Nasal library/debug: Difference between revisions
Red Leader (talk | contribs) (→Functions: Start local()) |
Red Leader (talk | contribs) (→local(): Add examples) |
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|param1 = frame | |param1 = frame | ||
|param1text = Optional integer specifying the frame. Corresponds to the argument given to {{func link|caller()}}. | |param1text = Optional integer specifying the frame. Corresponds to the argument given to {{func link|caller()}}. | ||
|example1 = | |example1 = var n = 12; | ||
|example2 = | debug.local(); # prints "{ n: 12, arg: [] }" | ||
|example2 = var sqr = func(a){ | |||
debug.local(); # prints "{ a: 16 }" | |||
debug.local(1); # prints "{ sqr: <func>, arg: [] }" | |||
return a * a; | |||
} | |||
print(sqr(16)); | |||
}} | }} | ||
Revision as of 09:45, 24 November 2016
Work in progress This article or section will be worked on in the upcoming hours or days. See history for the latest developments. |
The FlightGear forum has a subforum related to: Nasal Scripting |
Nasal scripting |
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Nasal internals |
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Memory Management (GC) |
This page contains documentation for the debug
namespace in Nasal. This namespace provides various useful APIs for debugging Nasal code. The debug
namespace is sourced from fgdata/Nasal/debug.nas.
Functions
attributes()
debug.attributes(p[, verbose[, color]]);
Returns a string showing the attributes of the node, in the form (type[, attr[, Lnum[, #refs]])
. See the table below for explanation.
Data | Meaning |
---|---|
type | Type of node as returned by props.Node.getType() .
|
attr | Various attribute flags, see props.Node.getAttribute() . "r" = read protected, "w" = write protected, "R" = trace read, "W" = trace write, "A" = archive, "U" = userarchive, "P" = preserve, and "T" = tied.
|
num | Number of listeners, if any. |
refs | This argument will be shown if verbose is true. Tells the number of references to the node. Note that all nodes have two references by default, but this tells the number of extra references. |
- p
- Mandatory
props.Node
object. - verbose
- Optional bool specifying whether to show the number of times the node is referenced. Defaults to 1 (true).
- color
- Optional bool specifying whether to output the string with an ANSI color code . Defaults to
nil
.
Examples
var node = props.globals.getNode("/sim/time/gmt");
print(debug.attributes(node)); # prints "(STRING, AT, #1)" - string, archive, tied, 1 extra ref
var node = props.Node.new();
node.setIntValue(12);
node.setAttribute(17);
print(debug.attributes(node)); # prints "(INT, wR)" - integer, write protected, trace read
var node = props.globals.getNode("/sim/signals/fdm-initialized");
print(debug.attributes(node)); # prints "(BOOL, L6, #16)" - bool, 6 listeners, 16 extra refs
backtrace()
debug.backtrace([desc]);
When called, this function prints the backtrace , also printing the local variables at each level.
- desc
- Optional extra description to add.
Examples
var myFunc = func(a){
multiply(a, 2);
}
var multiply = func(x, y){
debug.backtrace();
}
myFunc(2);
var myFunc = func(a){
multiply(a, 2);
}
var multiply = func(x, y){
debug.backtrace("multiply() function");
}
myFunc(2);
bt()
debug.bt([desc]);
Shortcut for backtrace()
. See doc there
benchmark()
debug.benchmark(label, fn[, repeat[, output]]);
Analyses the amount of time a function takes to run. If repeat is given and output is not, the time taken to repeat the function the given amount off times will be printed. If both are given, the return value of each repeat of the function will be returned in a vector output.
- label
- Label to add to the output.
- fn
- Function to call.
- repeat
- Optional integer specifying how many times the function is to be run. If not given, the function will be run once.
- output
- Optional vector that will be returned with the return value of each function.
Examples
var test = func(){
var children = props.globals.getNode("sim").getChildren();
var vec = [];
foreach(var child; children){
append(vec, child.getChildren());
}
return vec;
}
var result = debug.benchmark("test()", test);
debug.dump(result);
var test = func(){
var children = props.globals.getNode("sim").getChildren();
var vec = [];
foreach(var child; children){
append(vec, child.getChildren());
}
return vec;
}
debug.benchmark("test()", test, 10);
var test = func(){
var children = props.globals.getNode("sim").getChildren();
var vec = [];
foreach(var child; children){
append(vec, child.getChildren());
}
return vec;
}
var result = debug.benchmark("test()", test, 10, []); # this example may cause a small pause
debug.dump(result);
benchmark_time()
debug.benchmark_time(fn[, repeat[, output]]);
Behaves in exactly the same way as benchmark()
, but returns the amount of time taken, rather than printing it out.
- fn
- Function to call.
- repeat
- Optional integer specifying how many times the function is to be run. If not given, the function will be run once.
- output
- Optional vector that will be returned with the return value of each function.
Examples
var test = func(){
var children = props.globals.getNode("sim").getChildren();
var vec = [];
foreach(var child; children){
append(vec, child.getChildren());
}
return vec;
}
print(debug.benchmark_time(test));
var test = func(){
var children = props.globals.getNode("sim").getChildren();
var vec = [];
foreach(var child; children){
append(vec, child.getChildren());
}
return vec;
}
print(debug.benchmark_time(test, 10));
var test = func(){
return getprop("/sim/time/gmt");
}
print(debug.benchmark_time(test, 1000, var res = []));
debug.dump(res);
dump()
debug.dump([arg[, arg[, ...]]]);
Dumps the given arguments in the console. If no arguments of given, the local namespace will be dumped.
- arg
- Anything. Literally, anything. There may be as may arguments as you like. If more than one argument is given, each will be dumped separately with an index.
Examples
var x = nil;
debug.dump(); # prints "{ x: nil, arg: [] }"
debug.dump("Hello, World!"); # 'Hello, World!'
debug.dump(1234); # 1234
debug.dump(nil); # nil
debug.dump(["a", "b", "c"]); # ['a', 'b', 'c']
debug.dump({ a: 1, b: 2, c: 3 }); # { a: 1, b: 2, c: 3 }
debug.dump(props.Node.new()); # < = nil (NONE)>
debug.dump(airportinfo()); # <airport>
debug.dump(func(a){ print(a); }); # <func>
debug.dump( # dump, showing the index of each argument
"Hello, World!",
1234,
nil,
["a", "b", "c"],
{ a: 1, b: 2, c: 3 },
props.Node.new(),
airportinfo(),
func(a){ print(a); },
);
isnan()
debug.isnan(num);
Checks whether a number actually is a valid number and returns 0 (false) if it is and 1 (true) if it is not.
- num
- Number to check.
Examples
print(debug.isnan(1.234)); # prints "0" (1.234 is valid)
print(debug.isnan(1/0)); # prints "1" (division by 0 is undefined)
local()
debug.local([frame]);
Prints and also returns a hash containing all the local variables.
- frame
- Optional integer specifying the frame. Corresponds to the argument given to
caller()
.
Examples
var n = 12;
debug.local(); # prints "{ n: 12, arg: [] }"
var sqr = func(a){
debug.local(); # prints "{ a: 16 }"
debug.local(1); # prints "{ sqr: <func>, arg: [] }"
return a * a;
}
print(sqr(16));