Variable Declarations
When writing code, it's good practice to use descriptive variable names. For instance, noise to represent a noise signal, or saw for a sawtooth wave.
Most programming languages prevent the use of reserved keywords (e.g., for, while, null) as variable names. The bell language does this as well — using a reserved word like print as a variable name will raise a parser error.
However, this is not the case for functions and names defined in bellplay~. These are not treated as native bell functions, so defining a variable with the same name (e.g., render) will silently override the original value — without any warnings or errors.
Overwriting global bellplay~ function names (such as render, saw, noise, etc.) with your own global variables will break the application, often in ways that are hard to debug. There is no warning when this happens — the parser will accept the code, and the application will behave incorrectly.
To avoid such conflicts, always declare variables locally, using the $ prefix (e.g., $saw). Avoid global declarations unless absolutely necessary, and only after verifying that the name does not already exist in bellplay~.
If a name conflict does occur, restart the application to restore the original environment.
## generate a buffer with the global function `saw` and store it in the local variable `$saw`
$saw = saw(@frequency 220 @duration 1000);
$saw.transcribe(@gain .15);
## generate a second buffer with the global function `saw` and override the previous value of the `$saw` variable
## note that since the `$saw` variable is local (prefixed with `$`), it does not override the global `saw` function.
$saw = saw(@frequency 330 @duration 1000);
$saw.transcribe(@gain .15);
## render transcribed buffers
render()
By convention, global variables in bell should be capitalized to distinguish them from local variables:
MyGlobalVariable = "I'm global!"; ## good
myglobalvariable = "I'm dangerously global!"; ## not recommended
$mylocalvariable = "I'm local!"