1
0

Fixed docstring

This commit is contained in:
Jon Michael Aanes 2024-07-10 20:38:18 +02:00
parent fd03c384f6
commit 748fe7835e
Signed by: Jmaa
SSH Key Fingerprint: SHA256:Ab0GfHGCblESJx7JRE4fj4bFy/KRpeLhi41y4pF3sNA

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@ -1,205 +1,206 @@
--- Pretty
--
-- `pretty` is an advanced pretty printer for [Lua](lua.org). It's primarily a
-- debugging tool, aiming for human readability, by detecting pattern in the input
-- data, and creating an output string utilizing and highlighting those patterns.
--
-- ## Code Example
--
-- Setup is simple, use `pretty = require 'pretty'`, and you're good to go.
--
-- ```lua
-- > print(pretty( { 1, 2, 3 } ))
-- { 1, 2, 3 }
--
-- > print(pretty( { hello = 'world', num = 42 } ))
-- {
-- num = 42
-- hello = 'world'
-- }
--
-- > print(pretty( { abs = math.abs, max = math.max, some = function() end } ))
-- {
-- abs = builtin function (x) ... end
-- max = builtin function (x, ...) ... end
-- some = function () ... end
-- }
--
-- > print(pretty( math.abs ))
-- builtin function (x)
-- -- math.abs
-- -- Returns the absolute value of x
--
-- ...
-- end
-- ```
--
-- ## Motivation
--
-- This project is the outcome of my frustration with existing pretty printers, and
-- a desire to expand upon the pretty printer I developed for
-- [Xenoterm](https://gitfub.space/takunomi/Xenoterm). The original Xenoterm pretty
-- printer was much simpler than `pretty` - and the current is even simpler - but
-- the enhancements I make, when compared to other pretty printers, inspired me to
-- create `pretty`.
--
-- `pretty` sorts it's priorities like so:
--
-- 1. Human readability.
-- 2. Lua-compatible output.
-- 3. Customization.
--
-- I'd rather have good defaults than provide a ton of customization options. If an
-- structure avoids easy representation in Lua, I'd rather extend the syntax, than
-- lose the info.
--
-- Another aspect where `pretty` shines is in exploratory programming, when
-- attempting to avoid reliance on outside documentation. The amount of information
-- `pretty` exposes varies by the data you are inspecting. If you're inspecting
-- a list of functions, their function signatures are visible, but if you're
-- inspecting a single function, documentation and source location may appear if
-- available.
--
-- ## Features
--
-- - Written in good-old pureblood Lua, with support for PUC Lua 5.0+ and
-- LuaJIT 2.0+.
-- - Redefining what it means to be "human readable":
-- * Is multi-line centric, to aid readablitiy.
-- * Indention and alignment of keys-value pairs.
-- * Keys-value pairs are [properly](http://www.davekoelle.com/alphanum.html)
-- sorted by key type and thereafter alphabetically.
-- * The format and structure of output changes depending upon the input.
-- Maps appear differently to deeply nested tables to long sequences
-- with short strings to short lists.
-- * Uses the standard `debug` library to gain information about functions
-- and other advanced structures.
--
-- ## Installation
--
-- `pretty` is loadable directly with `require`. Either clone or download this
-- repository. Where you place it, depends upon what you want to do:
--
-- 1. **You want `pretty` in a specific project**: Place the `pretty` folder
-- somewhere in your project, and `require` it from one of your project files.
-- 2. **You want `pretty` on your system**: Place the `pretty` folder such that
-- it's visible from your Lua-path. On my system this might be
-- `/usr/local/share/lua/5.1/`. Now you can `require` it from anywhere.
--
-- ## API Documentation
--
-- `pretty` exposes a single function, the `pretty` function itself. It's function
-- signature is `pretty(value, options)`. `value` can be any Lua value. `options`
-- must be a table.
--
-- ### List of options
--
-- `pretty` is sure to complain if you give it an unknown option, or if you give an
-- option a bad value.
--
-- - `indent: string`: The string to indent with. Four spaces by default.
--
-- ## TODO
--
-- Tasks to be done before `pretty` can be called version 1.0.0, in order of
-- priority:
--
-- - Add a dedicated unicode submodule, to handle some minor alignment and
-- character escaping issues. `pretty` should escape all malformed unicode
-- sequences.
-- - Align numbers towards right for tabular views.
-- - Add support for `setmetatable`, and exploring values in metatables.
-- - Provide nice formatting for `cdata` datatype in LuaJIT.
-- - Find a better name than `pretty`.
-- - Enhance internal structure some amount. See `TODO` markers in files.
--
-- It would be nice to have the following, but these are secondary:
--
-- - Add option for colored output. Primarily syntax highlighting, but also
-- [BlueJ-style](www.bluej.org/about.html) scope highlighting, with some faint
-- background colors.
-- - Expand on the comment output in output, for `__tostring` methods, and global
-- namespaces like `io` or `math`.
-- - Fit output within a predefined width limit. Default to 80.
-- - Look into tool for understanding complex structures with recursive
-- definitions. Whatever modes are thought up, they should be automatic modes,
-- not an options. Should at least include modes for self-referential tables
-- and Directed-Acyclic-Graphs.
--
-- ## Alternative pretty printers
--
-- `pretty` is large, slow, and requires the debug library to work. It's not
-- designed for serialization purposes, nor is it concerned with offering the same
-- level of customization as other libraries do.
--
-- If you want a sleek, fast, customizable or embeddable library, there are
-- thankfully other options.
--
-- - [inspect.lua](github.com/kikito/inspect.lua): One of the classic debugging
-- pretty printers.
-- - [pprint.lua](github.com/jagt/pprint.lua): Reimplementation of `inspect.lua`
-- - [serpent](github.com/pkulchenko/serpent): Advanced and fast pretty printer.
-- - [pluto](lua-users.org/wiki/PlutoLibrary): Can serialize arbitrary parts of
-- Lua, including functions, upvalues, and proper lexical scoping. Not written
-- in native Lua.
-- - [binser](github.com/bakpakin/binser): Library for special purpose
-- serialization.
--
-- Even more are available at [the lua-users wiki](lua-users.org/wiki/TableSerialization).
--
-- ## Thoughts on displaying tables in an intuitive way.
--
-- Lua's table data-structure is likely to be the most concise data structure ever
-- invented. (If not, please send me a link!) Lists, maps, objects, classes,
-- proxies, etc. This obviously brings about it some difficulty when attempting to
-- represent these tables. What do we want to highlight, and what do we choose to
-- avoid?
--
-- One notable issue is whether to show every key that a table answers (to lift
-- some Smalltalk terms) to, or to just display those it contains. That is, do we
-- think about `__index` in the table's metatable and what it returns, or do we
-- ignore `__index`? For cases where `__index` is a function, we cannot say
-- anything about the keys that the table answers to. If `__index` is a table, we
-- have a better idea, but it would be cluttered to display both types of keys side
-- by side.
--
-- 1. Native representation: Lua's native representation includes the type and
-- address of the table. It allows for distinguishing between unique tables,
-- but won't tell us anything about the contents.
-- 2. Omission: By representing tables as the pseudo-parsable `{...}`, it's
-- clear we are talking about a table. We disregard the ability to
-- distinguish between tables.
-- 2A. If the table is empty, we could represent it as `{}`. But what if the table
-- has a metatable with `__index` defined? We could continue to represent it as
-- `{}`, but `{...}` would be more "honest".
-- 3. Single-line: TODO
-- 4. Multi-line: TODO
-- 5. Columns: For some highly-regular structures, like lists of short strings,
-- giving each string it's own line would be too long, but formatting them as a
-- single-line list would be too cluttered. Thus we can take inspiration from
-- the classic `ls` unix tool, and place the output into columns, to help guide
-- the eyes.
-- 6. Tabular: Other structures are formatted like actual tables of data, e.g. a
-- sequence of tuples, like one would see in an SQL database. For these
-- structures it's an obvious choice to align them based on the keys.
-- 7. Pseudo-Tabular: Some structures are almost tabular, e.g. they are sequences
-- of tuples, but some of the tuples differ in their structure. For these
-- structures it's still useful to tabulate the keys that all tuples share. To
-- do this we should sort the key order descending by the number of tuples with
-- the key.
-- But what do we do about the the outlier keys? We can either justify the
-- entire table, and give specific spots for the outlier keys, thereby
-- significantly increasing the size of the table, or we can leave the table
-- unjustified, abandoning it's eye-guiding attributes.
-- 8. Special cases: (Array-tree, Table-Tree, Linked-List, Predictive Sequences) TODO
--[[--
# Pretty
`pretty` is an advanced pretty printer for [Lua](https://lua.org). It's primarily a
debugging tool, aiming for human readability, by detecting pattern in the input
data, and creating an output string utilizing and highlighting those patterns.
## Code Example
Setup is simple, use `pretty = require 'pretty'`, and you're good to go.
```lua
$ print(pretty( { 1, 2, 3 } ))
{ 1, 2, 3 }
> print(pretty( { hello = 'world', num = 42 } ))
{
num = 42
hello = 'world'
}
> print(pretty( { abs = math.abs, max = math.max, some = function() end } ))
{
abs = builtin function (x) ... end
max = builtin function (x, ...) ... end
some = function () ... end
}
> print(pretty( math.abs ))
builtin function (x)
-- math.abs
-- Returns the absolute value of x
...
end
```
## Motivation
This project is the outcome of my frustration with existing pretty printers, and
a desire to expand upon the pretty printer I developed for
[Xenoterm](https://gitfub.space/takunomi/Xenoterm). The original Xenoterm pretty
printer was much simpler than `pretty` - and the current is even simpler - but
the enhancements I make, when compared to other pretty printers, inspired me to
create `pretty`.
`pretty` sorts it's priorities like so:
1. Human readability.
2. Lua-compatible output.
3. Customization.
I'd rather have good defaults than provide a ton of customization options. If an
structure avoids easy representation in Lua, I'd rather extend the syntax, than
lose the info.
Another aspect where `pretty` shines is in exploratory programming, when
attempting to avoid reliance on outside documentation. The amount of information
`pretty` exposes varies by the data you are inspecting. If you're inspecting
a list of functions, their function signatures are visible, but if you're
inspecting a single function, documentation and source location may appear if
available.
## Features
- Written in good-old pure-blood Lua, with support for PUC Lua 5.0+ and LuaJIT 2.0+.
- Redefining what it means to be "human readable":
* Is multi-line centric, to aid readability.
* Indention and alignment of keys-value pairs.
* Keys-value pairs are
[alpha-numerically](http://www.davekoelle.com/alphanum.html) sorted by key
type and thereafter alphabetically.
* The format and structure of output changes depending upon the input. Maps
appear differently to deeply nested tables to long sequences with short
strings to short lists.
* Uses the standard `debug` library to gain information about functions and
other advanced structures.
## Installation
`pretty` is loadable directly with `require`. Either clone or download this
repository. Where you place it, depends upon what you want to do:
1. **You want `pretty` in a specific project**: Place the `pretty` folder
somewhere in your project, and `require` it from one of your project files.
2. **You want `pretty` on your system**: Place the `pretty` folder such that
it's visible from your Lua-path. On my system this might be
`/usr/local/share/lua/5.1/`. Now you can `require` it from anywhere.
## API Documentation
`pretty` exposes a single function, the `pretty` function itself. It's function
signature is `pretty(value, options)`. `value` can be any Lua value. `options`
must be a table.
### List of options
`pretty` is sure to complain if you give it an unknown option, or if you give an
option a bad value.
- `indent: string`: The string to indent with. Four spaces by default.
## TODO
Tasks to be done before `pretty` can be called version 1.0.0, in order of
priority:
- [ ] Add dedicated unicode submodule, to handle some minor alignment and
character escaping issues. `pretty` should escape all malformed unicode
sequences.
- [ ] Align numbers towards right for tabular views.
- [ ] Add support for `setmetatable`, and exploring values in metatables.
- [ ] Provide nice formatting for `cdata` datatype in LuaJIT.
- [ ] Find a better name than `pretty`.
- [ ] Enhance internal structure some amount. See `TODO` markers in files.
It would be nice to have the following, but these are secondary:
- [ ] Add option for colored output. Primarily syntax highlighting, but also
[BlueJ-style](www.bluej.org/about.html) scope highlighting, with some faint
background colors.
- [ ] Expand on the comment output in output, for `__tostring` methods, and
global namespaces like `io` or `math`.
- [ ] Fit output within a predefined width limit. Default to 80.
- [ ] Look into tool for understanding complex structures with recursive
definitions. Whatever modes are thought up, they should be automatic modes, not
an options. Should at least include modes for self-referential tables and
Directed-Acyclic-Graphs.
## Alternative pretty printers
`pretty` is large, slow, and requires the debug library to work. It's not
designed for serialization purposes, nor is it concerned with offering the same
level of customization as other libraries do.
If you want a sleek, fast, customizable or embeddable library, there are
thankfully other options.
- [inspect.lua](github.com/kikito/inspect.lua): One of the classic debugging pretty printers.
- [pprint.lua](github.com/jagt/pprint.lua): Reimplementation of `inspect.lua`
- [serpent](github.com/pkulchenko/serpent): Advanced and fast pretty printer.
- [pluto](lua-users.org/wiki/PlutoLibrary): Can serialize arbitrary parts of
Lua, including functions, upvalues, and proper lexical scoping. Not written in
native Lua.
- [binser](github.com/bakpakin/binser): Library for special purpose serialization.
Even more are available at [the lua-users wiki](lua-users.org/wiki/TableSerialization).
## Thoughts on displaying tables in an intuitive way.
Lua's table data-structure is likely to be the most concise data structure ever
invented. (If not, please send me a link!) Lists, maps, objects, classes,
proxies, etc. This obviously brings about it some difficulty when attempting to
represent these tables. What do we want to highlight, and what do we choose to
avoid?
One notable issue is whether to show every key that a table answers (to lift
some Smalltalk terms) to, or to just display those it contains. That is, do we
think about `__index` in the table's metatable and what it returns, or do we
ignore `__index`? For cases where `__index` is a function, we cannot say
anything about the keys that the table answers to. If `__index` is a table, we
have a better idea, but it would be cluttered to display both types of keys side
by side.
1. Native representation: Lua's native representation includes the type and
address of the table. It allows for distinguishing between unique tables,
but won't tell us anything about the contents.
2. Omission: By representing tables as the pseudo-parsable `{...}`, it's
clear we are talking about a table. We disregard the ability to
distinguish between tables.
2. If the table is empty, we could represent it as `{}`. But what if the table
has a metatable with `__index` defined? We could continue to represent it as
`{}`, but `{...}` would be more "honest".
3. Single-line: TODO
4. Multi-line: TODO
5. Columns: For some highly-regular structures, like lists of short strings,
giving each string it's own line would be too long, but formatting them as a
single-line list would be too cluttered. Thus we can take inspiration from
the classic `ls` unix tool, and place the output into columns, to help guide
the eyes.
6. Tabular: Other structures are formatted like actual tables of data, e.g. a
sequence of tuples, like one would see in an SQL database. For these
structures it's an obvious choice to align them based on the keys.
7. Pseudo-Tabular: Some structures are almost tabular, e.g. they are sequences
of tuples, but some of the tuples differ in their structure. For these
structures it's still useful to tabulate the keys that all tuples share. To
do this we should sort the key order descending by the number of tuples with
the key.
But what do we do about the the outlier keys? We can either justify the
entire table, and give specific spots for the outlier keys, thereby
significantly increasing the size of the table, or we can leave the table
unjustified, abandoning it's eye-guiding attributes.
8. Special cases: (Array-tree, Table-Tree, Linked-List, Predictive Sequences) TODO
--]]
--------------------------------------------------------------------------------
-- Import files
local import
do
local thispath = ... and select('1', ...):match('.+%.') or ''
import = function (name, ignore_failure) return require(thispath..name) end
local this_path = ... and select('1', ...):match('.+%.') or ''
import = function (name, ignore_failure) return require(this_path..name) end
end
--------------------------------------------------------------------------------
@ -421,10 +422,10 @@ local function attempt_to_align_into_columns (l, start_i, stop_i, nr_items_pr_ro
assert(type(stop_i) == 'number')
assert(type(nr_items_pr_row) == 'number')
local column = {}
local column = {}
---
local start_of_item_i, item_nr = nil, 0
for i = start_i, stop_i do
for i = start_i, stop_i do
if type(l[i]) == 'table' and (l[i][1] == 'indent' or l[i][1] == 'seperator' or l[i][1] == 'unindent') then
if start_of_item_i then
local width_of_item = width_of_strings_in_l(l, start_of_item_i, i-1)
@ -433,12 +434,12 @@ local function attempt_to_align_into_columns (l, start_i, stop_i, nr_items_pr_ro
end
start_of_item_i, item_nr = i + 1, item_nr + 1
end
end
end
---
local width = nr_items_pr_row * 2 - 1 -- FIXME: Magic numbers: 2 = #', ', 1 = #' '
for i = 1, #column do width = width + column[i] end
--
return width, column
return width, column
end
local function align_into_columns (l, start_i, stop_i)
@ -448,8 +449,8 @@ local function align_into_columns (l, start_i, stop_i)
local start_i, stop_i = start_i or 1, stop_i or #l
assert(type(start_i) == 'number')
assert(type(stop_i) == 'number')
assert(type(start_i) == 'number')
assert(type(stop_i) == 'number')
insert_alignment_estimations(l, start_i, stop_i)
@ -480,7 +481,7 @@ local function align_into_columns (l, start_i, stop_i)
-- Fit into columns.
local start_of_item_i, item_nr = nil, 0
for i = start_i, stop_i do
for i = start_i, stop_i do
if type(l[i]) ~= 'table' then
-- Do nothing
elseif (l[i][1] == 'indent' or l[i][1] == 'seperator' or l[i][1] == 'unindent') then
@ -493,47 +494,47 @@ local function align_into_columns (l, start_i, stop_i)
end
start_of_item_i, item_nr = i + 1, item_nr + 1
end
end
end
end
local function align_into_tabular_style (l, start_i, stop_i)
-- Adds alignment after separators, to create nicely aligned tabular-format.
-- Adds alignment after separators, to create nicely aligned tabular-format.
-- Argument fixing and Error Checking
local start_i, stop_i = start_i or 1, stop_i or #l
local start_i, stop_i = start_i or 1, stop_i or #l
assert(type(l) == 'table')
assert(type(start_i) == 'number')
assert(type(stop_i) == 'number')
assert(type(l[start_i]) == 'table' and l[start_i][1] == 'indent')
assert(type(l[stop_i]) == 'table' and l[stop_i][1] == 'unindent')
assert(type(l) == 'table')
assert(type(start_i) == 'number')
assert(type(stop_i) == 'number')
assert(type(l[start_i]) == 'table' and l[start_i][1] == 'indent')
assert(type(l[stop_i]) == 'table' and l[stop_i][1] == 'unindent')
-- Calculate where to insert new alignment.
local indent, key_nr, index_of_last_meta, insert_later = 0, 0, 1, {}
for i = start_i + 1, stop_i - 1 do
if type(l[i]) ~= 'table' then
-- Do nothing
elseif l[i][1] == 'indent' then
indent = indent + 1
if indent == 1 then key_nr = 1 end
index_of_last_meta = i
elseif l[i][1] == 'unindent' then
insert_later[#insert_later+1] = {'align', 'end_subtable_'..key_nr, width_of_strings_in_l(l, index_of_last_meta+1, i), i}
index_of_last_meta, key_nr = i, key_nr + 1
indent = indent - 1
elseif l[i][1] == 'seperator' and indent ~= 0 then
insert_later[#insert_later+1] = {'align', 'key_'..key_nr, width_of_strings_in_l(l, index_of_last_meta+1, i), i+1}
index_of_last_meta, key_nr = i, key_nr + 1
end
-- Calculate where to insert new alignment.
local indent, key_nr, index_of_last_meta, insert_later = 0, 0, 1, {}
for i = start_i + 1, stop_i - 1 do
if type(l[i]) ~= 'table' then
-- Do nothing
elseif l[i][1] == 'indent' then
indent = indent + 1
if indent == 1 then key_nr = 1 end
index_of_last_meta = i
elseif l[i][1] == 'unindent' then
insert_later[#insert_later+1] = {'align', 'end_subtable_'..key_nr, width_of_strings_in_l(l, index_of_last_meta+1, i), i}
index_of_last_meta, key_nr = i, key_nr + 1
indent = indent - 1
elseif l[i][1] == 'seperator' and indent ~= 0 then
insert_later[#insert_later+1] = {'align', 'key_'..key_nr, width_of_strings_in_l(l, index_of_last_meta+1, i), i+1}
index_of_last_meta, key_nr = i, key_nr + 1
end
end
-- Insert new alignment.
for i = #insert_later, 1, -1 do
local dat = insert_later[i]
table.insert(l, dat[#dat], dat)
dat[#dat] = nil
end
-- Fix that alignemnt
return fix_alignment(l, start_i)
-- Insert new alignment.
for i = #insert_later, 1, -1 do
local dat = insert_later[i]
table.insert(l, dat[#dat], dat)
dat[#dat] = nil
end
-- Fix that alignemnt
return fix_alignment(l, start_i)
end
local function fix_seperator_info (l, indent_char)
@ -562,9 +563,9 @@ end
--------------------------------------------------------------------------------
local analyze_structure = import 'analyze_structure'
local TABLE_TYPE = import 'common' . TABLE_TYPE
local DISPLAY = import 'common' . DISPLAY
local analyze_structure = import 'analyze_structure'
local TABLE_TYPE = import 'common' . TABLE_TYPE
local DISPLAY = import 'common' . DISPLAY
--------------------------------------------------------------------------------
-- Key-value pair formatting.
@ -657,8 +658,8 @@ local function format_table (t, display, l, format_value)
-- NOTE: Currently we only allow leaf-nodes to format into columns, due
-- to issues with table alignment.
align_into_columns(l, start_of_table_i)
elseif table_info.is_tabular then
align_into_tabular_style(l, start_of_table_i, #l)
elseif table_info.is_tabular then
align_into_tabular_style(l, start_of_table_i, #l)
else
-- Is long table: Fix whitespace alignment
fix_alignment(l, start_of_table_i)