List indexing with variables

[sebastian9]

Describe the Bug

When attempting to index a list using a variable, the expression A[R] does not produce the expected output. Despite R being set to 3 and A being a list with the values ["Yes", "No", "Yes"], the expected output should be the third element of list A twice, as in "Yes". However, the output is[ 3, 3, 3 ].

FEEL Playground Issue

Steps to Reproduce

evaluate('A[R]',{
"R": 3,
"A": ["Yes","No","Yes"]
})

Expected Behavior

The expression returns the value of the list on the index which matches the variable value; ie, "Yes"

Environment

• Host (Browser/Node version), if applicable: Node v21.5.0
• OS: macOS 14.2.1
• Library version: 3.0.0

Additionally, this can be replicated in the playground -> FEEL Playground Issue

[sebastian9]

I'm not crazy:

[sebastian9]

@nikku I'm wondering if there's an ETA on this, we'd like to use FEELIN for our project because it keeps things in javascript land. Would you endorse its use in production?

[nikku]

@sebastian9 I cannot confirm or deny that feelin is ready for production. Like any software it will have bugs. Also, I don't offer "enterprise support" so you'll need to wait a week or two before I pick up pull requests.

Alternatives exists, such as dsntk/feel-evaluator that could be transpiled to WASM and used in browserland, too. It sets the bar high and fully operates "in the spirit of FEEL", including context sensitivity, DMN-TCK compliance and friends. It may not be as approachable to you as a JavaScript engineer.