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| alvis:stepscounting [2013/12/31 10:47] marcin created | — (current) | ||
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| - | ====== Steps counting ====== | ||
| - | Let us focus on the **step** idea. It is necessary to distinguish between **code statements** and **steps**. Most of the Alvis statements e.g. **exec**, **exit**, etc. are **single-step statements**. On the other hand, **if**, **loop** and **select** are **multi-step statements**. We use recursion to count the number of steps for multi-step statements. For each of them, the first step enters the statement interior. Then, we count steps of statements put inside curly brackets. | ||
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| - | For a given statement //s//, let // | ||
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| - | Let us consider the piece of code shown in Listing 1. The steps number are put inside comments. For example, the step 7 denotes entering the **if** statement, while the step 8 denotes the **out** statement. | ||
| - | |||
| - | < | ||
| - | agent A { | ||
| - | i :: Int = 0; | ||
| - | loop { -- 1 | ||
| - | select { -- 2 | ||
| - | alt (i == 0) { | ||
| - | in p; -- 3 | ||
| - | i = 1; -- 4 | ||
| - | } | ||
| - | alt (i == 1) { | ||
| - | in q; -- 5 | ||
| - | i = 0; -- 6 | ||
| - | } | ||
| - | } | ||
| - | if(i == 1) { -- 7 | ||
| - | out p; -- 8 | ||
| - | } | ||
| - | else { | ||
| - | null; -- 9 | ||
| - | } | ||
| - | } | ||
| - | } | ||
| - | </ | ||
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| - | **FIXME** | ||
| - | |||
| - | **[[: | ||