JetBrains/intellij-community · error · SliceFilterParseException

slice.filter.parse.error.incorrect.constant.expected.number

slice.filter.parse.error.incorrect.constant.expected.number

Error message

Incorrect constant (expected number): {0}

What it means

Thrown by JavaSliceProvider.parseFilter when the filter starts with a relational operator (relationType != EQ, i.e. '>', '<', '>=', '<=', '==', '!=' prefixes supported for byte/char/short/int/long types) but the remaining expression evaluates to a non-Number constant. The relational branch builds LongRangeSet constraints and requires the constant to be numeric.

Source

Thrown at java/java-impl/src/com/intellij/slicer/JavaSliceProvider.java:174

    }
    PsiExpression constant;
    try {
      constant = JavaPsiFacade.getElementFactory(expression.getProject()).createExpressionFromText(filter, expression);
    }
    catch (IncorrectOperationException ignore) {
      throw new SliceFilterParseException(JavaBundle.message("slice.filter.parse.error.incorrect.expression", filter));
    }
    PsiType constantType = constant.getType();
    if (constantType == null || !type.isAssignableFrom(constantType)) {
      throw new SliceFilterParseException(JavaBundle.message("slice.filter.parse.error.incorrect.constant.type", type.getPresentableText()));
    }
    Object o = ExpressionUtils.computeConstantExpression(constant);
    if (o == null) {
      throw new SliceFilterParseException(JavaBundle.message("slice.filter.parse.error.expression.must.evaluate.to.constant", filter));
    }
    if (relationType != RelationType.EQ) {
      if (!(o instanceof Number)) {
        throw new SliceFilterParseException(JavaBundle.message("slice.filter.parse.error.incorrect.constant.expected.number", filter));
      }
      if (PsiTypes.longType().equals(type)) {
        LongRangeSet rangeSet = LongRangeSet.point(((Number)o).longValue()).fromRelation(relationType);
        return new JavaValueFilter(DfTypes.longRange(rangeSet));
      }
      LongRangeSet rangeSet = LongRangeSet.point(((Number)o).intValue()).fromRelation(relationType);
      return new JavaValueFilter(DfTypes.intRangeClamped(rangeSet));
    }
    return new JavaValueFilter(DfTypes.constant(o, type));
  }

  private static @Nullable PsiType getType(@NotNull PsiElement expression) {
    if (expression instanceof PsiExpression) {
      return ((PsiExpression)expression).getType();
    }
    else if (expression instanceof PsiVariable) {
      return ((PsiVariable)expression).getType();
    }

View on GitHub (pinned to be881553f2)

Solutions

1. Use an unquoted numeric literal with relational filters, e.g. '>=5' not '>="5"'.
2. Remove the relational prefix if you intend an equality/enum/null filter.
3. Verify the sliced variable is one of byte/char/short/int/long — relational prefixes are only honored for those types anyway.

Example fix

// before:
filter = ">= \"10\""

// after:
filter = ">=10"

if (relationType != RelationType.EQ && !(computed instanceof Number)) {
  // relational filter requires a numeric constant — reject
}

try { provider.parseFilter(expression, filter); } catch (SliceFilterParseException e) { /* relational filters need numbers: re-prompt */ }

When it happens

Trigger: Slicing an int variable and entering '>= "abc"' or '>= true' — the type check passes for some inputs but computeConstantExpression yields a String/Boolean/Character that is not a java.lang.Number.

Common situations: Users adding comparison operators to non-numeric-looking filters; filtering char values where the evaluated constant resolves to something non-numeric; typos like '>="5"' (a quoted string) instead of '>=5'.

Related errors

• slice.filter.parse.error.not.null.filter.not.applicable.for.primitive.type
• slice.filter.parse.error.enum.constant.not.found
• slice.filter.parse.error.incorrect.expression
• slice.filter.parse.error.incorrect.constant.type
• slice.filter.parse.error.expression.must.evaluate.to.constant

AI-assisted analysis of JetBrains/intellij-community@be881553f2 (2026-08-14). Data as JSON: /api/errors/08888086feecb38f. Report an issue: GitHub.