#13 - added FoldRev method to collections

[maciej-sz]

Summary by CodeRabbit

• New Features

  • Introduced reverse folding operations across collections, maps, and sequences. This new capability allows users to aggregate data in reverse order for more flexible data processing.

• Refactor

  • Streamlined internal logic by removing obsolete code and standardizing public API documentation, ensuring a more efficient and maintainable experience.

[coderabbitai]

Walkthrough

This pull request introduces reverse folding functionality across various collection types. It updates the forward folding logic in tests (changing the reducer to multiply by 10 and setting an initial value of 100) and adjusts expected outcomes accordingly. New methods named FoldRev have been added to multiple structures (Base, comfyMap, comfyCmpMap, comfySeq, comfyCmpSeq) with corresponding test cases. In addition, the Base interface in the definitions file is updated, and commented-out code is removed from the utility functions.

Changes

File(s)	Change Summary
base_cases_test.go	Updated getFoldCases: reducer now multiplies by 10 with initial value 100 and expected results revised; added new functions getFoldRevCases and testFoldRev for reverse folding tests.
definitions.go, functions.go	definitions.go: Added FoldRev method signature to the Base interface. functions.go: Removed commented-out code and updated the comment header to "Public:".
map.go, mapcmp.go, map_cases_test.go, map_test.go, mapcmp_test.go	Implemented FoldRev for comfyMap and comfyCmpMap (using comfyFoldSliceRev) and modified tests to include scenarios for both forward and reverse fold operations in map collections.
sequence.go, sequencecmp.go, sequence_test.go, sequencecmp_test.go	Introduced FoldRev methods in comfySeq and comfyCmpSeq for reverse folding, with corresponding test cases added to validate the new functionality.

Sequence Diagram(s)

sequenceDiagram
    participant T as Test Function
    participant C as Collection (e.g. comfySeq, comfyMap)
    participant R as comfyFoldSliceRev

    T->>C: Invoke FoldRev(reducer, initial)
    C->>R: Call comfyFoldSliceRev(slice, reducer, initial)
    R-->>C: Return computed reverse fold value
    C-->>T: Return final folded result

Loading

Poem

I'm hopping through my code with glee,
New reverse folds set my variables free.
Multiplying by ten, the numbers align,
Test cases jump in, all crisp and fine.
With whiskers twitching and a joyful beat,
My code runs swift—oh, ain't that neat!
Happy hops to every bug we defeat!

Warning

There were issues while running some tools. Please review the errors and either fix the tool’s configuration or disable the tool if it’s a critical failure.

🔧 golangci-lint (1.62.2)

Error: can't load config: the Go language version (go1.23) used to build golangci-lint is lower than the targeted Go version (1.24)
Failed executing command with error: can't load config: the Go language version (go1.23) used to build golangci-lint is lower than the targeted Go version (1.24)

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📜 Recent review details

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Review profile: CHILL
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📥 Commits

Reviewing files that changed from the base of the PR and between 0531fcb and 2b7d274.

📒 Files selected for processing (12)

• base_cases_test.go (3 hunks)
• definitions.go (1 hunks)
• functions.go (2 hunks)
• map.go (1 hunks)
• map_cases_test.go (3 hunks)
• map_test.go (1 hunks)
• mapcmp.go (2 hunks)
• mapcmp_test.go (1 hunks)
• sequence.go (1 hunks)
• sequence_test.go (1 hunks)
• sequencecmp.go (1 hunks)
• sequencecmp_test.go (1 hunks)

🔇 Additional comments (23)

sequence_test.go (1)

198-200: Code changes look good

The new test function for reverse folding operation is properly implemented, following the convention of other test functions in this file.

mapcmp_test.go (1)

240-242: Implementation looks correct

The test function for FoldRev in comfyCmpMap follows the same pattern as other test functions, maintaining consistency in the test suite.

sequence.go (1)

131-133: Good implementation of FoldRev

The implementation correctly leverages the comfyFoldSliceRev helper function, mirroring the pattern used by the Fold method with comfyFoldSlice. This maintains consistency across the codebase and properly enables reverse folding functionality.

map_test.go (1)

212-214: Test implementation is correct

The test function is properly implemented using the same pattern as the other test functions in this file, specifically calling the testMapFoldRev helper with the appropriate builder.

map.go (1)

129-131: Implementation looks good

The FoldRev method implements reverse folding for the comfyMap structure, correctly delegating to the comfyFoldSliceRev utility function. The method is well-placed after the Fold method which follows consistent code organization.

sequencecmp_test.go (1)

202-204: Test implementation looks good

The test for FoldRev follows the same pattern as other test functions in this file, delegating to the shared test helper function. It's placed in a logical location following the Fold test and maintains consistency with the rest of the test suite.

sequencecmp.go (1)

143-145: Implementation looks good

The FoldRev method for comfyCmpSeq is implemented consistently with other collection types, delegating to the comfyFoldSliceRev utility function. It's well-placed after the Fold method, maintaining good code organization.

definitions.go (1)

61-61: Interface correctly updated

The FoldRev method has been properly added to the Base interface, completing the TODO that was previously in place. The method signature matches the pattern of the existing Fold method, maintaining consistent API design.

functions.go (2)

3-3: Consistent documentation style improvement.

The change from "// public API:" to "// Public:" improves consistency in the codebase documentation style.

---

16-16: Good documentation of potential API improvements.

Documenting the consideration for renaming "MapTo" to "Transform" is valuable for future development. This kind of commentary helps track design decisions and potential API improvements.

mapcmp.go (2)

24-29: Good optimization in the initialization process.

Direct initialization of the comfyCmpMap struct rather than using NewCmpMap() and then casting it eliminates an unnecessary intermediate step, making the code more efficient.

---

148-150: Well-implemented reverse folding functionality.

The FoldRev method is a good complement to the existing Fold method, providing a way to fold a collection in reverse order. The implementation is concise and consistent with the existing folding functionality.

map_cases_test.go (6)

1204-1206: Good use of underscore for unused parameter

Using _ instead of i clearly indicates that the parameter is intentionally unused, which aligns with Go's best practices.

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1211-1221: Good test coverage for empty collection with initial value

This new test case improves test coverage by verifying the behavior of Fold() when an initial value is provided to an empty collection.

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1233-1243: Well-constructed test for one-item collection with initial value

Good addition of a test case that verifies the behavior of Fold() when combining a single collection item with an initial value. This ensures the reducer function properly combines values when an initial value is specified.

---

1258-1270: Comprehensive test for complex folding logic

This test case effectively verifies more complex folding behavior by using a multiplication operation (acc.Val()*10 + current.Val()) rather than simple addition. This provides better coverage of the fold functionality.

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1297-1382: Well-implemented test cases for new FoldRev functionality

The test cases for FoldRev are comprehensive and mirror the structure of the Fold tests, ensuring equivalent test coverage. The expected result for the complex test case (line 1368) correctly differs from the forward fold case, reflecting the reversed traversal order.

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1384-1394: Properly implemented test function for FoldRev

The testMapFoldRev function correctly follows the same pattern as testMapFold, ensuring consistent testing methodology between the two related functions.

base_cases_test.go (5)

769-773: Good update to the reducer function and expected values.

The fold logic has been updated to multiply the accumulator by 10 before adding the current value, which is consistent with the updated expected results. The initial value change from 0 to 100 is correctly reflected in the test expectations.

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795-795: Correct expected value for the updated fold operation.

The expected result has been correctly updated to 113653, which matches the calculation flow:

• Start with 100
• First: 100*10 + 111 = 1111
• Second: 1111*10 + 222 = 11332
• Third: 11332*10 + 333 = 113653

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806-806: Correct expected value for the fold operation with index inclusion.

The expected result has been properly updated to account for the multiplication change in the reducer function.

---

823-870: Well-implemented test cases for the new FoldRev functionality.

The test cases for the reverse fold operation are comprehensive, covering:

• Empty collections (return the initial value)
• Single item collections
• Multi-item collections
• Index inclusion in calculations

The expected results are correctly calculated for a reverse traversal of the collection elements.

---

872-882: Good implementation of the FoldRev test function.

The test function correctly:

1. Gets test cases from getFoldRevCases
2. Iterates through each test case
3. Calls FoldRev with the appropriate parameters
4. Verifies the result against expected values

This follows the same pattern as the other test functions in this file for consistency.

✨ Finishing Touches

• 📝 Generate Docstrings

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Files with missing lines	Coverage Δ
definitions.go	100.00% <ø> (ø)
functions.go	0.00% <ø> (ø)
map.go	100.00% <100.00%> (ø)
mapcmp.go	100.00% <100.00%> (ø)
sequence.go	100.00% <100.00%> (ø)
sequencecmp.go	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

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