to see if an attribute has been specified.java.lang.String
toString()
Return a format specifier (text) equivalent to the value of this Spec.InternalFormat.Spec
withDefaults(InternalFormat.Spec other)
Return a mergedSpec
object, in which any attribute of this object that is specified (ortrue
), has the same value in the result, and any attribute of this object that is unspecified (orfalse
), has the value that attribute takes in the other object.
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Field Detail
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fill
public final char fill
The fill character specified, or U+FFFF if unspecified.
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align
public final char align
Alignment indicator is one of {'<', '^', '>', '='
, or U+FFFF if unspecified.
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sign
public final char sign
Sign-handling flag, one of'+'
,'-'
, or' '
, or U+FFFF if unspecified.
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alternate
public final boolean alternate
The alternative format flag '#' was given.
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width
public final int width
Width to which to pad the result, or -1 if unspecified.
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grouping
public final boolean grouping
Insert the grouping separator (which in Python always indicates a group-size of 3).
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precision
public final int precision
Precision decoded from the format, or -1 if unspecified.
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type
public final char type
Type key from the format, or U+FFFF if unspecified.
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NONE
public static final char NONE
Non-character code point used to represent "no value" inchar
attributes.- See Also:
- Constant Field Values
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UNSPECIFIED
public static final int UNSPECIFIED
Negative value used to represent "no value" inint
attributes.- See Also:
- Constant Field Values
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NUMERIC
public static final InternalFormat.Spec NUMERIC
Defaults applicable to most numeric types. Equivalent to " >"
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STRING
public static final InternalFormat.Spec STRING
Defaults applicable to string types. Equivalent to " <"
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Constructor Detail
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Spec
public Spec(char fill, char align, char sign, boolean alternate, int width, boolean grouping, int precision, char type)
Constructor to set all the fields in the format specifier.[[fill]align][sign][#][0][width][,][.precision][type]
- Parameters:
fill
- fill character (orNONE
align
- alignment indicator, one of {'<', '^', '>', '='
sign
- policy, one of'+'
,'-'
, or' '
.alternate
- true to request alternate formatting mode ('#'
flag).width
- of field after padding or -1 to defaultgrouping
- true to request comma-separated groupsprecision
- (e.g. decimal places) or -1 to defaulttype
- indicator character
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Spec
public Spec(int precision, char type)
Constructor offering just precision and type.[.precision][type]
- Parameters:
precision
- (e.g. decimal places)type
- indicator character
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Method Detail
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specified
public static final boolean specified(char c)
Test to see if an attribute has been specified.- Parameters:
c
- attribute- Returns:
- true only if the attribute is not equal to
NONE
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specified
public static final boolean specified(int value)
Test to see if an attribute has been specified.- Parameters:
value
- of attribute- Returns:
- true only if the attribute is >=0 (meaning that it has been specified).
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toString
public java.lang.String toString()
Return a format specifier (text) equivalent to the value of this Spec.- Overrides:
toString
in classjava.lang.Object
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withDefaults
public InternalFormat.Spec withDefaults(InternalFormat.Spec other)
Return a mergedSpec
object, in which any attribute of this object that is specified (ortrue
), has the same value in the result, and any attribute of this object that is unspecified (orfalse
), has the value that attribute takes in the other object. Thus the second object supplies default values. (These defaults may also be unspecified.) The use of this method is to allow aSpec
constructed from text to record exactly, and only, what was in the textual specification, while the __format__ method of a client object supplies its type-specific defaults. Thus "20" means "<20s" to astr
, ">20.12" to afloat
and ">20.12g" to acomplex
.- Parameters:
other
- defaults to merge where this object does not specify the attribute.- Returns:
- a new Spec object.
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getFill
public char getFill(char defaultFill)
The alignment from the parsed format specification, or default.
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getAlign
public char getAlign(char defaultAlign)
The alignment from the parsed format specification, or default.
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getPrecision
public int getPrecision(int defaultPrecision)
The precision from the parsed format specification, or default.
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getType
public char getType(char defaultType)
The type code from the parsed format specification, or default supplied.
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