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|
#! /usr/bin/lua
-- $NetBSD: fmt-list,v 1.6 2022/09/08 05:05:08 rillig Exp $
--[[
Align the lines of a file list so that all lines from the same directory
have the other fields at the same indentation.
Sort the lines and remove duplicate lines.
usage: ./fmt-list [-n] */*/{mi,ad.*,md.*}
]]
local function test(func)
func()
end
local function assert_equals(got, expected)
if got ~= expected then
assert(false, ("got %q, expected %q"):format(got, expected))
end
end
-- Calculate the width of the given string on the screen, assuming that
-- the tab width is 8 and that the string starts at a tabstop.
local function tabwidth(str)
local width = 0
for i = 1, #str do
if str:sub(i, i) == "\t" then
width = width // 8 * 8 + 8
else
width = width + 1
end
end
return width
end
test(function()
assert_equals(tabwidth(""), 0)
assert_equals(tabwidth("1234"), 4)
assert_equals(tabwidth("\t"), 8)
assert_equals(tabwidth("1234567\t"), 8)
assert_equals(tabwidth("\t1234\t"), 16)
assert_equals(tabwidth("\t1234\t1"), 17)
end)
-- Calculate the tab characters that are necessary to set the width
-- of the string to the desired width.
local function tabs(str, width)
local strwidth = tabwidth(str)
local tabs = ("\t"):rep((width - strwidth + 7) // 8)
if tabs == "" then
error(("%q\t%d\t%d"):format(str, strwidth, width))
end
assert(tabs ~= "")
return tabs
end
test(function()
assert_equals(tabs("", 8), "\t")
assert_equals(tabs("1234567", 8), "\t")
assert_equals(tabs("", 64), "\t\t\t\t\t\t\t\t")
end)
-- Group the items by a key and then execute the action on each of the
-- groups.
local function foreach_group(items, get_key, action)
local key
local group = {}
for _, item in ipairs(items) do
local item_key = assert(get_key(item))
if item_key ~= key then
if #group > 0 then action(group, key) end
key = item_key
group = {}
end
table.insert(group, item)
end
if #group > 0 then action(group, key) end
end
test(function()
local items = {
{"prime", 2},
{"prime", 3},
{"not prime", 4},
{"prime", 5},
{"prime", 7}
}
local result = ""
foreach_group(
items,
function(item) return item[1] end,
function(group, key)
result = result .. ("%d %s\n"):format(#group, key)
end)
assert_equals(result, "2 prime\n1 not prime\n2 prime\n")
end)
-- Parse a line from a file list and split it into its meaningful parts.
local function parse_entry(line)
local category_align, prefix, fullname, flags_align, category, flags =
line:match("^(([#%-]?)(%.%S*)%s+)((%S+)%s+)(%S+)$")
if fullname == nil then
category_align, prefix, fullname, category =
line:match("^(([#%-]?)(%.%S*)%s+)(%S+)$")
end
if fullname == nil then
prefix, fullname = line:match("^(%-)(%.%S*)$")
end
if fullname == nil then
return
end
local dirname, basename = fullname:match("^(.+)/([^/]+)$")
if dirname == nil then
dirname, basename = "", fullname
end
local category_col, flags_col
if category_align ~= nil then
category_col = tabwidth(category_align)
end
if flags_align ~= nil then
flags_col = tabwidth(flags_align)
end
return {
prefix = prefix,
fullname = fullname,
dirname = dirname,
basename = basename,
category_col = category_col,
category = category,
flags_col = flags_col,
flags = flags
}
end
test(function()
local entry = parse_entry("./dirname/filename\t\t\tcategory\tflags")
assert_equals(entry.prefix, "")
assert_equals(entry.fullname, "./dirname/filename")
assert_equals(entry.dirname, "./dirname")
assert_equals(entry.basename, "filename")
assert_equals(entry.category_col, 40)
assert_equals(entry.category, "category")
assert_equals(entry.flags_col, 16)
assert_equals(entry.flags, "flags")
entry = parse_entry("#./dirname/filename\tcat\tflags")
assert_equals(entry.prefix, "#")
assert_equals(entry.fullname, "./dirname/filename")
assert_equals(entry.dirname, "./dirname")
assert_equals(entry.basename, "filename")
assert_equals(entry.category_col, 24)
assert_equals(entry.category, "cat")
assert_equals(entry.flags_col, 8)
assert_equals(entry.flags, "flags")
end)
-- Return the smaller of the given values, ignoring nil.
local function min(curr, value)
if curr == nil or (value ~= nil and value < curr) then
return value
end
return curr
end
test(function()
assert_equals(min(nil, nil), nil)
assert_equals(min(0, nil), 0)
assert_equals(min(nil, 0), 0)
assert_equals(min(0, 0), 0)
assert_equals(min(1, -1), -1)
assert_equals(min(-1, 1), -1)
end)
-- Return the larger of the given values, ignoring nil.
local function max(curr, value)
if curr == nil or (value ~= nil and value > curr) then
return value
end
return curr
end
test(function()
assert_equals(max(nil, nil), nil)
assert_equals(max(0, nil), 0)
assert_equals(max(nil, 0), 0)
assert_equals(max(0, 0), 0)
assert_equals(max(1, -1), 1)
assert_equals(max(-1, 1), 1)
end)
-- Calculate the column on which the field should be aligned.
local function column(entries, get_width_before, colname)
local function nexttab(col)
return col // 8 * 8 + 8
end
local currmin, currmax, required
for _, entry in ipairs(entries) do
local width = get_width_before(entry)
if width ~= nil then
required = max(required, width)
local col = entry[colname]
currmin = min(currmin, col)
currmax = max(currmax, col)
end
end
if currmin == currmax then
return currmin, "aligned"
end
return nexttab(required), "unaligned"
end
test(function()
local function width_before_category(entry)
return tabwidth(entry.prefix .. entry.fullname)
end
local function width_before_flags(entry)
return tabwidth(entry.category)
end
-- The entries are nicely aligned, therefore there is no need to change
-- anything.
local entries = {
parse_entry("./file1\tcategory"),
parse_entry("./file2\tcategory")
}
assert_equals(entries[2].category_col, 8)
assert_equals(width_before_category(entries[2]), 7)
assert_equals(column(entries, width_before_category, "category_col"), 8)
-- The entries are currently not aligned, therefore they are aligned
-- to the minimum required column.
entries = {
parse_entry("./file1\tcategory"),
parse_entry("./directory/file2\tcategory"),
}
assert_equals(entries[2].category_col, 24)
assert_equals(column(entries, width_before_category, "category_col"), 24)
-- The entries are already aligned, therefore the current alignment is
-- preserved, even though it is more than the minimum required alignment
-- of 8. There are probably reasons for the large indentation.
entries = {
parse_entry("./file1\t\t\tcategory"),
parse_entry("./file2\t\t\tcategory")
}
assert_equals(column(entries, width_before_category, "category_col"), 24)
-- The flags are already aligned, 4 tabs to the right of the category.
-- There is no reason to change anything here.
entries = {
parse_entry("./file1\tcategory\t\t\tflags"),
parse_entry("./file2\tcategory"),
parse_entry("./file3\tcat\t\t\t\tflags")
}
assert_equals(column(entries, width_before_flags, "flags_col"), 32)
end)
-- Amend the entries by the tabs used for alignment.
local function add_tabs(entries)
local function width_before_category(entry)
return tabwidth(entry.prefix .. entry.fullname)
end
local function width_before_flags(entry)
if entry.flags ~= nil then
return tabwidth(entry.category)
end
end
local category_col, category_aligned =
column(entries, width_before_category, "category_col")
local flags_col = column(entries, width_before_flags, "flags_col")
-- To avoid horizontal jumps for the category column, the minimum column is
-- set to 56. This way, the third column is usually set to 72, which is
-- still visible on an 80-column screen.
if category_aligned == "unaligned" then
category_col = max(category_col, 56)
end
for _, entry in ipairs(entries) do
local prefix = entry.prefix
local fullname = entry.fullname
local category = entry.category
local flags = entry.flags
if category ~= nil then
entry.category_tabs = tabs(prefix .. fullname, category_col)
if flags ~= nil then
entry.flags_tabs = tabs(category, flags_col)
end
end
end
end
test(function()
local entries = {
parse_entry("./file1\t\t\t\tcategory\t\tflags"),
parse_entry("./file2\t\t\t\tcategory\t\tflags"),
parse_entry("./file3\t\t\tcategory\t\tflags")
}
add_tabs(entries)
assert_equals(entries[1].category_tabs, "\t\t\t\t\t\t\t")
assert_equals(entries[2].category_tabs, "\t\t\t\t\t\t\t")
assert_equals(entries[3].category_tabs, "\t\t\t\t\t\t\t")
assert_equals(entries[1].flags_tabs, "\t\t")
assert_equals(entries[2].flags_tabs, "\t\t")
assert_equals(entries[3].flags_tabs, "\t\t")
end)
-- Normalize the alignment of the fields of the entries.
local function normalize(entries)
local function less(a, b)
if a.fullname ~= b.fullname then
-- To sort by directory first, comment out the following line.
return a.fullname < b.fullname
end
if a.dirname ~= b.dirname then
return a.dirname < b.dirname
end
if a.basename ~= b.basename then
return a.basename < b.basename
end
if a.category ~= nil and b.category ~= nil and a.category ~= b.category then
return a.category < b.category
end
return a.flags ~= nil and b.flags ~= nil and a.flags < b.flags
end
table.sort(entries, less)
local function by_dirname(entry)
return entry.dirname
end
foreach_group(entries, by_dirname, add_tabs)
end
-- Read a file list completely into memory.
local function read_list(fname)
local head = {}
local entries = {}
local errors = {}
local f = assert(io.open(fname, "r"))
local lineno = 0
for line in f:lines() do
lineno = lineno + 1
local entry = parse_entry(line)
if entry ~= nil then
table.insert(entries, entry)
elseif line:match("^#") then
table.insert(head, line)
else
local msg = ("%s:%d: unknown line format %q"):format(fname, lineno, line)
table.insert(errors, msg)
end
end
f:close()
return head, entries, errors
end
-- Write the normalized list file back to disk.
--
-- Duplicate lines are skipped. This allows to append arbitrary lines to
-- the end of the file and have them cleaned up automatically.
local function write_list(fname, head, entries)
local f = assert(io.open(fname, "w"))
for _, line in ipairs(head) do
f:write(line, "\n")
end
local prev_line = ""
for _, entry in ipairs(entries) do
local line = entry.prefix .. entry.fullname
if entry.category ~= nil then
line = line .. entry.category_tabs .. entry.category
end
if entry.flags ~= nil then
line = line .. entry.flags_tabs .. entry.flags
end
if line ~= prev_line then
prev_line = line
f:write(line, "\n")
else
--print(("%s: duplicate entry: %s"):format(fname, line))
end
end
f:close()
end
-- Load a file list, normalize it and write it back to disk.
local function format_list(fname, write_back)
local head, entries, errors = read_list(fname)
if #errors > 0 then
for _, err in ipairs(errors) do
print(err)
end
return false
end
normalize(entries)
if write_back then
write_list(fname, head, entries)
end
return true
end
local function main(arg)
local seen_error = false
local write_back = true
for _, fname in ipairs(arg) do
if fname == "-n" then
write_back = false
else
if not format_list(fname, write_back) then
seen_error = true
end
end
end
return not seen_error
end
os.exit(main(arg))
|