3 files changed, 55 insertions(+), 80 deletions(-)

M day05/day05a.lua
M day05/day05b.lua
A day05/parse.lua

@@ 6,45 6,7 @@
 -- Distributed under terms of the MIT license.
 --
 
--- Contains the lines of input describing the initial contents of the
--- stacks, to be parsed *after* knowing how many stacks are there.
-local stacks_lines = {}
-
-while true do
-   local line = io.read()
-   if line == "" then
-      break
-   end
-
-   stacks_lines[#stacks_lines+1] = line
-end
-
--- Last read line contains the numbered stacks, the last number will be
--- the same as the amount of stacks being handled. Also remove that last
--- line from the pending-to-parse input.
-local nstacks = 0
-for n in stacks_lines[#stacks_lines]:gmatch("%s*(%d+)%s*") do
-   nstacks = tonumber(n)
-end
-table.remove(stacks_lines)
-
--- Table where each element is a stack, initially empty.
-local stacks = {}
-for i = 1, nstacks do
-   stacks[i] = {}
-end
-
--- Parse the stack contents lines backwards, so we get to pile up the
--- items from the bottom upwards. We can iterate over each found "["
--- character, and from their position in the line determine in which
--- stack they are: positions for the opening bracket are always multiples
--- of four.
-for i = #stacks_lines, 1, -1 do
-   for bracketpos, label in stacks_lines[i]:gmatch("()%[(%a+)%]") do
-      local stacknum = (bracketpos // 4) + 1
-      table.insert(stacks[stacknum], label)
-   end
-end
+local stacks = require "parse" ()
 
 for line in io.lines() do
    local _, _, n, from, to = line:find("move (%d+) from (%d+) to (%d+)")


@@ 55,7 17,7 @@ for line in io.lines() do
 end
 
 local result = {}
-for i = 1, nstacks do
+for i = 1, #stacks do
    local thisstack = stacks[i]
    if #thisstack > 0 then
       result[#result+1] = thisstack[#thisstack]

@@ 6,45 6,7 @@
 -- Distributed under terms of the MIT license.
 --
 
--- Contains the lines of input describing the initial contents of the
--- stacks, to be parsed *after* knowing how many stacks are there.
-local stacks_lines = {}
-
-while true do
-   local line = io.read()
-   if line == "" then
-      break
-   end
-
-   stacks_lines[#stacks_lines+1] = line
-end
-
--- Last read line contains the numbered stacks, the last number will be
--- the same as the amount of stacks being handled. Also remove that last
--- line from the pending-to-parse input.
-local nstacks = 0
-for n in stacks_lines[#stacks_lines]:gmatch("%s*(%d+)%s*") do
-   nstacks = tonumber(n)
-end
-table.remove(stacks_lines)
-
--- Table where each element is a stack, initially empty.
-local stacks = {}
-for i = 1, nstacks do
-   stacks[i] = {}
-end
-
--- Parse the stack contents lines backwards, so we get to pile up the
--- items from the bottom upwards. We can iterate over each found "["
--- character, and from their position in the line determine in which
--- stack they are: positions for the opening bracket are always multiples
--- of four.
-for i = #stacks_lines, 1, -1 do
-   for bracketpos, label in stacks_lines[i]:gmatch("()%[(%a+)%]") do
-      local stacknum = (bracketpos // 4) + 1
-      table.insert(stacks[stacknum], label)
-   end
-end
+local stacks = require "parse" ()
 
 for line in io.lines() do
    local _, _, n, from, to = line:find("move (%d+) from (%d+) to (%d+)")


@@ 62,7 24,7 @@ for line in io.lines() do
 end
 
 local result = {}
-for i = 1, nstacks do
+for i = 1, #stacks do
    local thisstack = stacks[i]
    if #thisstack > 0 then
       result[#result+1] = thisstack[#thisstack]

@@ 0,0 1,51 @@
+#! /usr/bin/env lua
+--
+-- common.lua
+-- Copyright (C) 2022 Adrian Perez de Castro <aperez@igalia.com>
+--
+-- Distributed under terms of the MIT license.
+--
+
+return function ()
+   -- Contains the lines of input describing the initial contents of the
+   -- stacks, to be parsed *after* knowing how many stacks are there.
+   local stacks_lines = {}
+
+   while true do
+      local line = io.read()
+      if line == "" then
+         break
+      end
+
+      stacks_lines[#stacks_lines+1] = line
+   end
+
+   -- Last read line contains the numbered stacks, the last number will be
+   -- the same as the amount of stacks being handled. Also remove that last
+   -- line from the pending-to-parse input.
+   local nstacks = 0
+   for n in stacks_lines[#stacks_lines]:gmatch("%s*(%d+)%s*") do
+      nstacks = tonumber(n)
+   end
+   table.remove(stacks_lines)
+
+   -- Table where each element is a stack, initially empty.
+   local stacks = {}
+   for i = 1, nstacks do
+      stacks[i] = {}
+   end
+
+   -- Parse the stack contents lines backwards, so we get to pile up the
+   -- items from the bottom upwards. We can iterate over each found "["
+   -- character, and from their position in the line determine in which
+   -- stack they are: positions for the opening bracket are always multiples
+   -- of four.
+   for i = #stacks_lines, 1, -1 do
+      for bracketpos, label in stacks_lines[i]:gmatch("()%[(%a+)%]") do
+         local stacknum = (bracketpos // 4) + 1
+         table.insert(stacks[stacknum], label)
+      end
+   end
+
+   return stacks
+end