Category:Elena: Difference between revisions
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To create a simple console program we have to declare the program symbol in the project root namespace: |
To create a simple console program we have to declare the program symbol in the project root namespace: |
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public program |
public program |
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[ |
[ |
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] |
] |
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Everything in ELENA is an object. To interact with it we have to send a message. The simplest (generic, i.e. without an explicit signature) message consists of an action and a parameter list. |
Everything in ELENA is an object. To interact with it we have to send a message. The simplest (generic, i.e. without an explicit signature) message consists of an action and a parameter list. |
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The statement should be terminated by a dot (ELENA is inspired by Smalltalk and uses its syntax notations). |
The statement should be terminated by a dot (ELENA is inspired by Smalltalk and uses its syntax notations). |
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public program |
public program |
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[ |
[ |
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console writeLine("Hello!") |
console writeLine("Hello!") |
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] |
] |
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In our example the action is writeLine and the parameter list consists of a single literal constant. The message target is console object (implementing input / output operations with a program console). |
In our example the action is writeLine and the parameter list consists of a single literal constant. The message target is console object (implementing input / output operations with a program console). |
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Several message operations can be done in a single statement separated by a semicolon: |
Several message operations can be done in a single statement separated by a semicolon: |
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public program |
public program |
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[ |
[ |
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console writeLine("Hello!"); writeLine("How are you?"). |
console writeLine("Hello!"); writeLine("How are you?"). |
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] |
] |
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The result will be: |
The result will be: |
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We may read a user input by sending readLine message without parameters: |
We may read a user input by sending readLine message without parameters: |
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public program |
public program |
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[ |
[ |
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console write("What is your name:"); writeLine("Hello " + console readLine). |
console write("What is your name:"); writeLine("Hello " + console readLine). |
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] |
] |
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The result will be: |
The result will be: |
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