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gensym

gensym([tag])

Generates a symbol which will not conflict with other variable names.

Examples

gensym([tag])

Generate a symbol which will not conflict with other variable names.

julia> gensym()
Symbol("##439")

julia> gensym("temp")
Symbol("##temp#440")

Here are some common examples of using gensym:

1. Create a unique symbol without a tag:

   julia> gensym()
   Symbol("##441")

   This example generates a unique symbol without providing a specific tag.

2. Create a unique symbol with a tag:

   julia> gensym("temp")
   Symbol("##temp#442")

   In this example, a unique symbol is generated with the tag "temp".

3. Avoid variable naming conflicts:

   julia> x = 5;
   julia> y = gensym("x");
   julia> eval(:($y = 10))
   10
   julia> x
   5
   julia> x == eval(y)
   false

   By using gensym, you can generate a symbol that does not conflict with existing variable names. In this case, the symbol generated with the tag "x" (gensym("x")) is assigned a different value than the existing variable x.

Common mistake example:

julia> gensym(x)
ERROR: UndefVarError: x not defined
Stacktrace:
...

In this example, the variable x is used as an argument to gensym without being defined. It's important to provide a string as the argument to gensym, which serves as a tag, rather than a variable name directly.

See Also

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