From e6683932e88705a494ce82d9e8c306248d6f2d1f Mon Sep 17 00:00:00 2001
From: Daniel Flanagan <daniel@lyte.dev>
Date: Fri, 4 Dec 2020 11:02:05 -0600
Subject: [PATCH] More cleanup, stick precompiled regexes in a table

---
 2020/src/aoc2020.nim |  4 ++--
 2020/src/day2.nim    | 20 ++++++--------------
 2020/src/day4.nim    | 16 ++++++++++++----
 3 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/2020/src/aoc2020.nim b/2020/src/aoc2020.nim
index df5140a..720eab8 100644
--- a/2020/src/aoc2020.nim
+++ b/2020/src/aoc2020.nim
@@ -8,5 +8,5 @@ proc solve_for_day(n: int) {.used.} =
   echo solvers[n]()
 
 when isMainModule:
-  # solve_all()
-  solve_for_day(4)
+  solve_all()
+  # solve_for_day(4)
diff --git a/2020/src/day2.nim b/2020/src/day2.nim
index d62ae7d..df05993 100644
--- a/2020/src/day2.nim
+++ b/2020/src/day2.nim
@@ -1,4 +1,4 @@
-import streams, strutils, re
+import streams, strutils, re, sequtils
 
 type PasswordPolicy = tuple[min: int, max: int, keyChar: char]
 
@@ -8,20 +8,12 @@ proc parsePasswordLine(str: string): (PasswordPolicy, string) =
   if match(str, parsePasswordLineRe, matches):
     return ((min: parseInt(matches[0]), max: parseInt(matches[1]), keyChar: matches[2][0]), matches[3])
 
-iterator asPasswordPolicies(s: Stream): (PasswordPolicy, string) =
-  for line in s.lines(): yield parsePasswordLine line
-
-proc isValidPassword(str: string, pp: PasswordPolicy): bool =
-  let count = str.count pp.keyChar
-  (pp.min <= count) and (count <= pp.max)
-
-proc isValidPasswordPart2(str: string, pp: PasswordPolicy): bool =
-  (str[pp.min - 1] == pp.keyChar) xor (pp.keyChar == str[pp.max - 1])
+proc asPasswordPolicies(s: Stream): seq[(PasswordPolicy, string)] =
+  toSeq(s.lines()).mapIt(it.parsePasswordLine)
 
 proc part1*(s: Stream): int =
-  for (pp, pw) in s.asPasswordPolicies:
-    if isValidPassword(pw, pp): inc result
+  s.asPasswordPolicies.countIt(it[1].count(it[0].keyChar) in it[0].min..it[0].max)
 
 proc part2*(s: Stream): int =
-  for (pp, pw) in s.asPasswordPolicies:
-    if isValidPasswordPart2(pw, pp): inc result
+  s.asPasswordPolicies.countIt(
+    (it[1][it[0].min - 1] == it[0].keyChar) xor (it[0].keyChar == it[1][it[0].max - 1]))
diff --git a/2020/src/day4.nim b/2020/src/day4.nim
index ec45a33..46b36ba 100644
--- a/2020/src/day4.nim
+++ b/2020/src/day4.nim
@@ -1,15 +1,23 @@
 import streams, strutils, sets, sequtils, sugar, re, tables
 
+let regexes = toTable({
+  "hcl": re"^#[0-9a-f]{6}$",
+  "ecl": re"^(amb|blu|brn|gry|grn|hzl|oth)$",
+  "pid": re"^\d{9}$",
+  "hgt": re"^\d+(cm|in)$",
+  "nondec": re"[^0-9]",
+})
+
 let validators = toTable({
-  "hcl": (v: string) => v.match re"^#[0-9a-f]{6}$",
-  "ecl": (v: string) => v.match re"^(amb|blu|brn|gry|grn|hzl|oth)$",
-  "pid": (v: string) => v.match re"^\d{9}$",
+  "hcl": (v: string) => v.match regexes["hcl"],
+  "ecl": (v: string) => v.match regexes["ecl"],
+  "pid": (v: string) => v.match regexes["pid"],
   "byr": (v: string) => parseInt(v) in 1920..2002,
   "iyr": (v: string) => parseInt(v) in 2010..2020,
   "eyr": (v: string) => parseInt(v) in 2020..2030,
   "hgt": proc (v: string): bool =
     let (mn, mx) = if v.endsWith("cm"): (150, 193) else: (59, 76)
-    v.match(re"^\d+(cm|in)$") and v.replace(re"[^0-9]").parseInt in mn..mx,
+    v.match(regexes["hgt"]) and v.replace(regexes["nondec"]).parseInt in mn..mx,
   "cid": (v: string) => true,
 })