Icon+Unicon/Intro: Difference between revisions
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=== Data Types === |
=== Data Types === |
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The following summarizes the data types of Icon and Unicon. Each type is described and its characteristics are noted: |
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* mutable or immutable - changeable or not |
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* coercible or not - coercion is implicit type conversion by operations |
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* convertible or not - convertible through explicit type conversion |
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==== &null ==== |
==== &null ==== |
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&null is unique. It is a data type with only a single value, one instance only. While this may sound odd at first, &null is at the core of Icon/Unicon and contributes to the power and robustness of the language. Specifically, &null arose to overcome a short coming that any [[SNOBOL4]] programmer will be familiar with. Consider the following SNOBOL code: |
&null (immutable, uncoercible, unconvertable) is unique. It is a data type with only a single value, one instance only. While this may sound odd at first, &null is at the core of Icon/Unicon and contributes to the power and robustness of the language. Specifically, &null arose to overcome a short coming that any [[SNOBOL4]] programmer will be familiar with. Consider the following SNOBOL code: |
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<lang Snobol> numb1 = 2 |
<lang Snobol> numb1 = 2 |
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