Diagnostics and correction

Diagnostic record

A diagnostic carries a stable reason key, severity, typed arguments, a primary span, ordered secondary spans, and an optional edit. Language changes wording only. Technical type names, operators, bounds, and values stay full-width ASCII. Warnings do not block execution. Direct execution maps a diagnostic to source. Built programs contain no source map, but report the trapping function name and relative instruction index. The first example assigns an immutable binding. The correction replaces دع / let with متغير / var and normally returns status 1.

Source span and correction

Select a diagnostic to locate it in the checked source snapshot. Transport spans are half-open UTF-8 byte offsets, and the editor selects logical source. A diagnostic may include a proposed edit. In the immutable-binding example the primary span locates the assigned identifier, secondary spans are empty, and no automatic edit is supplied. Manually replace دع / let with متغير / var. Other diagnostics can include ordered secondary spans. Applying a correction and checking again does not run the program. Corrected source succeeds with status 1 and no output.

For an automatic correction, unsafe print("text") produces unsafe-on-safe-call with a removal edit for the unsafe marker. Apply that edit explicitly, then check again. The primary span locates the marker and the replacement is empty.

fn start_main() -> i64 {
    let value = 0;
    value = 1;
    return value;
}

{
  "browser": {
    "check": "source-error",
    "class": "source-error",
    "output": "",
    "reason": "immutable-assignment"
  },
  "native": {
    "check": 1,
    "status": 1,
    "output": "",
    "reason": "immutable-assignment"
  }
}

fn start_main() -> i64 {
    var value = 0;
    value = 1;
    return value;
}

{
  "browser": {
    "check": "success",
    "class": "success",
    "output": "",
    "processStatus": 1
  },
  "native": {
    "check": 0,
    "status": 1,
    "output": ""
  }
}

Distinct outcomes

The example let byte: u8 = 256 is a checking error because the contextual literal is out of range. In contrast, u8(256) has a valid default i64 operand and traps with invalid-numeric-conversion only if reached. parse_u8("256") returns a failed result with code number-out-of-range. None of these outcomes becomes another.

A source error prevents compilation. A warning permits it. A failed result<T> is a value the program can inspect. A trap stops the whole program and cannot be caught. Load failure precedes execution. limit-stop, cancelled, and host-failure are separate outcomes. success with status 1 is language success, even when a shell treats it as nonzero.

Numeric technical fields

The integer numeric-literal-out-of-range checking diagnostic fields are spelling, type, minimum, maximum. Its floating form has spelling, type, classification, where the classification is finite-overflow. numeric-operator-not-supported has operator, type.

Numeric trap fields are ordered: integer-overflow has type, operation, operand-count, operands; integer-zero-divisor has type, operation, dividend; invalid-shift-count has left-type, count-type, count, width; and invalid-numeric-conversion has source-type, target-type, classification, then source-value or source-bits. Unsigned values through full u64 travel without JavaScript-number rounding.

Release scope and related reading

This page describes ASPL 0.7.0. The linked MVP text is a historical record, not a complete description of current extensions.