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Variables defined in a block will always cease to exist after the blocks end. (prolang.y, lex.c) git-svn-id: svn://svn.bearnip.com/ldmud/trunk@2867 56160b6e-f8f8-0310-bd54-bccebfe6a2f2
48 lines
1.5 KiB
Text
48 lines
1.5 KiB
Text
NAME
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block
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DESCRIPTION
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A block is a special statment, that begins with '{', contains
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a list of statements, and ends with '}'.
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The block may define local variables. If for a variable no
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initialisation is given, the variable is initialised to 0 every
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time the block is entered. Otherwise, the initialisation
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expression is evaluated and its result assigned to the variable
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everytime the block is entered.
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Example definitions are:
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int i;
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int j = 3;
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int k = 3 * j, l;
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Here, i and l are both initialised to 0; j is initialised
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to 3, and k is initialised to 9 (3 * j).
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Local variables defined in a block are visible only until the
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end of the block. Definitions in an inner block hide definitions in
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outer blocks.
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HISTORY
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Up to 3.2.7 local variables were visible (from their point of
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definition) in the whole function. That is, code like
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do {
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int res;
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res = ...
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} while (res == 5);
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write(res);
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was perfectly legal. It is no longer, as 'res' ceases to exist
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with the closing '}' of the while().
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Up to 3.5.0 you could get this old behaviour back with the
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#pragma no_local_scopes and switch it off again with
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#pragma local_scopes.
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Since 3.5.0 it is not possible to disable the local scope behaviour.
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Up to 3.2.8, local variables could not be initialised in their
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definition.
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