What is the command bar supposed to be used for during run time? The only command I’ve used with it so far is output.clear()
I know it’s there for a reason, but exactly what is that reason? Also, just to reaffirm, the whole output window, command bar, and parameters are only for testing and debugging your program.
You could use it to check the value of a variable, execute some command. I’m sure people will find uses for it.
The parameters are, again, there for you to use however you like. I tend to use them to adjust parameters for my games to see what works.
In which context is the command entered into the command bar executed? I would assume the global environment of the program currently running?
That is correct, @gunnar_z.
I’m open to suggestions on how the command bar should return values — at the moment it returns them from the chunk, and prints the resulting values on the stack.
I am interested in understanding what the new ‘type a command’ bar does in pseudo-code terms. Is my attempt to replicate it below in processCommand reasonably accurate?
function setup()
parameter.text("Command", "")
parameter.action("Run", processCommand)
end
function draw() background(0) end
function processCommand()
local g = _G[Command]
if g then
print("=> "..tostring(g))
else
local f = loadstring(Command)
if f then
print("=> "..tostring((f()))) -- Extra () forces 'nil' if no result,
-- but clamps to first result only
else
print("attempt to call a string value")
end
end
end
```
I primarily use the Command Bar as a calculator and to see values in my variables.
But I’m also teaching my kids how to program (I guess we’re actually learning together). For the initial lessons, I make them use just the Command Bar. I don’t want to teach them about Codea’s ‘Draw’ loop or functions–just yet. The command bar is perfect to show the kids arithmetic operations, basic assignment, relational operators and variable types. Once they have these basics down, we’ll tackle the more complex constructs
One nice addition would be if the Command Bar allowed the ‘do’ block to force code, typed on multiple lines, to execute as one unit. For instance, I could use the Command Bar to write:
=> do
=> print("\
Here are some numbers: ")
=> for N = 1, 5, do
=> print(N)
=> end
=> print("\
That's the end of the numbers.")
=>end
And Codea wouldn’t execute it until I typed the ‘end’ that closed the ‘do’ loop. Apparently, Lua command line interpreters allow this use of ‘do.’ Why would this be valuable? Because it would help beginners going through Lua tutorials. They could focus on the control structure’s behavior without having to worry about the intimidating code inside Codea’s editor.
I used to be a technical writer for the Air Force back in my youth. One thing I learned: you have to move students from simple concepts to more complex. A user-friendly Command Bar might become part of a strategy that moved new Codea users from simple, one-line commands, to control structures, to functions, to classes, to full-fledged apps.
Hello @Ric_Esrey. In my ‘type a command’ replication above, as you may have spotted, you can enter (and see) multi-line code before pressing the ‘Run’ button.
Below, an improved version of the replication of the ‘type a command’ bar (perhaps, better than version 1.5.1 of the bar):
function setup()
parameter.text("Command", "")
parameter.action("Run", processCommand)
end
function draw() background(0) end
function processCommand()
local g = _G[Command]
if g then -- Is Command a global variable?
print("=> "..tostring(g))
else
local f = loadstring(Command)
if f then -- Is Command a valid function body?
local r = {f()} -- Preserve any results
local n = #r -- Count them
if n == 0 then -- No results?
print("=> nil") -- Strictly, 'no result' not 'nil'
else
for i = 1, n do
r[i] = tostring(r[i]) -- Convert to strings
end
print("=> "..table.concat(r, " ")) -- Output
end
else
print("attempt to call a string value") -- Error
end
end
end
```
@mpilgrem great code, thank you for sharing it. Couldn’t figure out how to make a dev console work while in full screen mode!
Greetings @mpilgrem. Actually, I hadn’t run your code until now, but you’re right; this is exactly what I need. Very useful… thanks.