CE SQL v1 (#641)

- add exception factory for cesql exceptions
- extend EvaluationResult to be usable internally
- expressions use results instead of a thrower interface
- functions use results instead of a thrower interface
- parser handles not equals correctly, does not eagerly evaluate when there may be an error
- parser handles integer literals properly
- updated test files to test v1 spec

Signed-off-by: Calum Murray <[email protected]>
Co-authored-by: Pierangelo Di Pilato <[email protected]>

pom.xml

@@ -169,7 +169,6 @@
                         <link>https://docs.spring.io/spring-framework/docs/current/javadoc-api/</link>
                         <link>https://jakarta.ee/specifications/platform/8/apidocs/</link>
                         <link>https://kafka.apache.org/30/javadoc/</link>
-                        <link>https://qpid.apache.org/releases/qpid-proton-j-0.33.7/api/</link>
                         <link>https://fasterxml.github.io/jackson-databind/javadoc/2.10/</link>
                     </links>
                     <source>8</source>

sql/src/main/antlr4/imports/CESQLLexer.g4

@@ -70,7 +70,7 @@ FALSE: 'FALSE';
 
 DQUOTED_STRING_LITERAL:                      DQUOTA_STRING;
 SQUOTED_STRING_LITERAL:                      SQUOTA_STRING;
-INTEGER_LITERAL:                             INT_DIGIT+;
+INTEGER_LITERAL:                             ('+' | '-')? INT_DIGIT+;
 
 // Identifiers
 

sql/src/main/java/io/cloudevents/sql/EvaluationContext.java

@@ -18,19 +18,5 @@ public interface EvaluationContext {
      */
     String expressionText();
 
-    /**
-     * Append a new exception to the evaluation context.
-     * This exception will be propagated back in the evaluation result.
-     *
-     * @param exception exception to append
-     */
-    void appendException(EvaluationException exception);
-
-    /**
-     * Append a new exception to the evaluation context.
-     * This exception will be propagated back in the evaluation result.
-     *
-     * @param exceptionFactory exception factory, which will automatically include expression interval and text
-     */
-    void appendException(EvaluationException.EvaluationExceptionFactory exceptionFactory);
+    ExceptionFactory exceptionFactory();
 }

sql/src/main/java/io/cloudevents/sql/EvaluationException.java

@@ -20,23 +20,27 @@ public enum ErrorKind {
         /**
          * An implicit or an explicit casting failed.
          */
-        INVALID_CAST,
+        CAST,
         /**
          * An event attribute was addressed, but missing.
          */
         MISSING_ATTRIBUTE,
         /**
          * Error happened while dispatching a function invocation. Reasons may be invalid function name or invalid arguments number.
          */
-        FUNCTION_DISPATCH,
+        MISSING_FUNCTION,
         /**
          * Error happened while executing a function. This usually contains a non null cause.
          */
-        FUNCTION_EXECUTION,
+        FUNCTION_EVALUATION,
         /**
          * Error happened while executing a math operation. Reason may be a division by zero.
          */
-        MATH
+        MATH,
+        /**
+         * Any error that does not fall into the other error kinds
+         */
+        GENERIC,
     }
 
     private final ErrorKind errorKind;

sql/src/main/java/io/cloudevents/sql/EvaluationRuntime.java

@@ -7,35 +7,6 @@
  * The evaluation runtime takes care of the function resolution, casting and other core functionalities to execute an expression.
  */
 public interface EvaluationRuntime {
-
-    /**
-     * Check if the cast can be executed from {@code value} to the {@code target} type.
-     *
-     * @param value  the value to cast
-     * @param target the type cast target
-     * @return false if the cast trigger an error, true otherwise.
-     */
-    boolean canCast(Object value, Type target);
-
-    /**
-     * Return the {@code value} casted to the {@code target} type.
-     *
-     * @param ctx    the evaluation context
-     * @param value  the value to cast
-     * @param target the type cast target
-     * @return the casted value, if the cast succeeds, otherwise the default value of the target type
-     */
-    Object cast(EvaluationContext ctx, Object value, Type target);
-
-    /**
-     * Return the {@code value} casted to the {@code target} type. If fails, this is going to throw an exception without the evaluation context.
-     *
-     * @param value  the value to cast
-     * @param target the type cast target
-     * @return the casted value, if the cast succeeds, otherwise the default value of the target type
-     */
-    Object cast(Object value, Type target) throws EvaluationException;
-
     /**
      * Resolve a {@link Function} starting from its name and the concrete number of arguments.
      *

sql/src/main/java/io/cloudevents/sql/ExceptionFactory.java

@@ -0,0 +1,51 @@
+package io.cloudevents.sql;
+
+import org.antlr.v4.runtime.RecognitionException;
+import org.antlr.v4.runtime.misc.Interval;
+import org.antlr.v4.runtime.tree.ParseTree;
+
+public interface ExceptionFactory {
+    EvaluationException.EvaluationExceptionFactory invalidCastTarget(Class<?> from, Class<?> to);
+
+    EvaluationException.EvaluationExceptionFactory castError(Class<?> from, Class<?> to, Throwable cause);
+
+    EvaluationException missingAttribute(Interval interval, String expression, String key);
+
+    EvaluationException cannotDispatchFunction(Interval interval, String expression, String functionName, Throwable cause);
+
+    EvaluationException.EvaluationExceptionFactory functionExecutionError(String functionName, Throwable cause);
+
+    EvaluationException divisionByZero(Interval interval, String expression, Integer dividend);
+
+    EvaluationException mathError(Interval interval, String expression, String errorMessage);
+
+    static ParseException cannotParseValue(ParseTree node, Type target, Throwable cause) {
+        return new ParseException(
+            ParseException.ErrorKind.PARSE_VALUE,
+            node.getSourceInterval(),
+            node.getText(),
+            "Cannot parse to " + target.name() + ": " + cause.getMessage(),
+            cause
+        );
+    }
+
+    static ParseException recognitionError(RecognitionException e, String msg) {
+        return new ParseException(
+            ParseException.ErrorKind.RECOGNITION,
+            new Interval(e.getOffendingToken().getStartIndex(), e.getOffendingToken().getStopIndex()),
+            e.getOffendingToken().getText(),
+            "Cannot parse: " + msg,
+            e
+        );
+    }
+
+    static ParseException cannotEvaluateConstantExpression(EvaluationException exception) {
+        return new ParseException(
+            ParseException.ErrorKind.CONSTANT_EXPRESSION_EVALUATION,
+            exception.getExpressionInterval(),
+            exception.getExpressionText(),
+            "Cannot evaluate the constant expression: " + exception.getExpressionText(),
+            exception
+        );
+    }
+}

sql/src/main/java/io/cloudevents/sql/Function.java

@@ -1,6 +1,7 @@
 package io.cloudevents.sql;
 
 import io.cloudevents.CloudEvent;
+import io.cloudevents.sql.impl.runtime.EvaluationResult;
 
 import java.util.List;
 
@@ -15,9 +16,9 @@ public interface Function extends FunctionSignature {
      * @param ctx               the evaluation context
      * @param evaluationRuntime the evaluation runtime
      * @param event             the expression input event
-     * @param arguments         the arguments passed to this function. Note: the arguments are already casted to the appropriate type declared in the signature
+     * @param arguments         the arguments passed to this function. Note: the arguments are already cast to the appropriate type declared in the signature
      * @return the return value of the function
      */
-    Object invoke(EvaluationContext ctx, EvaluationRuntime evaluationRuntime, CloudEvent event, List<Object> arguments);
+    EvaluationResult invoke(EvaluationContext ctx, EvaluationRuntime evaluationRuntime, CloudEvent event, List<Object> arguments);
 
 }

sql/src/main/java/io/cloudevents/sql/FunctionSignature.java

@@ -18,6 +18,11 @@ public interface FunctionSignature {
      */
     Type typeOfParameter(int i) throws IllegalArgumentException;
 
+    /**
+     * @return function return type
+     */
+    Type returnType();
+
     /**
      * @return the arity, excluding the vararg parameter if {@code isVariadic() == true}
      */