Expression language (#363)

* Configured the sql package Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Bootstrap implementation Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Literal done Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * More progress Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Progress Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Sync contract Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Fix type cohercion for event type system Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * In expression + sync grammar Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Implemented binary expressions Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Implemented Like expression Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Big refactor Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * More testing Fix math Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Implemented all the functions! Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Refactored logical expressions implementation More testing Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * More coverage and tests Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Fixed ConcatFunction and added ConcatWSFunction Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Fixed IN type casting Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Added ABS function Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Fix SUBSTRING implementation Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * More nits Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * WIP Javadoc-ing Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Fix division by 0 Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Bootstrapped TCK Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Added comparison operators to tck Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Added logical operators, case sensitivity and casting functions Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Copied all the tests to the tck Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Removed Java tests now covered by the TCK Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Added integer builtin test case Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Added fail fast evaluation mode Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * More changes More Javadoc Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Typo Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Fix bad javadoc Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Another CONCAT_WS test case Signed-off-by: Francesco Guardiani <francescoguard@gmail.com> * Import yaml just for testing Signed-off-by: Francesco Guardiani <francescoguard@gmail.com>
cloudevents · Apr 28, 2021 · 2730ae4 · 2730ae4
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diff --git a/pom.xml b/pom.xml
@@ -76,6 +76,7 @@
         <module>http/restful-ws</module>
         <module>kafka</module>
         <module>spring</module>
+        <module>sql</module>
     </modules>
 
     <properties>

diff --git a/sql/pom.xml b/sql/pom.xml
@@ -0,0 +1,93 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>cloudevents-parent</artifactId>
+        <groupId>io.cloudevents</groupId>
+        <version>2.1.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>cloudevents-sql</artifactId>
+
+    <properties>
+        <module-name>io.cloudevents.sql</module-name>
+        <antlr.version>4.9.2</antlr.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.cloudevents</groupId>
+            <artifactId>cloudevents-api</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.antlr</groupId>
+            <artifactId>antlr4-runtime</artifactId>
+            <version>${antlr.version}</version>
+        </dependency>
+
+        <!-- Test deps -->
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>${junit-jupiter.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.cloudevents</groupId>
+            <artifactId>cloudevents-core</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.cloudevents</groupId>
+            <artifactId>cloudevents-json-jackson</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-yaml</artifactId>
+            <version>2.11.2</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.cloudevents</groupId>
+            <artifactId>cloudevents-core</artifactId>
+            <classifier>tests</classifier>
+            <type>test-jar</type>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.antlr</groupId>
+                <artifactId>antlr4-maven-plugin</artifactId>
+                <version>${antlr.version}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>antlr4</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <visitor>true</visitor>
+                    <listener>true</listener> <!-- TODO do we need the listener? -->
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>
diff --git a/sql/src/main/antlr4/imports/CESQLLexer.g4 b/sql/src/main/antlr4/imports/CESQLLexer.g4
@@ -0,0 +1,79 @@
+lexer grammar CESQLLexer;
+
+// NOTE:
+// This grammar is case-sensitive, although CESQL keywords are case-insensitive.
+// In order to implement case-insensitivity, check out
+// https://github.com/antlr/antlr4/blob/master/doc/case-insensitive-lexing.md#custom-character-streams-approach
+
+// Skip tab, carriage return and newlines
+
+SPACE:                               [ \t\r\n]+    -> skip;
+
+// Fragments for Literal primitives
+
+fragment ID_LITERAL:                 [a-zA-Z0-9]+;
+fragment DQUOTA_STRING:              '"' ( '\\'. | '""' | ~('"'| '\\') )* '"';
+fragment SQUOTA_STRING:              '\'' ('\\'. | '\'\'' | ~('\'' | '\\'))* '\'';
+fragment INT_DIGIT:                  [0-9];
+fragment FN_LITERAL:                 [A-Z] [A-Z_]*;
+
+// Constructors symbols
+
+LR_BRACKET:                          '(';
+RR_BRACKET:                          ')';
+COMMA:                               ',';
+SINGLE_QUOTE_SYMB:                   '\'';
+DOUBLE_QUOTE_SYMB:                   '"';
+
+fragment QUOTE_SYMB
+    : SINGLE_QUOTE_SYMB | DOUBLE_QUOTE_SYMB
+    ;
+
+// Operators
+// - Logic
+
+AND: 'AND';
+OR: 'OR';
+XOR: 'XOR';
+NOT: 'NOT';
+
+// - Arithmetics
+
+STAR:                                '*';
+DIVIDE:                              '/';
+MODULE:                              '%';
+PLUS:                                '+';
+MINUS:                               '-';
+
+// - Comparison
+
+EQUAL:                        '=';
+NOT_EQUAL:                    '!=';
+GREATER:                      '>';
+GREATER_OR_EQUAL:             '>=';
+LESS:                         '<';
+LESS_GREATER:                 '<>';
+LESS_OR_EQUAL:                '<=';
+
+// Like, exists, in
+
+LIKE: 'LIKE';
+EXISTS: 'EXISTS';
+IN: 'IN';
+
+// Booleans
+
+TRUE: 'TRUE';
+FALSE: 'FALSE';
+
+// Literals
+
+DQUOTED_STRING_LITERAL:                      DQUOTA_STRING;
+SQUOTED_STRING_LITERAL:                      SQUOTA_STRING;
+INTEGER_LITERAL:                             INT_DIGIT+;
+
+// Identifiers
+
+IDENTIFIER:                                 [a-zA-Z]+;
+IDENTIFIER_WITH_NUMBER: [a-zA-Z0-9]+;
+FUNCTION_IDENTIFIER_WITH_UNDERSCORE:                        [A-Z] [A-Z_]*;
diff --git a/sql/src/main/antlr4/io/cloudevents/sql/generated/CESQLParser.g4 b/sql/src/main/antlr4/io/cloudevents/sql/generated/CESQLParser.g4
@@ -0,0 +1,62 @@
+grammar CESQLParser;
+
+import CESQLLexer;
+
+// Entrypoint
+cesql: expression EOF;
+
+// Structure of operations, function invocations and expression
+expression
+    : functionIdentifier functionParameterList #functionInvocationExpression
+    // unary operators are the highest priority
+    | NOT expression #unaryLogicExpression
+    | MINUS expression # unaryNumericExpression
+    // LIKE, EXISTS and IN takes precedence over all the other binary operators
+    | expression NOT? LIKE stringLiteral #likeExpression
+    | EXISTS identifier #existsExpression
+    | expression NOT? IN setExpression #inExpression
+    // Numeric operations
+    | expression (STAR | DIVIDE | MODULE) expression #binaryMultiplicativeExpression
+    | expression (PLUS | MINUS) expression #binaryAdditiveExpression
+    // Comparison operations
+    | expression (EQUAL | NOT_EQUAL | LESS_GREATER | GREATER_OR_EQUAL | LESS_OR_EQUAL | LESS | GREATER) expression #binaryComparisonExpression
+    // Logic operations
+    |<assoc=right> expression (AND | OR | XOR) expression #binaryLogicExpression
+    // Subexpressions and atoms
+    | LR_BRACKET expression RR_BRACKET #subExpression
+    | atom #atomExpression
+    ;
+
+atom
+    : booleanLiteral #booleanAtom
+    | integerLiteral #integerAtom
+    | stringLiteral #stringAtom
+    | identifier #identifierAtom
+    ;
+
+// Identifiers
+
+identifier
+    : (IDENTIFIER | IDENTIFIER_WITH_NUMBER)
+    ;
+functionIdentifier
+    : (IDENTIFIER | FUNCTION_IDENTIFIER_WITH_UNDERSCORE)
+    ;
+
+// Literals
+
+booleanLiteral: (TRUE | FALSE);
+stringLiteral: (DQUOTED_STRING_LITERAL | SQUOTED_STRING_LITERAL);
+integerLiteral: INTEGER_LITERAL;
+
+// Functions
+
+functionParameterList
+    : LR_BRACKET ( expression ( COMMA expression )* )? RR_BRACKET
+    ;
+
+// Sets
+
+setExpression
+    : LR_BRACKET expression ( COMMA expression )* RR_BRACKET // Empty sets are not allowed
+    ;
diff --git a/sql/src/main/java/io/cloudevents/sql/EvaluationContext.java b/sql/src/main/java/io/cloudevents/sql/EvaluationContext.java
@@ -0,0 +1,36 @@
+package io.cloudevents.sql;
+
+import org.antlr.v4.runtime.misc.Interval;
+
+/**
+ * This class wraps some elements of the evaluation context,
+ * required to throw {@link EvaluationException} when an error occurs while evaluating a function.
+ */
+public interface EvaluationContext {
+
+    /**
+     * @return the interval of the original expression string.
+     */
+    Interval expressionInterval();
+
+    /**
+     * @return the text of the original expression string.
+     */
+    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);
+}