feat: for each loops

[zolamk]

Description

Introduces support for forEach loops in reviewpad DSL.

Summary generated by Reviewpad on 31 May 23 10:28 UTC

This pull request contains several changes across the codebase. The env.go and typeinfer.go files have modifications to support built-ins and check for their existence. The engine package has several changes, including new imports, implementations of built-in functions, and modifications to structs and methods to support new features. A new file reviewpad_with_conditional_foreach_workflow.yml has been added, which defines a group and workflow, including a conditional statement. Another new file reviewpad_with_foreach_workflow.yml defines a workflow that iterates over a list of teams and adds a label to each. The lintShadowedVariables() function has been added to handle variable shadowing in workflow runs and workflows. Finally, the inline_rules_normalized.go and exec.go files have changes to support forEach blocks and new package imports.

🤖 Generated by Copilot at eb1dd26

This pull request adds support for forEach clauses in run blocks, using the lang package from reviewpad/v4 to handle list expressions and values. It updates the engine, the linter, and the aladino interpreter to parse, validate, normalize, transform, and execute the forEach clauses. It also adds a Type method to the Value interface and its implementations, and enables type inference and evaluation for list expressions and temporary variables in the aladino language. It modifies several files in the engine and lang/aladino packages, and refactors some test functions in lang/aladino/interpreter_internal_test.go.

Code review and merge strategy

Ask: this pull request requires a code review before merge

How

🤖 Generated by Copilot at eb1dd26

• Import lang package from reviewpad/v4 to use lang.Value interface and other types (link, link, link)
• Add ProcessList and StoreTemporaryVariable methods to Interpreter interface to evaluate and store list expressions and temporary variables in engine environment (link)
• Enable evaluation and type inference for registered values in aladino interpreter, by checking the register map before looking for built-in functions and types (link, link)
• Implement Type method for all value types in aladino interpreter, returning the corresponding type instances (link, link, link, link, link, link, link)
• Add ForEach field to PadWorkflowRunBlock struct, holding a pointer to PadWorkflowRunForEachBlock struct, which has fields for value, in, and do of forEach clause (link)
• Add logic to normalize, transform, and execute forEach clause in run block, by validating the fields, calling normalizeRun and transformRunBlock recursively on do block, and iterating over the list expression and executing the do block for each value (link, link, link, link)
• Add validation for run block to check if it has a forEach clause, and return an error if it has no then block, no actions, no extra actions, and no forEach block (link, link)
• Rename evalGroup function to evalList in aladino interpreter, and update error messages and test functions to use the term list instead of group (link, link, link, link, link, link)
• Loop over the register map of the environment and add the types of the registered values to the built-in types map, to enable type inference for the registered values (link)

[marcelosousa]

@zolamk I need some time to go over these changes. Please bare with me.

[reviewpad]

Pull request is not up to date with the base branch. Reviewpad will rebase it. After the rebase, please trigger Reviewpad by running the command /reviewpad run in a comment.

[marcelosousa]

/reviewpad summarize

[marcelosousa]

Some minor tweaks - the big issue is that we need variable scoping.

The following program will "break":

groups:
  - name: test1
    spec: '["team1", "team2"]'
  - name: test2
    spec: '["team3", "team4"]'


workflows:
  - name: test
    run:
      - forEach:
          value: $teamName
          in: $group("test1")
          do: 
            - forEach:
                value: $teamName
                in: $group("test2")
                do: $addLabel($teamName)
            - $addLabel($teamName)

[reviewpad]

Pull request is not up to date with the base branch. Reviewpad will rebase it. After the rebase, please trigger Reviewpad by running the command /reviewpad run in a comment.

[marcelosousa]

/reviewpad explain

[reviewpad]

This code block is a part of the evaluation and execution of the workflows defined in the configuration file. The specific part you highlighted is responsible for handling the forEach construct within the workflow run block. It iterates over the values specified in the "in" parameter of the forEach construct, creates a new execution scope for the interpreter to prevent any variable shadowing, and then processes the nested statements inside the "do" block of the forEach construct.

The forEach construct allows iterating through lists of values and performing some actions based on each value in that list while keeping the temporary variables within their own execution scope. This code block is responsible for controlling this iteration and maintaining the correct execution scope while going through the list of values and executing the statements in the nested "do" block.

[marcelosousa]

Some comments. For the TODOs, it is okay at this stage to simply open issues for follow-up to not block this PR (up to you to decide).

[reviewpad]

Pull request is not up to date with the base branch. Reviewpad will rebase it. After the rebase, please trigger Reviewpad by running the command /reviewpad run in a comment.

[reviewpad]

Pull request is ready to be merged. Reviewpad will merge it for you.

[zolamk]

We will fix in a separate pull request

• fix type method on function values #922
• add a lint step to ensure built-in functions aren't shadowed by variables #923