regex101: Powershell function declaration

Definition Group(?(DEFINE) (?<varchar> [[:alnum:]] | [-_] ) (?<funcname> [[:alpha:]](?&varchar)* ) (?<varname> \$(?&funcname) ) (?<typepart> [[:alpha:][[:alnum:]]*) (?<typename> \[ (?&typepart) ( \.(?&typepart) )* \] ) (?<arg> (?&typename)? \s* (?&varname) ) (?<arglist> (?&arg) ( \s*,\s* (?&arg) )* ) (?<args> ( $ (?&arglist)? $ )? ) (?<func_decl> ^ \s* function \s+ (?&funcname) \s* (?&args) \s* \{ ) )

Group varchar(?<varchar> [[:alnum:]] | [-_] )

1st Alternative [[:alnum:]]

Character Class[[:alnum:]]

[:alnum:]an alphanumeric character [a-zA-Z0-9]

2nd Alternative [-_]

Character Class[-_]

-the literal - (45₁₀ / 55₈ / 2D₁₆)

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Group funcname(?<funcname> [[:alpha:]](?&varchar)* )

Character Class[[:alpha:]]

[:alpha:]an alphabetic character [a-zA-Z]

(?&varchar)*calls group varchar as a subroutine, repeated any number of times

Group varname(?<varname> \$(?&funcname) )

\$the literal $ (36₁₀ / 44₈ / 24₁₆)

(?&funcname)calls group funcname as a subroutine

Group typepart(?<typepart> [[:alpha:][[:alnum:]]*)

Character Class[[:alpha:][[:alnum:]]*

*matches any number of characters from the set below:

[:alpha:]an alphabetic character [a-zA-Z]

[the literal [ (91₁₀ / 133₈ / 5B₁₆)

[:alnum:]an alphanumeric character [a-zA-Z0-9]

Group typename(?<typename> \[ (?&typepart) ( \.(?&typepart) )* \] )

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

(?&typepart)calls group typepart as a subroutine

Group 6( \.(?&typepart) )*

*repeats the group contents below any number of times:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

(?&typepart)calls group typepart as a subroutine

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

Group arg(?<arg> (?&typename)? \s* (?&varname) )

(?&typename)?optionally calls group typename as a subroutine

\s*any whitespace character, repeated any number of times

(?&varname)calls group varname as a subroutine

Group arglist(?<arglist> (?&arg) ( \s*,\s* (?&arg) )* )

(?&arg)calls group arg as a subroutine

Group 9( \s*,\s* (?&arg) )*

*repeats the group contents below any number of times:

\s*any whitespace character, repeated any number of times

,the literal , (44₁₀ / 54₈ / 2C₁₆)

\s*any whitespace character, repeated any number of times

(?&arg)calls group arg as a subroutine

Group args(?<args> ( $ (?&arglist)? $ )? )

Group 11( $ (?&arglist)? $ )?

?repeats the group contents below at most once:

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

(?&arglist)?optionally calls group arglist as a subroutine

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

Group func_decl(?<func_decl> ^ \s* function \s+ (?&funcname) \s* (?&args) \s* \{ )

^start of line

\s*any whitespace character, repeated any number of times

function the literal text function (case sensitive)

\s+any whitespace character, repeated at least once

(?&funcname)calls group funcname as a subroutine

\s*any whitespace character, repeated any number of times

(?&args)calls group args as a subroutine

\s*any whitespace character, repeated any number of times

\{the literal { (123₁₀ / 173₈ / 7B₁₆)

(?&func_decl)calls group func_decl as a subroutine

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Search reference

Regular Expression

(?(DEFINE)  
  (?<varchar> [[:alnum:]] | [-_] )
  (?<funcname> [[:alpha:]](?&varchar)* )
  (?<varname> \$(?&funcname) )
  (?<typepart> [[:alpha:][[:alnum:]]*)
  (?<typename> \[ (?&typepart) ( \.(?&typepart) )* \] )
  (?<arg> (?&typename)? \s* (?&varname) ) 
  (?<arglist> (?&arg) ( \s*,\s* (?&arg) )* )
  (?<args> ( \( (?&arglist)? \) )? )
  (?<func_decl> ^ \s* function \s+ (?&funcname) \s* (?&args) \s* \{ )
) 
(?&func_decl)

Test String
New

function Main ($x, [string]$y) {
 function Get-Content {
 function main_- () { 
function main([string.Array] $mfd_) {

Regular Expressions 101

Regular Expression

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Regular Expression

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