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Ext Macros

Ext macros are a related set of functions, macros, or other features which may not be covered by the core CEL spec from the cel-go/ext package.

Encoders​

base64.decode() -> bytes​

Decodes base64-encoded string to bytes.

This function will return an error if the string input is not base64-encoded.

Signatures​

  • base64.decode(<string>) -> <bytes>

Example​

base64.decode('aGVsbG8=')  // return b'hello'
base64.decode('aGVsbG8')   // error

base64.encode() -> string​

Encodes bytes to a base64-encoded string.

Signatures​

  • base64.encode(<bytes>) -> <string>

Example​

base64.encode(b'hello') // return 'aGVsbG8='

Lists​

list.join() -> string​

Returns a new string with the elements of the list concatenated. Optionally, a separator can be specified to insert between elements.

Signatures​

  • <list<string>>.join(<string?>) -> <string>

Example​

['hello', 'mellow'].join()        // returns 'hellomellow'
['hello', 'mellow'].join(' ')     // returns 'hello mellow'
[].join()                         // returns ''
[].join('/')                      // returns ''

list.filter() -> list​

Returns a new list containing elements that satisfy a provided condition.

Signatures​

  • <list<T>>.filter(<function(T) -> bool>) -> <list<T>>

Example​

[1, 2, 3, 4].filter(x => x % 2 == 0)    // returns [2, 4]
['apple', 'pear'].filter(x => x.includes('a')) // returns ['apple']

list.slice() -> list​

Returns a new sub-list using the indexes provided.

Signatures​

  • <list>.slice(<int>, <int>) -> <list>

Example​

[1,2,3,4].slice(1, 3) // return [2, 3]
[1,2,3,4].slice(2, 4) // return [3 ,4]

Strings​

string.indexOf() -> int​

Returns the index of the first occurrence of a substring within the string. The function also accepts an optional position argument to start the search.

Signatures​

  • <string>.indexOf(<string>, <int?>) -> <int>

Example​

'hello mellow'.indexOf('')         // returns 0
'hello mellow'.indexOf('ello')     // returns 1
'hello mellow'.indexOf('jello')    // returns -1
'hello mellow'.indexOf('', 2)      // returns 2
'hello mellow'.indexOf('ello', 2)  // returns 7

string.split() -> list​

Splits a string into a list of substrings using a specified separator. Optionally, a maximum number of splits can be defined.

Signatures​

  • <string>.split(<string?>, <int?>) -> list<string>

Example​

'hello mellow'.split()             // returns ['hello', 'mellow']
'hello mellow'.split(' ', 1)       // returns ['hello']
'hello,mellow,hi'.split(',')       // returns ['hello', 'mellow', 'hi']
'hello,mellow,hi'.split(',', 2)    // returns ['hello', 'mellow']

string.replace() -> string​

Replaces occurrences of a substring with another string. Optionally, limits the number of replacements.

Signatures​

  • <string>.replace(<string>, <string>, <int?>) -> <string>

Example​

'hello mellow'.replace('l', 'L')        // returns 'heLLo meLLo'
'hello mellow'.replace('l', 'L', 2)     // returns 'heLLo mellow'
'hello mellow'.replace('x', 'X')        // returns 'hello mellow' (no changes)