Bleach: A Programming Language for Teaching Compilers

• Victor Costa UFPE
• Leopoldo Teixeira UFPE

DOI: https://doi.org/10.5753/sblp.2026.28580

Resumo

Programming languages designed as teaching tools for undergraduate Compilers courses occupy a constrained design space. Existing options such as COOL and MiniJava are deliberately minimal and statically typed, while ChocoPy targets compilation rather than interpretation. This paper presents Bleach, a dynamically typed, object-oriented programming language with a tree-walk interpreter implemented in C++, designed to fill the gap left by these alternatives. Structurally inspired by Lox (from Crafting Interpreters), Bleach extends it with multi-line comments, do-while and for loops, elif clauses, a ternary operator, a list type, break/continue statements, an expanded standard library, and a resolver that statically detects 10 distinct classes of scoping and control-flow errors. We present the language’s design rationale, describe the architecture and key implementation decisions of its interpreter, and compare Bleach feature-by-feature with ChocoPy, COOL, and MiniJava, positioning it in the space of compiler-teaching languages. We validated the interpreter through a 44-case test suite covering all AST node types and by implementing 11 standard algorithms and data structures in the language; all test cases pass, and every algorithm runs correctly without modification to the language. Despite the lack of an empirical pedagogical evaluation, we outline how Bleach could be incorporated into a 15-week undergraduate introductory Compilers course.

Palavras-chave: Teaching, Compilers

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