Documentation

String Functions ​

find Requires WDL v1.2 ​

Given two String parameters input and pattern, searches for the occurrence of pattern within input and returns the first match or None if there are no matches. pattern is a regular expression and is evaluated as a POSIX Extended Regular Expression (ERE).

Note that regular expressions are written using regular WDL strings, so backslash characters need to be double-escaped. For example:

wdl
String? first_match = find("hello\tBob", "\\t")

Signatures

wdl
String? find(String, String)

Parameters

  1. String: the input string to search.
  2. String: the pattern to search for.

Returns

  1. The contents of the first match, or None if pattern does not match input.

Example

wdl
String? match = find("Hello, world!", "e..o");
# `match` now contains `ello`.

matches Requires WDL v1.2 ​

Given two String parameters input and pattern, tests whether pattern matches input at least once. pattern is a regular expression and is evaluated as a POSIX Extended Regular Expression (ERE).

To test whether pattern matches the entire input, make sure to begin and end the pattern with anchors. For example:

wdl
Boolean full_match = matches("abc123", "^a.+3$")

Note that regular expressions are written using regular WDL strings, so backslash characters need to be double-escaped. For example:

wdl
Boolean has_tab = matches("hello\tBob", "\\t")

Signatures

wdl
Boolean matches(String, String)

Parameters

  1. String: the input string to search.
  2. String: the pattern to search for.

Returns

  1. true if pattern matches input at least once, otherwise false.

Example

wdl
Boolean matches = matches("sample1234_R1.fastq", "_R1");
# `matches` now contains `true`.

sub ​

Given three String parameters input, pattern, replace, this function replaces all non-overlapping occurrences of pattern in input by replace. pattern is a regular expression and is evaluated as a POSIX Extended Regular Expression (ERE). Regular expressions are written using regular WDL strings, so backslash characters need to be double-escaped (e.g., "\\t").

Signatures

wdl
String sub(String, String, String)

Parameters

  1. String: the input string.
  2. String: the pattern to search for.
  3. String: the replacement string.

Returns

  1. the input string, with all occurrences of the pattern replaced by the replacement string.

Example

wdl
String chocolike = "I like chocolate when\nit's late"
String chocolove = sub(chocolike, "like", "love") #

# `chocolove` now contains `"I love chocolate when\nit's late"`.