Control Structures: Difference between revisions
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{{TOCright}} | {{TOCright}} | ||
=Conditional= | ==Conditional== | ||
==if== | ===if=== | ||
{{ | {{ | ||
CodeSample| | CodeSample| | ||
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// curly braces aren't required if only one statement follows the conditional | // curly braces aren't required if only one statement follows the conditional | ||
</syntaxhighlight>}} | </syntaxhighlight>}} | ||
==else== | ===else=== | ||
{{ | {{ | ||
CodeSample| | CodeSample| | ||
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</syntaxhighlight>}} | </syntaxhighlight>}} | ||
==else if== | ===else if=== | ||
{{ | {{ | ||
CodeSample| | CodeSample| | ||
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</syntaxhighlight>}} | </syntaxhighlight>}} | ||
==switch== | ===switch=== | ||
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break; | break; | ||
} | } | ||
=Looping= | ==Looping== | ||
== while == | ===while=== | ||
while (boolean) | while (boolean) | ||
{} | {} | ||
== repeat until == | ===repeat until=== | ||
repeat | repeat | ||
{} | {} | ||
until (boolean); | until (boolean); | ||
== for == | ===for=== | ||
for x from a to b by c | for x from a to b by c | ||
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If you don't specify "c", it defaults to incrementing/decrementing by 1. The first iteration is at a and the last is at b (that is to say, it goes from a to b, inclusive). | If you don't specify "c", it defaults to incrementing/decrementing by 1. The first iteration is at a and the last is at b (that is to say, it goes from a to b, inclusive). | ||
== foreach == | ===foreach=== | ||
foreach x in map | foreach x in map | ||
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} | } | ||
See http://kolmafia.sourceforge.net/advanced.html#maps for more details on maps. | See http://kolmafia.sourceforge.net/advanced.html#maps for more details on maps. | ||
== continue/break == | ===continue/break=== | ||
Like many languages with looping structures, ASH supports the break and continue statements. All looping structures (for, while, repeat until, and foreach) support these statements. | Like many languages with looping structures, ASH supports the break and continue statements. All looping structures (for, while, repeat until, and foreach) support these statements. | ||
Revision as of 06:56, 14 March 2010
Conditional
if
if ( boolean )
{
// any statements here
// are only going to be executed
// if the boolean returns true
}
Single-statement conditionals may omit the curly braces.
if ( boolean )
// curly braces aren't required if only one statement follows the conditional
else
if ( boolean )
{
// statements if true
}
else
{
// the statements here
// are only going to be executed
// if the boolean returns false
}
else if
if ( boolean1 )
{
// statements if true
}
else if ( boolean2 )
{
// the statements here
// are only going to be executed
// if boolean1 returns false
// & boolean2 returns true
}
switch
switch (value) { case expression: statement statement ... break; default: statement statement ... break; }
Looping
while
while (boolean) {}
repeat until
repeat {} until (boolean);
for
for x from a to b by c
is the general case. You don't need to specify whether it's going up or down - although doing so by using upto or downto does allow a runtime check to make sure you didn't screw up.
If you don't specify "c", it defaults to incrementing/decrementing by 1. The first iteration is at a and the last is at b (that is to say, it goes from a to b, inclusive).
foreach
foreach x in map {}
"map" must be an aggregate - a map or a slice. x takes on each value of the map index in turn. If there is more than one index, x iterates over the first index.
For example:
boolean [int][string] map; map[15]["test"] = true; foreach int_index in map { print(int_index); //this will print '15' once, since there is only one valid value for this index foreach string_index in map[int_index] //this iterates over the "slice" of the map where 1 is fixed as the index { print(string_index); //This will print "test" once, since there is only one valid value for this index print(map[int_index][string_index]); //this will print "true" } }
So the output is
15 test true
Note that instead of nesting foreach statements, for a multidimensional map, two iterators can be used inline.
foreach x,y in map
is identical to
foreach x in map { foreach y in map[x] }
See http://kolmafia.sourceforge.net/advanced.html#maps for more details on maps.
continue/break
Like many languages with looping structures, ASH supports the break and continue statements. All looping structures (for, while, repeat until, and foreach) support these statements.
break;
Breaks out of the smallest enclosing loop. In a switch statement, breaks out of the switch statement. Execution resumes at the first statement after the end of the loop/switch statement.
continue;
Continues on to the next iteration of the loop (skipping any statments in this iteration that occur after the continue statement). In a switch statement, continue is allowed iff the switch is inside a loop, and acts as any other continue.