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Errors & Diagnostics

The Bloch interpreter reports errors with 1-based line and column numbers. It exits non-zero on lexical, parse, semantic, or runtime errors.

This page shows typical diagnostics and what they mean.

All errors are displayed in the form

[ERROR]: Stopping program execution...
<ErrorType> error at line:column: error message

Lexical errors​

Reported when the lexer encounters an invalid character or malformed literal.

Parse errors​

Reported when the source does not conform to the grammar.

Semantic errors​

Reported by the semantic analyser for type and rule violations.

Runtime errors​

Thrown during interpretation when executing valid programs that hit invalid states.

Tips​

  • Use small, focused functions and add echo() statements to isolate issues.
  • For multi-shot runs, add --echo=all to see per-shot output alongside tracked summaries.
  • Consult the Semantic Rules for a complete list of compile-time checks.