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Niki Vazou

PROFILE

Niki Vazou

Niki Vazou contributed to the ucsd-progsys/liquidhaskell and liquid-fixpoint repositories, focusing on enhancing type system reliability, numeric reasoning, and cross-solver compatibility. Over six months, she delivered features such as fractional type support, improved set operations for CVC5, and clarified integer type relationships, using Haskell and F# with an emphasis on functional programming and formal verification. Her work included robust bug fixes for type unification and test suite stabilization, as well as code quality improvements through refactoring and formatting. These contributions deepened the projects’ correctness, maintainability, and extensibility, supporting advanced verification and more reliable downstream development.

Overall Statistics

Feature vs Bugs

55%Features

Repository Contributions

42Total
Bugs
10
Commits
42
Features
12
Lines of code
579
Activity Months6

Work History

February 2026

5 Commits • 3 Features

Feb 1, 2026

February 2026 monthly summary focusing on numeric capability expansion in the Liquid Fixpoint ecosystem, reinforced by code quality improvements and strengthened test coverage. Delivered cross-repo fractional support, expanded numerical representations, and added robust division-by-zero tests to improve reliability and maintainability.

October 2025

10 Commits • 5 Features

Oct 1, 2025

October 2025 focused on delivering robust verification capabilities across two core repos, strengthening cross-solver interoperability, and improving type-system reliability and maintainability. Key work spanned CVC5 compatibility enhancements in the fixpoint engine, restoration of essential symbolic interpretations, and strategic cleanup; plus scalable enhancements in Liquid Haskell for set theory, qualifiers, and type representation.

September 2025

1 Commits

Sep 1, 2025

September 2025: Focused on stabilizing and strengthening the Liquid Haskell type checker by clarifying the relationship between primitive integer types and Integer. Implemented a formal assumption and a concrete definition for GHC.Num.Integer.IS, improving the checker's precision on numeric type judgments and reducing ambiguity in integer-related type reasoning. The change was implemented in a focused patch (commit f5bdd642b963f683ff60a5309878a475ce5e043f) and lays groundwork for more robust numeric reasoning in future releases.

June 2025

4 Commits • 2 Features

Jun 1, 2025

June 2025 monthly summary focusing on key accomplishments and business value: Delivered a critical type-unification bug fix for existential types in LiquidHaskell by adjusting ZonkAny handling to align with GHC/LiquidHaskell expectations, upgraded the Fixpoint submodule to a newer commit to maintain compatibility and build stability, and expanded test coverage with a new T753A test data file in liquid-fixpoint-debug. These changes reduce type-checking regressions, improve dependency maintenance, and strengthen verification coverage, enhancing reliability for downstream users and projects relying on Liquid/Haskell tooling.

May 2025

19 Commits • 2 Features

May 1, 2025

Month: 2025-05 – Consolidated progress across two repositories (ucsd-progsys/liquidhaskell and ucsd-progsys/liquid-fixpoint-debug), focusing on robustness of the type system, constructor unification, test stability, and elaboration/casting improvements. The work emphasizes business value through reduced regression surface, more reliable type-checking across GHC versions, and stronger support for complex data structures.

October 2024

3 Commits

Oct 1, 2024

October 2024 monthly summary for ucsd-progsys/liquidhaskell: focused on stabilizing parsing/logic around numeric types and ensuring test suite reliability by correcting test placement. Delivered two high-impact bug fixes that improve correctness of type reasoning and robustness of the test suite, enabling safer changes and faster release cycles.

Activity

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Quality Metrics

Correctness88.0%
Maintainability88.0%
Architecture84.2%
Performance81.4%
AI Usage20.4%

Skills & Technologies

Programming Languages

CabalF#Haskell

Technical Skills

Build System ConfigurationCode FormattingCode QualityCode RefactoringCode StandardizationCompiler DevelopmentCompiler InternalsFormal VerificationFunctional ProgrammingHaskellHaskell programmingLiquid HaskellLogic ProgrammingRefactoringSubmodule Management

Repositories Contributed To

3 repos

Overview of all repositories you've contributed to across your timeline

ucsd-progsys/liquidhaskell

Oct 2024 Feb 2026
6 Months active

Languages Used

CabalHaskell

Technical Skills

Build System ConfigurationCompiler DevelopmentFunctional ProgrammingLogic ProgrammingTestingType Systems

ucsd-progsys/liquid-fixpoint-debug

May 2025 Jun 2025
2 Months active

Languages Used

HaskellF#

Technical Skills

Code RefactoringCode StandardizationCompiler DevelopmentFunctional ProgrammingHaskellRefactoring

ucsd-progsys/liquid-fixpoint

Oct 2025 Feb 2026
2 Months active

Languages Used

Haskell

Technical Skills

Haskellcode cleanupformal verificationfunctional programmingsoftware developmentsymbolic computation