TCL, How to name a variable that includes another variable

问题

In TCL, I'm writing a procedure that returns the depth of a clock. But since I have several clocks I want to name the var: depth_$clk

proc find_depth {} {    
    foreach clk $clocks {    
        …    
        set depth_$clk $max_depth    
        echo $depth_$clk    
    }    
}    

But I get:

Error: can't read "depth_": no such variable
        Use error_info for more info. (CMD-013)

回答1:

Your problem is this line:

    echo $depth_$clk    

The issue is that the syntax for $ only parses a limited set of characters afterwards for being part of the variable name; the $ is not part of that. Instead, you can use the set command with one argument; $ is effectively syntactic sugar for that, but the command lets you use complex substitutions.

    echo [set depth_$clk]

HOWEVER!

The real correct thing to do here is to switch to using an associative array. It's a bit larger change to your code, but lets you do more as you've got proper access to substitutions in array element names:

proc find_depth {} {
    foreach clk $clocks {
        …
        set depth($clk) $max_depth
        echo $depth($clk)
    }
}

来源：https://stackoverflow.com/questions/44605149/tcl-how-to-name-a-variable-that-includes-another-variable