Handle Type Coercion Rules (e.g. int + float = float)

Implicit Conversions at Boundaries

C promotes int to float in mixed arithmetic; Java widens primitives automatically. Clang applies standard conversion rules before checking assignment compatibility. Coercion rules are where subtle bugs hide: silent truncation, sign extension, and unexpected overflow.

Common Coercion Rules

Integer promotion: char and short widen to int. Usual arithmetic conversions: if one operand is float, the other promotes. Assignment may narrow with a warning or error depending on the language.

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• Coercion happens before operator type checking
• Explicit casts bypass or supplement implicit rules
• String + number coercion is language-specific (JavaScript)
• Document which conversions are safe vs lossy

Connecting to real compilers

Production compilers embed this step inside a longer pipeline. GCC flows through cpp, cc1, assembly, and ld; Clang uses the driver, Sema, LLVM IR passes, and a target backend. LLVM bitcode, JVM bytecode, and WASM are other familiar IRs at the same layer. The exercise isolates one pass so you can test it alone before chaining it to the next stage.

Why for this exercise

You will implement type coercion rules for mixed-type arithmetic and assignments. This exercise asks you to promote operand types per language rules and report errors when implicit conversion is not permitted.