Restrictions on Source Programs

The following DrScheme facilities are not handled.

• Primitives for dynamic loading and evaluation: load, load/cd, load-relative, load/use-compiled, current-load, require-library-use-compiled,
  

  compile, eval, current-eval, expand-defmacro and expand-defmacro-once.

• Primitives that dynamically manipulate the top-level environment: undefine, global-defined-value, invoke-open-unit and invoke-open-unit/sig.
• MzScheme's interfaces, exception system and exception hierarchy.
• Primitives that access structures without the appropriate selectors: struct-ref and struct->vector.
• MrSpidey doesn't know about DrScheme language levels.
• Primitive names should not be assigned or defined.

Certain potential errors are not detected:

• Returning an inappropriate number of multiple values to a single value context.
• Index out of bounds on vector, string and list operations.
• compound-unit errors. Since unit's are normally used in a first-order manner, these errors are typically easy to detect using the evaluator.
• The arguments to primitive-name and primitive-result-arity are only checked to be procedures, not primitive procedures.
• Errors in read due to ill-formed s-expression on the input port.

The analysis of certain kinds of code is not completely sound:

• Values passed to exception handlers.
• Tracking values through parameters.
• Tracking values through will executors.
• MrSpidey doesn't translate unit/sig into unit, as MzScheme does.