Regex package:hledger-lib

Easy regular expression helpers, currently based on regex-tdfa. These should:

• be cross-platform, not requiring C libraries
• support unicode
• support extended regular expressions
• support replacement, with backreferences etc.
• support splitting
• have mnemonic names
• have simple monomorphic types
• work with simple strings

Regex strings are automatically compiled into regular expressions the first time they are seen, and these are cached. If you use a huge number of unique regular expressions this might lead to increased memory usage. Several functions have memoised variants (*Memo), which also trade space for time. Currently two APIs are provided:

• The old partial one (with ' suffixes') which will call error on any problem (eg with malformed regexps). This comes from hledger's origin as a command-line tool.
• The new total one which will return an error message. This is better for long-running apps like hledger-web.

Current limitations:

• (?i) and similar are not supported

An error message arising during a regular expression operation. Eg: trying to compile a malformed regular expression, or trying to apply a malformed replacement pattern.

Regular expression. Extended regular expression-ish syntax ? But does not support eg (?i) syntax.

Test whether a Regexp matches a String. This is an alias for matchTest for consistent naming.

Tests whether a Regexp matches a Text. This currently unpacks the Text to a String, to work around a performance bug in regex-tdfa (#9), which may or may not be relevant here.

Return a (possibly empty) list of match groups derived by applying the Regex to a Text.

A memoising version of regexReplace. Caches the result for each search pattern, replacement pattern, target string tuple. This won't generate a regular expression parsing error since that is pre-compiled nowadays, but there can still be a runtime error from the replacement pattern, eg with a backreference referring to a nonexistent match group.

Convert an account name to a regular expression matching it but not its subaccounts.

Convert an account name to a regular expression matching it but not its subaccounts, case insensitively.

Convert an account name to a regular expression matching it and its subaccounts.

Convert an account name to a regular expression matching it and its subaccounts, case insensitively.

Regular expressions matching common English top-level account names, used as a fallback when account types are not declared.