Class Literals
- java.lang.Object
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- org.scijava.parse.Literals
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public final class Literals extends java.lang.Object
Utility methods for parsing literals from strings. These methods largely conform to the Java specification's ideas of what constitutes a numeric or string literal.- Author:
- Curtis Rueden
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Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static java.lang.Number
parseBinary(java.lang.CharSequence s)
Parses a binary literal (e.g.,0b010101000011
).static java.lang.Number
parseBinary(java.lang.CharSequence s, Position pos)
Parses a binary literal (e.g.,0b010101000011
).static java.lang.Boolean
parseBoolean(java.lang.CharSequence s)
Parses a boolean literal (i.e., true and false).static java.lang.Boolean
parseBoolean(java.lang.CharSequence s, Position pos)
Parses a boolean literal (i.e., true and false).static java.lang.Number
parseDecimal(java.lang.CharSequence s)
Parses a decimal literal (integer or otherwise; e.g.,1234567890
,1234.0987
or1.2e34
).static java.lang.Number
parseDecimal(java.lang.CharSequence s, Position pos)
Parses a decimal literal (e.g.,1234.0987
or1.2e34
).static java.lang.Number
parseHex(java.lang.CharSequence s)
Parses a hexidecimal literal (e.g.,0xfedcba9876543210
).static java.lang.Number
parseHex(java.lang.CharSequence s, Position pos)
Parses a hexidecimal literal (e.g.,0xfedcba9876543210
).static java.lang.Object
parseLiteral(java.lang.CharSequence s)
Parses a literal of any known type (booleans, strings and numbers).static java.lang.Object
parseLiteral(java.lang.CharSequence s, Position pos)
Parses a literal of any known type (booleans, strings and numbers).static java.lang.Number
parseNumber(java.lang.CharSequence s)
Parses a numeric literal of any known type.static java.lang.Number
parseNumber(java.lang.CharSequence s, Position pos)
Parses a numeric literal of any known type.static java.lang.Number
parseOctal(java.lang.CharSequence s)
Parses an octal literal (e.g.,01234567
).static java.lang.Number
parseOctal(java.lang.CharSequence s, Position pos)
Parses an octal literal (e.g.,01234567
).static java.lang.String
parseString(java.lang.CharSequence s)
Parses a string literal which is enclosed in single or double quotes.static java.lang.String
parseString(java.lang.CharSequence s, Position pos)
Parses a string literal which is enclosed in single or double quotes.
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Method Detail
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parseBoolean
public static java.lang.Boolean parseBoolean(java.lang.CharSequence s)
Parses a boolean literal (i.e., true and false).- Parameters:
s
- The string from which the boolean literal should be parsed.- Returns:
- The parsed boolean value—either
Boolean.TRUE
orBoolean.FALSE
— or null if the string does not begin with a boolean literal.
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parseString
public static java.lang.String parseString(java.lang.CharSequence s)
Parses a string literal which is enclosed in single or double quotes.For literals in double quotes, this parsing mechanism is intended to be as close as possible to the numeric literals supported by the Java programming language itself. Literals in single quotes are completely verbatim, with no escaping performed.
- Parameters:
s
- The string from which the string literal should be parsed.- Returns:
- The parsed string value, unescaped according to Java conventions. Returns null if the string does not begin with a single or double quote.
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parseHex
public static java.lang.Number parseHex(java.lang.CharSequence s)
Parses a hexidecimal literal (e.g.,0xfedcba9876543210
).- Parameters:
s
- The string from which the numeric literal should be parsed.- Returns:
- The parsed numeric value—an
Integer
if sufficiently small, or aLong
if needed or if theL
suffix is given; or aBigInteger
if the value is too large even forlong
.
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parseBinary
public static java.lang.Number parseBinary(java.lang.CharSequence s)
Parses a binary literal (e.g.,0b010101000011
).- Parameters:
s
- The string from which the numeric literal should be parsed.- Returns:
- The parsed numeric value—an
Integer
if sufficiently small, or aLong
if needed or if theL
suffix is given; or aBigInteger
if the value is too large even forlong
.
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parseOctal
public static java.lang.Number parseOctal(java.lang.CharSequence s)
Parses an octal literal (e.g.,01234567
).- Parameters:
s
- The string from which the numeric literal should be parsed.- Returns:
- The parsed numeric value—an
Integer
if sufficiently small, or aLong
if needed or if theL
suffix is given; or aBigInteger
if the value is too large even forlong
.
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parseDecimal
public static java.lang.Number parseDecimal(java.lang.CharSequence s)
Parses a decimal literal (integer or otherwise; e.g.,1234567890
,1234.0987
or1.2e34
).- Parameters:
s
- The string from which the numeric literal should be parsed.- Returns:
- The parsed numeric value, of a type consistent with Java's support
for numeric primitives—or for values outside the normal range
of Java primitives,
BigInteger
orBigDecimal
as appropriate. Returns null if the string does not begin with the numeric literal telltale of a 0-9 digit with optional minus.
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parseNumber
public static java.lang.Number parseNumber(java.lang.CharSequence s)
Parses a numeric literal of any known type.This parsing mechanism is intended to be as close as possible to the numeric literals supported by the Java programming language itself.
- Parameters:
s
- The string from which the numeric literal should be parsed.- Returns:
- The parsed numeric value, of a type consistent with Java's support
for numeric primitives—or for values outside the normal range
of Java primitives,
BigInteger
orBigDecimal
as appropriate. Returns null if the string does not begin with the numeric literal telltale of a 0-9 digit with optional minus.
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parseLiteral
public static java.lang.Object parseLiteral(java.lang.CharSequence s)
Parses a literal of any known type (booleans, strings and numbers).- Parameters:
s
- The string from which the literal should be parsed.- Returns:
- The parsed value, of a type consistent with Java's support for
literals: either
Boolean
,String
or a concreteNumber
subclass. Returns null if the string does not match the syntax of a known literal. - See Also:
parseBoolean(CharSequence)
,parseString(CharSequence)
,parseNumber(CharSequence)
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parseBoolean
public static java.lang.Boolean parseBoolean(java.lang.CharSequence s, Position pos)
Parses a boolean literal (i.e., true and false).- Parameters:
s
- The string from which the boolean literal should be parsed.pos
- The offset from which the literal should be parsed. If parsing is successful, the position will be advanced to the next index after the parsed literal.- Returns:
- The parsed boolean value—either
Boolean.TRUE
orBoolean.FALSE
— or null if the string does not begin with a boolean literal.
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parseString
public static java.lang.String parseString(java.lang.CharSequence s, Position pos)
Parses a string literal which is enclosed in single or double quotes.For literals in double quotes, this parsing mechanism is intended to be as close as possible to the numeric literals supported by the Java programming language itself. Literals in single quotes are completely verbatim, with no escaping performed.
- Parameters:
s
- The string from which the string literal should be parsed.pos
- The offset from which the literal should be parsed. If parsing is successful, the position will be advanced to the next index after the parsed literal.- Returns:
- The parsed string value, unescaped according to Java conventions. Returns null if the string does not begin with a single or double quote.
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parseHex
public static java.lang.Number parseHex(java.lang.CharSequence s, Position pos)
Parses a hexidecimal literal (e.g.,0xfedcba9876543210
).- Parameters:
s
- The string from which the numeric literal should be parsed.pos
- The offset from which the literal should be parsed. If parsing is successful, the position will be advanced to the next index after the parsed literal.- Returns:
- The parsed numeric value—an
Integer
if sufficiently small, or aLong
if needed or if theL
suffix is given; or aBigInteger
if the value is too large even forlong
; ornull
if the string does not begin with the numeric literal telltale of a 0-9 digit with optional minus.
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parseBinary
public static java.lang.Number parseBinary(java.lang.CharSequence s, Position pos)
Parses a binary literal (e.g.,0b010101000011
).- Parameters:
s
- The string from which the numeric literal should be parsed.pos
- The offset from which the literal should be parsed. If parsing is successful, the position will be advanced to the next index after the parsed literal.- Returns:
- The parsed numeric value—an
Integer
if sufficiently small, or aLong
if needed or if theL
suffix is given; or aBigInteger
if the value is too large even forlong
; ornull
if the string does not begin with the numeric literal telltale of a 0-9 digit with optional minus.
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parseOctal
public static java.lang.Number parseOctal(java.lang.CharSequence s, Position pos)
Parses an octal literal (e.g.,01234567
).- Parameters:
s
- The string from which the numeric literal should be parsed.pos
- The offset from which the literal should be parsed. If parsing is successful, the position will be advanced to the next index after the parsed literal.- Returns:
- The parsed numeric value—an
Integer
if sufficiently small, or aLong
if needed or if theL
suffix is given; or aBigInteger
if the value is too large even forlong
; ornull
if the string does not begin with the numeric literal telltale of a 0-9 digit with optional minus.
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parseDecimal
public static java.lang.Number parseDecimal(java.lang.CharSequence s, Position pos)
Parses a decimal literal (e.g.,1234.0987
or1.2e34
).- Parameters:
s
- The string from which the numeric literal should be parsed.pos
- The offset from which the literal should be parsed. If parsing is successful, the position will be advanced to the next index after the parsed literal.- Returns:
- The parsed numeric value, of a type consistent with Java's support
for numeric primitives—or for values outside the normal range
of Java primitives,
BigInteger
orBigDecimal
as appropriate. Returns null if the string does not begin with the numeric literal telltale of a 0-9 digit with optional minus.
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parseNumber
public static java.lang.Number parseNumber(java.lang.CharSequence s, Position pos)
Parses a numeric literal of any known type.This parsing mechanism is intended to be as close as possible to the numeric literals supported by the Java programming language itself.
- Parameters:
s
- The string from which the numeric literal should be parsed.pos
- The offset from which the literal should be parsed. If parsing is successful, the position will be advanced to the next index after the parsed literal.- Returns:
- The parsed numeric value, of a type consistent with Java's support
for numeric primitives—or for values outside the normal range
of Java primitives,
BigInteger
orBigDecimal
as appropriate. Returns null if the string does not begin with the numeric literal telltale of a 0-9 digit with optional minus.
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parseLiteral
public static java.lang.Object parseLiteral(java.lang.CharSequence s, Position pos)
Parses a literal of any known type (booleans, strings and numbers).- Parameters:
s
- The string from which the literal should be parsed.pos
- The offset from which the literal should be parsed. If parsing is successful, the position will be advanced to the next index after the parsed literal.- Returns:
- The parsed value, of a type consistent with Java's support for
literals: either
Boolean
,String
or a concreteNumber
subclass. Returns null if the string does not match the syntax of a known literal. - See Also:
parseBoolean(CharSequence, Position)
,parseString(CharSequence, Position)
,parseNumber(CharSequence, Position)
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