Variable size/Set: Difference between revisions
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(→{{header|Perl}}: + Tcl) |
(→{{header|Tcl}}: + length limit) |
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In Tcl, all values are (Unicode) strings. Their size is measured in characters, and the minimum size of a string is of course 0. |
In Tcl, all values are (Unicode) strings. Their size is measured in characters, and the minimum size of a string is of course 0. |
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However, one can arrange, via write traces, that the value of a variable is reformatted to bigger size. Examples, from an interactive [[tclsh]] session: |
However, one can arrange, via write traces, that the value of a variable is reformatted to bigger size. Examples, from an interactive [[tclsh]] session: |
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% trace var foo w {format_trace %10s} |
% trace var foo w {format_trace %10s} |
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% trace var grill w {format_trace %-10s} |
% trace var grill w {format_trace %-10s} |
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% puts "/[set grill bar]/" |
% puts "/[set grill bar]/" |
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/bar / |
/bar /</lang> |
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..or limit its size to a certain length: |
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% |
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<lang Tcl>% proc range_trace {n _var el op} {upvar 1 $_var v; set v [string range $v 0 [incr n -1]]} |
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</lang> |
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% trace var baz w {range_trace 2} |
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% set baz Frankfurt |
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{{Omit From|E}} |
{{Omit From|E}} |
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