Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

@"
"
gmi

Test String

Code Generator

Generated Code

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r"(?mi)\bfield\b\(.*\)\s*\n*\{[^\}]*\s+FieldClass = FlowField;[^\}]*\} ").unwrap(); let string = "table 9070 \"Accounting Services Cue\" { Caption = 'Accounting Services Cue'; fields { field(1; \"Primary Key\"; Code[10]) { Caption = 'Primary Key'; } field(2; \"Requests to Approve\"; Integer) { CalcFormula = Count (\"Approval Entry\" WHERE (Status = CONST (Open), \"Approver ID\" = CONST ('USERID'))); Caption = 'Requests to Approve'; Editable = false; FieldClass = FlowField; } field(4; \"Ongoing Sales Invoices\"; Integer) { CalcFormula = Count (\"Sales Header\" WHERE (\"Document Type\" = FILTER (Invoice))); Caption = 'Ongoing Sales Invoices'; FieldClass = FlowField; } field(5; \"My Incoming Documents\"; Integer) { CalcFormula = Count (\"Incoming Document\"); Caption = 'My Incoming Documents'; FieldClass = FlowField; } field(20; \"User ID Filter\"; Code[50]) { Caption = 'User ID Filter'; FieldClass = FlowFilter; } } keys { key(Key1; \"Primary Key\") { Clustered = true; } } fieldgroups { } } "; // result will be an iterator over tuples containing the start and end indices for each match in the string let result = regex.captures_iter(string); for mat in result { println!("{:?}", mat); } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Rust, please visit: https://docs.rs/regex/latest/regex/