Regular expression patterns for numbers

Regular expression patterns for numbers

Usage

number_patterns

Format

An object of class list of length 9.

Details

• naturalpositive integers without a sign

• nonnegative_integer_no_signonly digits

• integeran optional +- at the beginning followed by only digits (note that "-0" is valid)

• float_no_signdigits, a decimal point, and more digits

• float_or_integer_relaxedan optional +- followed by one of the following:

  • digits

  • digits then a decimal point

  • a decimal point then digits

  • digits then a decimal point then digits

• float_or_integer_strictan optional +- followed by digits optionally followed by a decimal point and digits (starting or ending with a decimal point is not allowed).

• scientific_notationStrict scientific notation made of the following, in order:

  • an optional +-

  • a coefficient that is zero (with an optional decimal point and optional additinoal zeros), a natural number, or a float that does not start with zero

  • one of "e", "E", "d", or "D"

  • a optional +-

  • integer

• scientific_notation_relaxedRelaxed scientific notation (relaxing on the coefficient rules) made of the following, in order:

  • float_or_integer_relaxed

  • one of "e", "E", "d", or "D"

  • a optional +-

  • integer

• number_relaxedAny number format above (based on scientific_notation_relaxed with the exponent as an optional component

Examples

grepl(pattern=number_patterns$scientific_notation_relaxed, "1e5")
#> [1] TRUE
grepl(pattern=number_patterns$scientific_notation_relaxed, "1e-5")
#> [1] TRUE
grepl(pattern=number_patterns$scientific_notation_relaxed, "1e.5")
#> [1] FALSE