Class SelfComparisonOrError

java.lang.Object

org.ek9lang.compiler.common.RuleSupport

org.ek9lang.compiler.common.TypedSymbolAccess

org.ek9lang.compiler.phase5.SelfComparisonOrError

All Implemented Interfaces:

Consumer<EK9Parser.ExpressionContext>

final class SelfComparisonOrError
extends TypedSymbolAccess
implements Consumer<EK9Parser.ExpressionContext>

Detects self-comparison expressions where both sides resolve to the same symbol (E08081).

Expressions like value == value (always true), value <> value (always false), or value <=> value (always 0) are pointless and indicate copy-paste errors or logic bugs.

Only comparison operators are flagged. Arithmetic operators like a + a (valid doubling) and logical operators like a and a are not flagged.

Research basis: Microsoft study (2011) found self-comparison bugs in 3% of copy-paste errors. GCC, Clang, and IntelliJ all flag self-comparison as a warning.

Field Summary

Fields inherited from class RuleSupport

errorListener, symbolsAndScopes

Constructor Summary

Constructors

Constructor	Description
SelfComparisonOrError(SymbolsAndScopes symbolsAndScopes, ErrorListener errorListener)

Method Summary

Modifier and Type	Method	Description
void	accept(EK9Parser.ExpressionContext ctx)

Methods inherited from class TypedSymbolAccess

getRecordedAndTypedSymbol, isProcessingScopePure, recordATypedSymbol

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface Consumer

andThen

Constructor Details

SelfComparisonOrError

SelfComparisonOrError(SymbolsAndScopes symbolsAndScopes,
 ErrorListener errorListener)

Method Details

accept

public void accept(EK9Parser.ExpressionContext ctx)

Specified by:

accept in interface Consumer<EK9Parser.ExpressionContext>