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Add isEquivalentTo method to COSBase and COSObject #712

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fdb96de
Add isEquivalentTo method to COSBase and COSObject
LonelyMidoriya Jul 30, 2026
41cb5af
Update isEquivalentTo logic
LonelyMidoriya Aug 4, 2026
3d16ada
Add check for null
LonelyMidoriya Aug 4, 2026
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43 changes: 43 additions & 0 deletions src/main/java/org/verapdf/cos/COSArray.java
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Original file line number Diff line number Diff line change
Expand Up @@ -189,6 +189,49 @@ private COSObject _at(final int i) {
return this.entries.get(i);
}

@Override
public boolean isEquivalentTo(COSBase o) {
if (this == o) return true;
if (o == null) return false;

if (o.isIndirect()) {
return this.isEquivalentTo(o.getDirectBase());
}

if (!(o instanceof COSArray)) return false;
List<COSBasePair> checkedObjects = new LinkedList<>();
return isEquivalentTo(o, checkedObjects);
}

@Override
boolean isEquivalentTo(COSBase o, List<COSBasePair> checkedObjects) {
if (this == o) return true;
if (o == null) return false;

if (!(o instanceof COSArray)) return false;

COSArray that = (COSArray) o;
if (COSBasePair.listContainsPair(checkedObjects, this, that)) {
return true;
}
COSBasePair.addPairToList(checkedObjects, this, that);

if (!Objects.equals(this.size(), that.size())) return false;

for (int i = 0; i < this.size(); ++i) {
COSBase thisElem = this.at(i).getDirectBase();
COSBase thatElem = that.at(i).getDirectBase();

if (thisElem == null && thatElem == null) continue;
if (thisElem == null || thatElem == null) return false;

if (!thisElem.isEquivalentTo(thatElem, checkedObjects)) {
return false;
}
}
return true;
}

@Override
public boolean equals(Object obj) {
if (this == obj) {
Expand Down
6 changes: 6 additions & 0 deletions src/main/java/org/verapdf/cos/COSBase.java
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Expand Up @@ -140,6 +140,12 @@ public void setObjectKey(COSKey indirectKey) {

public abstract void mark();

public abstract boolean isEquivalentTo(COSBase obj);

boolean isEquivalentTo(COSBase o, List<COSBasePair> checkedObjects) {
return isEquivalentTo(o);
}

boolean equals(Object obj, List<COSBasePair> checkedObjects) {
return this.equals(obj);
}
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17 changes: 17 additions & 0 deletions src/main/java/org/verapdf/cos/COSBoolean.java
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Expand Up @@ -71,6 +71,23 @@ public boolean setBoolean(final boolean value) {
return true;
}

@Override
public boolean isEquivalentTo(COSBase o) {
if (this == o) return true;
if (o == null) return false;

if (o.isIndirect()) {
return isEquivalentTo(o.getDirectBase());
}

if (!(o instanceof COSBoolean)) return false;

COSBoolean that = (COSBoolean) o;

return value == that.value;

}

public boolean get() {
return this.value;
}
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67 changes: 67 additions & 0 deletions src/main/java/org/verapdf/cos/COSDictionary.java
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Expand Up @@ -299,6 +299,73 @@ public Collection<COSObject> getValues() {
return this.entries.values();
}

private Set<ASAtom> getNonNullKeySet() {
Set<ASAtom> nonNullKeys = new HashSet<>();
for (ASAtom key : getKeySet()) {
COSBase value = getKey(key).getDirectBase();
if (value != null) {
nonNullKeys.add(key);
}
}
return nonNullKeys;
}

@Override
public boolean isEquivalentTo(COSBase o) {
if (this == o) return true;
if (o == null) return false;

if (o.isIndirect()) {
return isEquivalentTo(o.getDirectBase());
}

if (!(o instanceof COSDictionary)) return false;

List<COSBasePair> checkedObjects = new LinkedList<>();
return isEquivalentTo(o, checkedObjects);
}

/**
* Internal recursive comparison with cycle detection.
*/
boolean isEquivalentTo(COSBase o, List<COSBasePair> checkedObjects) {
if (this == o) return true;
if (o == null) return false;
if (!(o instanceof COSDictionary)) return false;
Comment thread
LonelyMidoriya marked this conversation as resolved.

COSDictionary that = (COSDictionary) o;

if (COSBasePair.listContainsPair(checkedObjects, this, that)) {
return true;
}
COSBasePair.addPairToList(checkedObjects, this, that);

Set<ASAtom> thisKeys = this.getNonNullKeySet();
Set<ASAtom> thatKeys = that.getNonNullKeySet();

if (!thisKeys.equals(thatKeys)) {
return false;
}

return isEquivalentKeys(that, thisKeys, checkedObjects);
}

protected boolean isEquivalentKeys(COSDictionary that, Set<ASAtom> thisKeys, List<COSBasePair> checkedObjects) {
for (ASAtom key : thisKeys) {
COSBase thisVal = this.getKey(key).getDirectBase();
COSBase thatVal = that.getKey(key).getDirectBase();

if (thisVal == null && thatVal == null) continue;
if (thisVal == null || thatVal == null) return false;

if (!thisVal.isEquivalentTo(thatVal, checkedObjects)) {
return false;
}
}

return true;
}

@Override
public boolean equals(Object obj) {
if (this == obj) {
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11 changes: 11 additions & 0 deletions src/main/java/org/verapdf/cos/COSIndirect.java
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Expand Up @@ -480,6 +480,17 @@ public void mark() {
}
}

@Override
public boolean isEquivalentTo(COSBase o) {
if (this == o) return true;

COSBase thisBase = this.getDirectBase();
if (thisBase == null && o == null) return true;
if (thisBase == null || o == null) return false;

return thisBase.isEquivalentTo(o.getDirectBase());
}

@Override
public boolean equals(Object o) {
if (this == o) return true;
Expand Down
28 changes: 28 additions & 0 deletions src/main/java/org/verapdf/cos/COSInteger.java
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Expand Up @@ -23,6 +23,8 @@
import org.verapdf.cos.visitor.ICOSVisitor;
import org.verapdf.cos.visitor.IVisitor;

import java.math.BigDecimal;

/**
* @author Timur Kamalov
*/
Expand Down Expand Up @@ -75,6 +77,27 @@ public boolean setReal(final double value) {
return true;
}

@Override
public boolean isEquivalentTo(COSBase o) {
if (this == o) return true;
if (o == null) return false;

if (o.isIndirect()) {
return isEquivalentTo(o.getDirectBase());
Comment thread
coderabbitai[bot] marked this conversation as resolved.
}

if (o instanceof COSInteger) {
return this.value == ((COSInteger) o).value;
}

if (o instanceof COSReal) {
COSReal thatReal = (COSReal) o;
return BigDecimal.valueOf(this.value).compareTo(thatReal.getDecimalValue()) == 0;
}

return false;
}

public long get() {
return this.value;
}
Expand All @@ -97,4 +120,9 @@ public boolean equals(Object o) {
return value == that.value;

}

@Override
public BigDecimal getDecimalValue() {
return BigDecimal.valueOf(value);
}
}
17 changes: 17 additions & 0 deletions src/main/java/org/verapdf/cos/COSName.java
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Expand Up @@ -25,6 +25,7 @@
import org.verapdf.cos.visitor.IVisitor;

import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Objects;

/**
Expand Down Expand Up @@ -91,6 +92,22 @@ public boolean setName(final ASAtom value) {
return true;
}

@Override
public boolean isEquivalentTo(COSBase o) {
if (this == o) return true;
if (o == null) return false;

if (o.isIndirect()) {
return isEquivalentTo(o.getDirectBase());
}

if (!(o instanceof COSName)) return false;

COSName that = (COSName) o;

return Objects.equals(value, that.value);
}

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public ASAtom get() {
return value;
}
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5 changes: 5 additions & 0 deletions src/main/java/org/verapdf/cos/COSNull.java
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Expand Up @@ -51,6 +51,11 @@ public Object accept(final ICOSVisitor visitor) {
return visitor.visitFromNull(this);
}

@Override
public boolean isEquivalentTo(COSBase o) {
return equals(o);
}

@Override
public boolean equals(Object o) {
if (this == o) return true;
Expand Down
4 changes: 4 additions & 0 deletions src/main/java/org/verapdf/cos/COSNumber.java
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Expand Up @@ -20,6 +20,8 @@
*/
package org.verapdf.cos;

import java.math.BigDecimal;

/**
* @author Timur Kamalov
*/
Expand All @@ -29,4 +31,6 @@ public COSNumber() {
super();
}

public abstract BigDecimal getDecimalValue();

}
12 changes: 12 additions & 0 deletions src/main/java/org/verapdf/cos/COSObject.java
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Expand Up @@ -494,6 +494,18 @@ public void setIsHeaderFormatComplyPDFA(Boolean isHeaderFormatComplyPDFA) {
this.isHeaderFormatComplyPDFA = isHeaderFormatComplyPDFA;
}

public boolean isEquivalentTo(COSObject o) {
if (o == this) return true;
if (o == null) return false;

COSBase thisBase = this.getDirectBase();
COSBase otherBase = o.getDirectBase();
if (thisBase == null && otherBase == null) return true;
if (thisBase == null || otherBase == null) return false;

return thisBase.isEquivalentTo(otherBase);
}

@Override
public boolean equals(Object o) {
if (this == o) return true;
Expand Down
27 changes: 27 additions & 0 deletions src/main/java/org/verapdf/cos/COSReal.java
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Expand Up @@ -23,6 +23,7 @@
import org.verapdf.cos.visitor.ICOSVisitor;
import org.verapdf.cos.visitor.IVisitor;

import java.math.BigDecimal;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;

Expand All @@ -45,6 +46,11 @@ public class COSReal extends COSNumber {
protected COSReal() {
}

@Override
public BigDecimal getDecimalValue() {
return BigDecimal.valueOf(value);
}
Comment on lines +49 to +52

@coderabbitai coderabbitai Bot Jul 30, 2026

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🩺 Stability & Availability | 🟠 Major | ⚡ Quick win

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
set -euo pipefail

printf 'Files:\n'
fd -a 'COSReal.java|COSInteger.java' .

printf '\nCOSReal outline:\n'
ast-grep outline src/main/java/org/verapdf/cos/COSReal.java || true

printf '\nCOSInteger outline:\n'
ast-grep outline src/main/java/org/verapdf/cos/COSInteger.java || true

printf '\nRelevant code snippets:\n'
sed -n '1,140p' src/main/java/org/verapdf/cos/COSReal.java
printf '\n---\n'
sed -n '1,125p' src/main/java/org/verapdf/cos/COSInteger.java

printf '\nSearch for COSReal/COSInteger creation and getDecimalValue usage:\n'
rg -n "new COSReal|COSReal\.|getDecimalValue|compareTo.*getDecimalValue" src/main/java/org/verapdf/cos src/main/java -g '*.java' | head -200

printf '\nJava BigDecimal.valueOf behavior probe:\n'
python3 - <<'PY'
import math
values = [float('nan'), float('inf'), float('-inf'), 42.0]
for v in values:
    try:
        print(f"{v}: finite={math.isfinite(v)}")
        print(f"  Double.toString={float_repr(v)}")
    except NameError as e:
        print(f"{v}: finite={math.isfinite(v)}")
PY
printf '\nBehavior note: BigDecimal.valueOf(float/double) rejects NaN/infinity via Double.toString.\n'

Repository: veraPDF/veraPDF-parser

Length of output: 14662

🏁 Script executed:

#!/bin/bash
set -euo pipefail

provider=$(mvn help:evaluate -Dexpression=project.properties.pdfbox-provider -q -DforceStdout 2>/dev/null || true)
if [ -n "$provider" ]; then
    echo "current pdfbox-provider=${provider}"
else
    echo "pdfbox-provider not available"
fi

# Read the parser/token code around real-number construction without running repo code.
printf '\nPDFStreamParser token.real context:\n'
sed -n '120,190p' src/main/java/org/verapdf/parser/PDFStreamParser.java

printf '\nPostscript operators around division/log/sqrt context:\n'
sed -n '360,505p' src/main/java/org/verapdf/parser/postscript/PSOperator.java

printf '\nPDFStreamParser number token pattern references:\n'
rg -n "real|NUMBER|Double\\.|parseFloat" src/main/java/org/verapdf/parser src/main/java/org/verapdf/pd/function src/main/java/org/verapdf/pd/colors -g '*.java' | head -120

Repository: veraPDF/veraPDF-parser

Length of output: 11491

🌐 Web query:

Java BigDecimal.valueOf double NaN Infinity IllegalArgumentException source Double.toString

💡 Result:

In Java, the BigDecimal.valueOf(double) method explicitly throws a NumberFormatException (not an IllegalArgumentException) when the provided double is NaN (Not-a-Number), Double.POSITIVE_INFINITY, or Double.NEGATIVE_INFINITY [1][2][3][4]. The rationale for this behavior and its relationship to Double.toString(double) is as follows: 1. Method Behavior: The BigDecimal.valueOf(double) method is designed to be equivalent to calling new BigDecimal(Double.toString(val)) [1][4][5]. Since Double.toString() returns the strings "NaN", "Infinity", or "-Infinity" for non-finite values, and the BigDecimal(String) constructor cannot parse these specific strings into a numeric value, a NumberFormatException is thrown [1][3][6]. 2. Explicit Validation: Historically, this exception was a consequence of passing those strings to the BigDecimal(String) constructor [5]. However, modern implementations of BigDecimal.valueOf(double) (such as in recent OpenJDK versions) include explicit checks—such as !Double.isFinite(val)—to throw a NumberFormatException with a descriptive message ("Infinite or NaN") before any string conversion takes place [6]. 3. API Distinction: This behavior aligns with the standard design of BigDecimal as a class representing finite, arbitrary-precision signed decimal numbers, which inherently does not support non-finite floating-point concepts [2].

Citations:

Prevent finite-only real values from being exposed through BigDecimal conversion.

COSReal.setValue(double) also accepts NaN/infinity via set(), so getDecimalValue() will throw NumberFormatException when called from equivalent-comparison paths. Reject non-finite inputs in set / setReal / construct, or handle them explicitly before calling BigDecimal.valueOf(value) in getDecimalValue() and COSInteger.isEquivalentTo(...).

📍 Affects 2 files
  • src/main/java/org/verapdf/cos/COSReal.java#L49-L52 (this comment)
  • src/main/java/org/verapdf/cos/COSInteger.java#L88-L90
🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@src/main/java/org/verapdf/cos/COSReal.java` around lines 49 - 52, Ensure
non-finite values accepted by COSReal.setValue(double) cannot reach BigDecimal
conversion: update COSReal’s set/setReal/construct paths to reject NaN and
infinities, or explicitly handle them in COSReal.getDecimalValue() before
BigDecimal.valueOf(value). Also update COSInteger.isEquivalentTo(...) to handle
non-finite COSReal values without invoking BigDecimal conversion; apply the
changes in src/main/java/org/verapdf/cos/COSReal.java lines 49-52 and
src/main/java/org/verapdf/cos/COSInteger.java lines 88-90.


protected COSReal(final double value) {
this.value = value;
}
Expand Down Expand Up @@ -88,6 +94,27 @@ public boolean setReal(final double value) {
return true;
}

@Override
public boolean isEquivalentTo(COSBase o) {
if (this == o) return true;

if (o.isIndirect()) {
return isEquivalentTo(o.getDirectBase());
}

if (o instanceof COSReal) {
COSReal thatReal = (COSReal) o;
return this.getDecimalValue().compareTo(thatReal.getDecimalValue()) == 0;
}

if (o instanceof COSInteger) {
COSInteger thatInt = (COSInteger) o;
return this.getDecimalValue().compareTo(thatInt.getDecimalValue()) == 0;
}

return false;
}

public double get() {
return this.value;
}
Expand Down
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