QueryStream is a Java library for continuous query processing and ternary operator improvement.
- Able to express naturally as if writing English sentences.
- Confusing symbols(!, &&, ||, etc.) can be expressed in words(such as not, and, or).
- Improved Java ternary operator which is less readable.
- Provides methods such as throwing exceptions.
- requires JDK 1.8 or higher.
To add a dependency using maven :
<dependency>
<groupId>io.github.eatnuh</groupId>
<artifactId>querystream</artifactId>
<version>1.0</version>
</dependency>To add a dependency using gradle :
dependencies {
implementation 'io.github.eatnuh:querystream:1.0'
}Creating a query starts by calling the static method ask or askNot.
import static querystream.QueryStream.*;
public class Main {
private static final boolean A = true;
private static final boolean B = false;
public static void main(String[] args) {
QueryStream.ask(A); // A
QueryStream.askNot(B); // Not B
// if static import, you can write
ask(A); // A
askNot(B); // B
}
}import static querystream.QueryStream.*;
public class Main {
private static final boolean A = true;
private static final boolean B = false;
public static void main(String[] args) {
boolean resultAisTrue = ask(A).isTrue(); // return A is true?
boolean resultAisFalse = askNot(B).isFalse(); // return Not B is False?
boolean resultAisThat = ask(A).is(true); // return A is param?
}
}import static querystream.QueryStream.*;
public class Main {
private static final boolean A = true;
private static final boolean B = false;
private static final boolean C = true;
public static void main(String[] args) {
ask(A).and(B); // A and B
ask(A).andNot(B); // A and Not B
askNot(B).orNot(A); // Not B or Not A
askNot(A).and(B).orNot(C); // Not A and B or Not C
}
}import static querystream.QueryStream.*;
public class Main {
private static final boolean A = true;
private static final boolean B = false;
private static final boolean C = true;
public static void main(String[] args) {
ask(A).and(B).reAsk(C); // initialize C
ask(A).and(B).reAskNot(C).and(B); // initialize Not C and B
}
}import static querystream.QueryStream.*;
public class Main {
private static final boolean A = true;
private static final boolean B = false;
private static final boolean C = true;
public static void main(String[] args) {
ask(A).then(() -> System.out.println("A is true")); // run if A is true.
ask(B).orElse(() -> System.out.println("B is false")); // run if A is false.
}
}import static querystream.QueryStream.*;
public class Main {
private static final boolean A = true;
private static final boolean B = false;
private static final boolean C = true;
public static void main(String[] args) {
ask(A).thenThrow(() -> new RuntimeException()); // throws if A is true.
ask(B).orElseThrow(() -> new RuntimeException()); // throws if A is false.
}
}thenReturn, orElseReturn method return new QueryReturnStream instance
import static querystream.QueryStream.*;
public class Main {
private static final boolean A = true;
private static final boolean B = false;
private static final boolean C = true;
private static final String VALUE1 = "value1";
private static final String VALUE2 = "value2";
private static final String VALUE3 = "value3";
private static final String VALUE4 = "value4";
public static void main(String[] args) {
// return VALUE1 if A is true,
// otherwise VALUE2
String v1 = ask(A).thenReturn(VALUE1).orElse(VALUE2);
// return VALUE1 if B is false,
// otherwise VALUE2
String v2 = ask(B).orElseReturn(VALUE1).orElse(VALUE2);
// return VALUE1 if C is true,
// or else VALUE2 if A is true,
// otherwise VALUE3
String v3 = ask(C).thenReturn(VALUE1)
.orElseIf(A, VALUE2)
.orElse(VALUE3);
// return VALUE1 if Not C is false,
// or else VALUE2 if A is not true,
// or else VALUE3 if B is true,
// otherwise VALUE4
String v4 = askNot(C).orElseReturn(VALUE1)
.orElseIfNot(A, VALUE2)
.orElseIf(B, VALUE3)
.orElse(VALUE1);
}
}import static querystream.QueryReturnStream.*;
public class Main {
private static final boolean A = true;
private static final boolean B = false;
private static final boolean C = true;
private static final String VALUE1 = "value1";
private static final String VALUE2 = "value2";
private static final String VALUE3 = "value3";
private static final String VALUE4 = "value4";
public static void main(String[] args) {
// return VALUE1 if A is true,
// otherwise VALUE2
String v1 = ifTrueReturn(A, VALUE1).orElse(VALUE2);
// return VALUE1 if B is false,
// otherwise VALUE2
String v2 = ifFalseReturn(B, VALUE1).orElse(VALUE2);
// return VALUE1 if C is true,
// or else VALUE2 if A is true,
// otherwise VALUE3
String v3 = ifTrueReturn(C, VALUE1)
.orElseIf(A, VALUE2)
.orElse(VALUE3);
}
}MIT License
Copyright (c) 2022 김태훈
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