Summary

Only string constants (literals) are supported in WASM codegen. There is no dynamic string construction at runtime.

Current state

• String literals are interned in a StringPool and placed in a WASM data segment
• IO.print can print constant strings
• No string_concat, to_string, or other dynamic string operations in codegen
• String operations in contracts are handled by the verifier (Z3), not at runtime

What's needed

• Dynamic string allocation in linear memory
• Runtime implementations of string_concat, to_string, length for strings
• Integration with garbage collection (issue Garbage collection for WASM linear memory #51) for reclaiming string memory

Spec reference

Chapter 11, Section 11.12 "Limitations"