Package org.scijava.parsington

Class Literals

java.lang.Object
org.scijava.parsington.Literals
public final class Literals extends 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

  • Method Details

    • parseBoolean

      public static Boolean parseBoolean(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 or Boolean.FALSE— or null if the string does not begin with a boolean literal.

    • parseString

      public static String parseString(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.

    • parseHex

      public static Number parseHex(CharSequence s)
      Parses a hexidecimal literal. Both hexadecimal integer (e.g., 0xfedcba9876543210) and hexidecimal floating point (e.g., 0xfedcba.98765432p10f) are supported.
      Parameters:
      s - The string from which the numeric literal should be parsed.
      Returns:
      The parsed numeric value. For hexidecimal integers, returns an Integer if sufficiently small; or a Long if needed or if the L suffix is given; or a BigInteger if the value is too large even for long. For hexidecimal floating point, returns a Float if sufficiently small and the F suffix is given; or a Double otherwise (the D suffix is optional).

    • parseBinary

      public static Number parseBinary(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 a Long if needed or if the L suffix is given; or a BigInteger if the value is too large even for long.

    • parseOctal

      public static Number parseOctal(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 a Long if needed or if the L suffix is given; or a BigInteger if the value is too large even for long.

    • parseDecimal

      public static Number parseDecimal(CharSequence s)
      Parses a decimal literal (integer or otherwise; e.g., 1234567890, 1234.0987 or 1.2e34).
      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 or BigDecimal as appropriate. Returns null if the string does not begin with the numeric literal telltale of a 0-9 digit with optional leading sign.

    • parseNumber

      public static Number parseNumber(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 or BigDecimal as appropriate. Returns null if the string does not begin with the numeric literal telltale of a 0-9 digit with optional leading sign.

    • parseLiteral

      public static Object parseLiteral(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 concrete Number subclass. Returns null if the string does not match the syntax of a known literal.
      See Also:

    • parseBoolean

      public static Boolean parseBoolean(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 or Boolean.FALSE— or null if the string does not begin with a boolean literal.

    • parseString

      public static String parseString(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.

    • parseHex

      public static Number parseHex(CharSequence s, Position pos)
      Parses a hexidecimal literal. Both hexadecimal integer (e.g., 0xfedcba9876543210) and hexidecimal floating point (e.g., 0xfedcba.98765432p10f) are supported.
      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. For hexidecimal integers, returns an Integer if sufficiently small; or a Long if needed or if the L suffix is given; or a BigInteger if the value is too large even for long. For hexidecimal floating point, returns a Float if sufficiently small and the F suffix is given; or a Double otherwise (the D suffix is optional). In either case, returns null if the string does not begin with the numeric literal telltale of a 0-9 digit with optional leading sign.

    • parseBinary

      public static Number parseBinary(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 a Long if needed or if the L suffix is given; or a BigInteger if the value is too large even for long; or null if the string does not begin with the numeric literal telltale of a 0-9 digit with optional leading sign.

    • parseOctal

      public static Number parseOctal(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 a Long if needed or if the L suffix is given; or a BigInteger if the value is too large even for long; or null if the string does not begin with the numeric literal telltale of a 0-9 digit with optional leading sign.

    • parseDecimal

      public static Number parseDecimal(CharSequence s, Position pos)
      Parses a decimal literal (e.g., 1234.0987 or 1.2e34).
      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 or BigDecimal as appropriate. Returns null if the string does not begin with the numeric literal telltale of a 0-9 digit with optional leading sign.

    • parseNumber

      public static Number parseNumber(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 or BigDecimal as appropriate. Returns null if the string does not begin with the numeric literal telltale of a 0-9 digit with optional leading sign.

    • parseLiteral

      public static Object parseLiteral(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 concrete Number subclass. Returns null if the string does not match the syntax of a known literal.
      See Also: