Functions and Operators

The primary definition for a character match comes from:

• Plain match, ie Plain "A" matches the "A" character, Plain "Hello" matches the word "Hello"
• OneOf match, ie OneOf "AC" matches on "A" and "C"
• Between match, ie Between 'a' 'z' matches all characters between 'a' and 'z'
• Macro, the macro module provides various pre-defined character classes, including wildcard Macro.any

The Plain and OneOf constructions do not require character escaping. So Plain "." matches the dot character. Macro.any is used as wildcard-character.

Character Classes

Both OneOf and Between define character classes. Of wich also exist an inversion NotOneOf and NotBetween.

Character classes can be subtracted.

For example: Between 'a' 'z' - OneOf "klm" // matches all lowercase leters except "klm"

Operators

All Regular Expression (sub-)patterns can be used for these operators:

• + - concatenation, ie Plain "A" + Plain "B" (which is the same as Plain "AB");
• ||| - or, either the left or right side must match, ie Plain "AB" ||| OneOf "CD" matches: "AB", "C", "D";

Repetitions

One can use one of these repetitions:

• ZeroOrMore - the input sub-pattern may repeat zero or more times;
• OnceOrMore - the input sub-pattern may repeat once or more times;
• RepeatRange - the input sub-pattern may repeat between a min and max times;
• RepeatExact - the input sub-pattern must repeat exactly the indicated times;
• Optional - Zero or one;

Grouping

These ways are supported for groups:

• Group - Anonymous groups
• NamedGroup - NamedGroup

Usually, anonymous groups are useful in lesser complex patterns. The named groups help in complex patterns. Naming groups make it a lot easier to extract sub-strings from a matching result.

Conversion

The conversion module is used to create the pattern-string:

• ToStringStartPattern - Creates the pattern from the input, the start of the input string must match the start of the pattern;
• ToFullstringPattern - Creates the pattern from the input, the full string must match the full pattern;
• ToPattern - Creates the pattern from the input, the pattern-matching can start in the middle of the input string, and may match a substring;

The conversion module glues it together:

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open ReggerIt
open System.Text.RegularExpressions

let pattern = Plain "HelloWorld" |> Convert.ToStringStartPattern

let input = "HelloWorld"

Regex.Match(input, pattern) // match success

Macro

The Macro module contains various frequently used character classes and definitions:

• Macro.any - wildcard character, matches anything except newline
• Macro.whitespace - matches any whitespace, including space, tab, and more
• Macro.nonWhitespace - matches any non whitespace
• Macro.bell - matches the bell character
• Macro.backspace - matches the bachspace character
• Macro.tab - matches the tab character
• Macro.carriageReturn - matches the carriageReturn character
• Macro.verticalTab - matches the verticalTab character
• Macro.formFeed - matches the formFeed character
• Macro.newLine - matches the newLine character
• Macro.escape - matches the escape character
• Macro.ascii - matches the specified 8-bit hex character
• Macro.utf16 - matches the specified 16-bit hex character
• Macro.wordCharacter - matches a word character, letters, digits
• Macro.nonWordCharacter - matches a non-word character
• Macro.decimalDigit - matches a decimal digit character 0..9
• Macro.nonDecimalDigit - matches a non-decimal digit character 0..9
• Macro.namedBlock - matches a character from the specified named block