You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
141 lines
4.4 KiB
141 lines
4.4 KiB
inspect.lua
|
|
===========
|
|
|
|
[](https://travis-ci.org/kikito/inspect.lua)
|
|
|
|
This function transform any Lua table into a human-readable representation of that table.
|
|
|
|
The objective here is human understanding (i.e. for debugging), not serialization or compactness.
|
|
|
|
Examples of use
|
|
===============
|
|
|
|
`inspect` has the following declaration: `str = inspect(value, <options>)`.
|
|
|
|
`value` can be any Lua value. `inspect` transforms simple types (like strings or numbers) into strings. Tables, on the other
|
|
hand, are rendered in a way a human can undersand.
|
|
|
|
"Array-like" tables are rendered horizontally:
|
|
|
|
inspect({1,2,3,4}) == "{ 1, 2, 3, 4 }"
|
|
|
|
"dictionary-like" tables are rendered with one element per line:
|
|
|
|
inspect({a=1,b=2}) == [[{
|
|
a = 1,
|
|
b = 2
|
|
}]]
|
|
|
|
The keys will be sorted alphanumerically when possible.
|
|
|
|
"Hybrid" tables will have the array part on the first line, and the dictionary part just below them:
|
|
|
|
inspect({1,2,3,b=2,a=1}) == [[{ 1, 2, 3,
|
|
a = 1,
|
|
b = 2
|
|
}]]
|
|
|
|
Tables can be nested, and will be indented with two spaces per level.
|
|
|
|
inspect({a={b=2}}) == [[{
|
|
a = {
|
|
b = 2
|
|
}
|
|
}]]
|
|
|
|
Functions, userdata and any other custom types from Luajit are simply as `<function x>`, `<userdata x>`, etc.:
|
|
|
|
inspect({ f = print, ud = some_user_data, thread = a_thread} ) == [[{
|
|
f = <function 1>,
|
|
u = <userdata 1>,
|
|
thread = <thread 1>
|
|
}]])
|
|
|
|
If the table has a metatable, inspect will include it at the end, in a special field called `<metatable>`:
|
|
|
|
inspect(setmetatable({a=1}, {b=2}) == [[{
|
|
a = 1
|
|
<metatable> = {
|
|
b = 2
|
|
}
|
|
}]])
|
|
|
|
`inspect` can handle tables with loops inside them. It will print `<id>` right before the table is printed out the first time, and replace the whole table with `<table id>` from then on, preventing infinite loops.
|
|
|
|
a = {1, 2}
|
|
b = {3, 4, a}
|
|
a[3] = b -- a references b, and b references a
|
|
inspect(a) = "<1>{ 1, 2, { 3, 4, <table 1> } }"
|
|
|
|
Notice that since both `a` appears more than once in the expression, it is prefixed by `<1>` and replaced by `<table 1>` every time it appears later on.
|
|
|
|
### options.depth
|
|
|
|
`inspect`'s second parameter allows controlling the maximum depth that will be printed out. When the max depth is reached, it'll just return `{...}`:
|
|
|
|
local t5 = {a = {b = {c = {d = {e = 5}}}}}
|
|
|
|
inspect(t5, {depth = 4}) == [[{
|
|
a = {
|
|
b = {
|
|
c = {
|
|
d = {...}
|
|
}
|
|
}
|
|
}
|
|
}]]
|
|
|
|
inspect(t5, {depth = 2}) == [[{
|
|
a = {
|
|
b = {...}
|
|
}
|
|
}]])
|
|
|
|
`options.depth` defaults to infinite (`math.huge`).
|
|
|
|
### options.filter
|
|
|
|
Sometimes it might be convenient to "filter out" some parts of the output. The `options.filter` option can do that.
|
|
|
|
`options.filter` accepts a table of values. Any value on that table will be rendered as `<filtered>`. This is useful for hiding things like long complex tables that are not interesting for the task at hand, for example an unuseful complex metatable.
|
|
|
|
local person = {name = 'peter'}
|
|
setmetatable(person, complex_mt)
|
|
inspect(x, {filter = {complex_mt}}) == [[{
|
|
name = "peter",
|
|
<metatable> = <filtered>
|
|
}]]
|
|
|
|
`options.filter` can also be a function. The function must return true for the values that must be filtered out.
|
|
|
|
local isEvenNumber = function(x) return type(x) == 'number' and x % 2 == 0 end
|
|
|
|
inspect({1,2,3,4,5}, {filter = isEvenNumber}) == "{ 1, <filtered>, 3, <filtered>, 5 }"
|
|
|
|
|
|
Gotchas / Warnings
|
|
==================
|
|
|
|
This method is *not* appropiate for saving/restoring tables. It is ment to be used by the programmer mainly while debugging a program.
|
|
|
|
Installation
|
|
============
|
|
|
|
Just copy the inspect.lua file somewhere in your projects (maybe inside a /lib/ folder) and require it accordingly.
|
|
|
|
Remember to store the value returned by require somewhere! (I suggest a local variable named inspect, altough others might like table.inspect)
|
|
|
|
local inspect = require 'inspect'
|
|
-- or --
|
|
table.inspect = require 'inspect'
|
|
|
|
Also, make sure to read the license file; the text of that license file must appear somewhere in your projects' files.
|
|
|
|
Specs
|
|
=====
|
|
|
|
This project uses [busted](http://olivinelabs.com/busted/) for its specs. If you want to run the specs, you will have to install telescope first. Then just execute the following from the root inspect folder:
|
|
|
|
busted
|
|
|
|
|
|
|