parse day 14 grid

haven't implemented the falling sand yet, but theres a cool expect test
that draws the grid

inputs/day14.tt

@@ -0,0 +1,148 @@
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+502,32 -> 507,32
+522,47 -> 522,43 -> 522,47 -> 524,47 -> 524,41 -> 524,47 -> 526,47 -> 526,39 -> 526,47 -> 528,47 -> 528,39 -> 528,47
+516,32 -> 521,32
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+512,30 -> 517,30
+522,47 -> 522,43 -> 522,47 -> 524,47 -> 524,41 -> 524,47 -> 526,47 -> 526,39 -> 526,47 -> 528,47 -> 528,39 -> 528,47
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+520,130 -> 520,133 -> 515,133 -> 515,138 -> 533,138 -> 533,133 -> 525,133 -> 525,130
+506,34 -> 511,34
+529,112 -> 529,116 -> 526,116 -> 526,122 -> 541,122 -> 541,116 -> 535,116 -> 535,112
+498,13 -> 498,15 -> 492,15 -> 492,23 -> 506,23 -> 506,15 -> 501,15 -> 501,13
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+523,63 -> 523,66 -> 515,66 -> 515,71 -> 529,71 -> 529,66 -> 528,66 -> 528,63
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+512,173 -> 517,173
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+498,13 -> 498,15 -> 492,15 -> 492,23 -> 506,23 -> 506,15 -> 501,15 -> 501,13
+545,94 -> 550,94
+539,100 -> 544,100
+522,47 -> 522,43 -> 522,47 -> 524,47 -> 524,41 -> 524,47 -> 526,47 -> 526,39 -> 526,47 -> 528,47 -> 528,39 -> 528,47
+529,112 -> 529,116 -> 526,116 -> 526,122 -> 541,122 -> 541,116 -> 535,116 -> 535,112
+553,100 -> 558,100
+501,170 -> 506,170
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+498,13 -> 498,15 -> 492,15 -> 492,23 -> 506,23 -> 506,15 -> 501,15 -> 501,13
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+498,13 -> 498,15 -> 492,15 -> 492,23 -> 506,23 -> 506,15 -> 501,15 -> 501,13
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+546,100 -> 551,100
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+542,97 -> 547,97
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+535,97 -> 540,97
+533,108 -> 533,109 -> 538,109 -> 538,108
+522,47 -> 522,43 -> 522,47 -> 524,47 -> 524,41 -> 524,47 -> 526,47 -> 526,39 -> 526,47 -> 528,47 -> 528,39 -> 528,47
+509,32 -> 514,32
+513,34 -> 518,34
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+520,130 -> 520,133 -> 515,133 -> 515,138 -> 533,138 -> 533,133 -> 525,133 -> 525,130
+507,164 -> 512,164
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+557,103 -> 562,103
+538,94 -> 543,94
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+520,130 -> 520,133 -> 515,133 -> 515,138 -> 533,138 -> 533,133 -> 525,133 -> 525,130
+520,130 -> 520,133 -> 515,133 -> 515,138 -> 533,138 -> 533,133 -> 525,133 -> 525,130
+498,13 -> 498,15 -> 492,15 -> 492,23 -> 506,23 -> 506,15 -> 501,15 -> 501,13
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+523,63 -> 523,66 -> 515,66 -> 515,71 -> 529,71 -> 529,66 -> 528,66 -> 528,63
+501,28 -> 506,28
+505,173 -> 510,173
+531,87 -> 531,88 -> 543,88
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+520,130 -> 520,133 -> 515,133 -> 515,138 -> 533,138 -> 533,133 -> 525,133 -> 525,130
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+524,126 -> 524,127 -> 528,127 -> 528,126
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+523,63 -> 523,66 -> 515,66 -> 515,71 -> 529,71 -> 529,66 -> 528,66 -> 528,63
+508,28 -> 513,28
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+523,63 -> 523,66 -> 515,66 -> 515,71 -> 529,71 -> 529,66 -> 528,66 -> 528,63
+511,167 -> 516,167
+549,97 -> 554,97
+541,91 -> 546,91
+522,47 -> 522,43 -> 522,47 -> 524,47 -> 524,41 -> 524,47 -> 526,47 -> 526,39 -> 526,47 -> 528,47 -> 528,39 -> 528,47
+522,47 -> 522,43 -> 522,47 -> 524,47 -> 524,41 -> 524,47 -> 526,47 -> 526,39 -> 526,47 -> 528,47 -> 528,39 -> 528,47
+520,34 -> 525,34
+522,47 -> 522,43 -> 522,47 -> 524,47 -> 524,41 -> 524,47 -> 526,47 -> 526,39 -> 526,47 -> 528,47 -> 528,39 -> 528,47
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+522,47 -> 522,43 -> 522,47 -> 524,47 -> 524,41 -> 524,47 -> 526,47 -> 526,39 -> 526,47 -> 528,47 -> 528,39 -> 528,47
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+505,30 -> 510,30
+543,103 -> 548,103
+510,146 -> 515,146
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+498,173 -> 503,173
+498,13 -> 498,15 -> 492,15 -> 492,23 -> 506,23 -> 506,15 -> 501,15 -> 501,13
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+523,63 -> 523,66 -> 515,66 -> 515,71 -> 529,71 -> 529,66 -> 528,66 -> 528,63
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+522,47 -> 522,43 -> 522,47 -> 524,47 -> 524,41 -> 524,47 -> 526,47 -> 526,39 -> 526,47 -> 528,47 -> 528,39 -> 528,47
+498,13 -> 498,15 -> 492,15 -> 492,23 -> 506,23 -> 506,15 -> 501,15 -> 501,13
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+533,108 -> 533,109 -> 538,109 -> 538,108
+517,146 -> 522,146
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+513,144 -> 518,144
+515,170 -> 520,170
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+520,130 -> 520,133 -> 515,133 -> 515,138 -> 533,138 -> 533,133 -> 525,133 -> 525,130
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+523,63 -> 523,66 -> 515,66 -> 515,71 -> 529,71 -> 529,66 -> 528,66 -> 528,63
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+519,173 -> 524,173
+532,100 -> 537,100
+524,126 -> 524,127 -> 528,127 -> 528,126
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+529,112 -> 529,116 -> 526,116 -> 526,122 -> 541,122 -> 541,116 -> 535,116 -> 535,112
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+521,148 -> 526,148
+504,167 -> 509,167
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+529,112 -> 529,116 -> 526,116 -> 526,122 -> 541,122 -> 541,116 -> 535,116 -> 535,112
+520,130 -> 520,133 -> 515,133 -> 515,138 -> 533,138 -> 533,133 -> 525,133 -> 525,130
+514,148 -> 519,148
+510,141 -> 515,141
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+533,108 -> 533,109 -> 538,109 -> 538,108
+524,126 -> 524,127 -> 528,127 -> 528,126
+550,103 -> 555,103
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+529,103 -> 534,103
+504,26 -> 509,26
+529,112 -> 529,116 -> 526,116 -> 526,122 -> 541,122 -> 541,116 -> 535,116 -> 535,112
+508,170 -> 513,170
+523,63 -> 523,66 -> 515,66 -> 515,71 -> 529,71 -> 529,66 -> 528,66 -> 528,63
+499,34 -> 504,34
+522,47 -> 522,43 -> 522,47 -> 524,47 -> 524,41 -> 524,47 -> 526,47 -> 526,39 -> 526,47 -> 528,47 -> 528,39 -> 528,47
+529,112 -> 529,116 -> 526,116 -> 526,122 -> 541,122 -> 541,116 -> 535,116 -> 535,112
+495,32 -> 500,32
+507,148 -> 512,148
+515,60 -> 515,52 -> 515,60 -> 517,60 -> 517,55 -> 517,60 -> 519,60 -> 519,50 -> 519,60 -> 521,60 -> 521,56 -> 521,60 -> 523,60 -> 523,53 -> 523,60 -> 525,60 -> 525,53 -> 525,60
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+531,87 -> 531,88 -> 543,88
+536,103 -> 541,103
+501,161 -> 501,152 -> 501,161 -> 503,161 -> 503,157 -> 503,161 -> 505,161 -> 505,155 -> 505,161 -> 507,161 -> 507,154 -> 507,161 -> 509,161 -> 509,155 -> 509,161
+522,84 -> 522,76 -> 522,84 -> 524,84 -> 524,75 -> 524,84 -> 526,84 -> 526,81 -> 526,84 -> 528,84 -> 528,74 -> 528,84 -> 530,84 -> 530,79 -> 530,84 -> 532,84 -> 532,77 -> 532,84 -> 534,84 -> 534,78 -> 534,84 -> 536,84 -> 536,80 -> 536,84
+522,47 -> 522,43 -> 522,47 -> 524,47 -> 524,41 -> 524,47 -> 526,47 -> 526,39 -> 526,47 -> 528,47 -> 528,39 -> 528,47
+498,30 -> 503,30
+492,34 -> 497,34
+529,112 -> 529,116 -> 526,116 -> 526,122 -> 541,122 -> 541,116 -> 535,116 -> 535,112

src/day12.ml

@@ -15,10 +15,10 @@ let parse_grid start_anywhere =
   let unvisited = ref [] in
   let grid =
     Utils.lines_of_input 12
-    |> Vec2.parse_grid (fun char -> { char; visited = false; distance = infinity })
+    |> Grid.of_lines (fun char -> { char; visited = false; distance = infinity })
   in
-  Vec2.iter_grid grid (fun pos ->
+  Grid.iter grid (fun pos ->
-    let n = Vec2.at_e grid pos in
+    let n = Grid.at_e grid pos in
     match n.char with
     | 'E' -> e := pos
     | 'S' ->
@@ -42,11 +42,11 @@ let reachable f t =
 ;;
 
 let rec path grid goal current unvisited =
-  let current_node = Vec2.at_e grid current in
+  let current_node = Grid.at_e grid current in
   Vec2.directions
   |> List.map (fun dir -> Vec2.(current + dir))
   |> List.iter (fun neighbor ->
-    match Vec2.at grid neighbor with
+    match Grid.at grid neighbor with
     | Some node when (not node.visited) && reachable current_node.char node.char ->
       let new_distance = current_node.distance + 1 in
       if new_distance < node.distance then node.distance <- new_distance;
@@ -57,12 +57,12 @@ let rec path grid goal current unvisited =
   unvisited
     := List.sort
          (fun a b ->
-           let a = Vec2.at_e grid a in
+           let a = Grid.at_e grid a in
-           let b = Vec2.at_e grid b in
+           let b = Grid.at_e grid b in
            a.distance - b.distance)
          !unvisited;
   match !unvisited with
-  | shortest :: _ when Vec2.(shortest = goal) -> Vec2.at grid shortest
+  | shortest :: _ when Vec2.(shortest = goal) -> Grid.at grid shortest
   | shortest :: rest -> path grid goal shortest @@ ref rest
   | [] -> None
 ;;

src/day13.ml

@@ -7,13 +7,8 @@ module Packet = struct
   [@@deriving show { with_path = false }]
 
   let of_str line =
-    let open Angstrom in
+    let open Utils.Parse in
-    let int =
+    let int = int >>= fun i -> return @@ I i in
-      take_while1 (function
-        | '0' .. '9' -> true
-        | _ -> false)
-      >>= fun s -> return @@ I (int_of_string s) <?> "int"
-    in
     let packet =
       fix (fun packet ->
         let lb, delimited, rb = char '[', sep_by (char ','), char ']' in

src/day14.ml

@@ -0,0 +1,48 @@
+open Containers
+
+type tile =
+  | Empty
+  | Rock
+  | Sand
+[@@deriving show]
+
+let parse_line line =
+  let open Utils.Parse in
+  let vec = Vec2.of_tuple <$> both int (char ',' *> int) in
+  let vec_list = sep_by (string " -> ") vec in
+  Result.get_or_failwith @@ parse_string ~consume:All vec_list line
+;;
+
+let draw_rocks grid points =
+  let open Grid in
+  let _ =
+    points
+    |> List.reduce (fun a b ->
+      iter_region grid a b (fun pos -> grid.%(pos) <- Rock);
+      b)
+  in
+  ()
+;;
+
+let%expect_test "Day 14 example" =
+  let grid = Grid.init ~width:20 ~height:10 (fun _ -> Empty) in
+  [ "8,4 -> 8,6 -> 6,6"; "13,4 -> 12,4 -> 12,9 -> 4,9" ]
+  |> List.iter (fun line -> parse_line line |> draw_rocks grid);
+  Printf.printf "%s"
+  @@ Grid.draw grid (function
+    | Empty -> '.'
+    | Rock -> '#'
+    | Sand -> 'o');
+  [%expect
+    {|
+    ....................
+    ....................
+    ....................
+    ....................
+    ........#...##......
+    ........#...#.......
+    ......###...#.......
+    ............#.......
+    ............#.......
+    ....#########....... |}]
+;;

src/day8.ml

@@ -1,17 +1,17 @@
 open Containers
 
 let parse_grid () =
-  Vec2.parse_grid Fun.(Char.to_string %> int_of_string) @@ Utils.lines_of_input 8
+  Grid.of_lines Fun.(Char.to_string %> int_of_string) @@ Utils.lines_of_input 8
 ;;
 
 let part1 () =
   let grid = parse_grid () in
   let num_visible = ref 0 in
-  Vec2.iter_grid grid (fun start ->
+  Grid.iter grid (fun start ->
-    let start_height = Option.get_exn_or "unreachable" @@ Vec2.at grid start in
+    let start_height = Option.get_exn_or "unreachable" @@ Grid.at grid start in
     let rec walk_shorter_trees start step =
       let next = Vec2.(start + step) in
-      match Vec2.at grid next with
+      match Grid.at grid next with
       | Some height when height < start_height -> walk_shorter_trees next step
       | opt -> opt
     in
@@ -28,11 +28,11 @@ let part1 () =
 let part2 () =
   let grid = parse_grid () in
   let best_score = ref 0 in
-  Vec2.iter_grid grid (fun start ->
+  Grid.iter grid (fun start ->
-    let start_height = Option.get_exn_or "unreachable" @@ Vec2.at grid start in
+    let start_height = Option.get_exn_or "unreachable" @@ Grid.at grid start in
     let rec trees_in_view start in_view step =
       let next = Vec2.(start + step) in
-      match Vec2.at grid next with
+      match Grid.at grid next with
       | Some height when height < start_height -> trees_in_view next (in_view + 1) step
       | Some _ -> in_view + 1
       | None -> in_view

src/grid.ml

@@ -0,0 +1,90 @@
+open Containers
+
+type 'a t =
+  { width : int
+  ; height : int
+  ; items : 'a array
+  }
+[@@deriving show]
+
+let vec2_of_idx ~width ~idx =
+  let y = idx / width in
+  let x = idx mod width in
+  Vec2.of_tuple (x, y)
+;;
+
+let idx_of_vec2 width vec = Vec2.(Int.((width * vec.y) + vec.x))
+
+let in_bounds grid point =
+  let x, y = Vec2.to_tuple point in
+  x >= 0 && x < grid.width && y >= 0 && y < grid.height
+;;
+
+let at grid point =
+  if in_bounds grid point
+  then Array.get_safe grid.items @@ idx_of_vec2 grid.width point
+  else None
+;;
+
+let at_e (grid : 'a t) (point : Vec2.t) =
+  Option.get_exn_or "point out of bounds!" @@ at grid point
+;;
+
+let set_e grid point item = Array.set grid.items (idx_of_vec2 grid.width point) item
+let ( .%() ) = at_e
+let ( .%()<- ) = set_e
+
+let find (grid : 'a t) pred =
+  let open Option.Infix in
+  let* idx, item = Array.find_idx pred grid.items in
+  Some (vec2_of_idx ~width:grid.width ~idx, item)
+;;
+
+let init ~width ~height init =
+  { width
+  ; height
+  ; items = Array.init (width * height) (fun idx -> init @@ vec2_of_idx ~width ~idx)
+  }
+;;
+
+let of_lines parse_char lines : 'a t =
+  match lines with
+  | first_line :: _ ->
+    let width = String.length first_line in
+    let height = List.length lines in
+    let yeet =
+      lines
+      |> List.map String.to_list
+      |> List.flatten
+      |> List.map parse_char
+      |> Array.of_list
+    in
+    { width; height; items = yeet }
+  | _ -> failwith "somethin fucd up"
+;;
+
+let iter_region grid a b callback =
+  let open Vec2 in
+  for y = min a.y b.y to max a.y b.y do
+    for x = min a.x b.x to max a.x b.x do
+      let pos = { x; y } in
+      if in_bounds grid pos then callback pos
+    done
+  done
+;;
+
+let iter grid callback =
+  let a = Vec2.of_tuple (0, 0) in
+  let b = Vec2.of_tuple (grid.width - 1, grid.height - 1) in
+  iter_region grid a b callback
+;;
+
+let draw grid printer =
+  let str = ref [] in
+  iter grid (fun point ->
+    let item = grid.%(point) in
+    let char = printer item in
+    str := !str @ [ char ];
+    if point.x = grid.width - 1 then str := !str @ [ '\n' ]);
+  String.of_list !str
+;;

src/grid.mli

@@ -0,0 +1,13 @@
+type 'a t [@@deriving show]
+
+val at : 'a t -> Vec2.t -> 'a option
+val at_e : 'a t -> Vec2.t -> 'a
+val set_e : 'a t -> Vec2.t -> 'a -> unit
+val ( .%() ) : 'a t -> Vec2.t -> 'a
+val ( .%()<- ) : 'a t -> Vec2.t -> 'a -> unit
+val init : width:int -> height:int -> (Vec2.t -> 'a) -> 'a t
+val of_lines : (char -> 'a) -> string list -> 'a t
+val find : 'a t -> ('a -> bool) -> (Vec2.t * 'a) option
+val iter_region : 'a t -> Vec2.t -> Vec2.t -> (Vec2.t -> unit) -> unit
+val iter : 'a t -> (Vec2.t -> unit) -> unit
+val draw : 'a t -> ('a -> char) -> string

src/utils.ml

@@ -9,3 +9,15 @@ let lines_of_input day =
   let path = Printf.sprintf "%s/day%d.tt" base_path day in
   IO.(with_in path read_lines_l)
 ;;
+
+module Parse = struct
+  include Angstrom
+
+  let int =
+    take_while1 (function
+      | '0' .. '9' -> true
+      | _ -> false)
+    >>| int_of_string
+    <?> "int"
+  ;;
+end

src/vec2.ml

@@ -1,65 +1,19 @@
 open Containers
 
-type t = int * int [@@deriving show]
+type t =
-
+  { x : int
-type 'a grid =
+  ; y : int
-  { width : int
-  ; height : int
-  ; items : 'a array
   }
 [@@deriving show]
 
-let origin = 0, 0
+let origin = { x = 0; y = 0 }
-let up = 0, 1
+let up = { x = 0; y = 1 }
-let down = 0, -1
+let down = { x = 0; y = -1 }
-let left = -1, 0
+let left = { x = -1; y = 0 }
-let right = 1, 0
+let right = { x = 1; y = 0 }
 let directions = [ up; down; left; right ]
-let of_tuple x = x
+let of_tuple (x, y) = { x; y }
-let to_tuple x = x
+let to_tuple { x; y } = x, y
-let ( + ) a b = Pair.map_same2 ( + ) a b
+let ( + ) a b = { x = a.x + b.x; y = a.y + b.y }
-let ( - ) a b = Pair.map_same2 ( - ) a b
+let ( - ) a b = { x = a.x - b.x; y = a.y - b.y }
-let ( = ) a b = Pair.equal ( = ) ( = ) a b
+let ( = ) a b = a.x = b.x && a.y = b.y
-
-let at (grid : 'a grid) (point : t) =
-  let x, y = point in
-  if x >= 0 && x < grid.width && y >= 0 && y < grid.height
-  then Array.get_safe grid.items @@ Int.((grid.width * y) + x)
-  else None
-;;
-
-let at_e (grid : 'a grid) (point : t) =
-  Option.get_exn_or "out of bounds!" @@ at grid point
-;;
-
-let find (grid : 'a grid) pred =
-  let open Option.Infix in
-  let* idx, item = Array.find_idx pred grid.items in
-  let y = idx / grid.width in
-  let x = idx mod grid.width in
-  Some ((x, y), item)
-;;
-
-let parse_grid parse_char lines : 'a grid =
-  match lines with
-  | first_line :: _ ->
-    let width = String.length first_line in
-    let height = List.length lines in
-    let yeet =
-      lines
-      |> List.map String.to_list
-      |> List.flatten
-      |> List.map parse_char
-      |> Array.of_list
-    in
-    { width; height; items = yeet }
-  | _ -> failwith "somethin fucd up"
-;;
-
-let iter_grid (grid : 'a grid) callback =
-  for y = 0 to Int.(grid.height - 1) do
-    for x = 0 to Int.(grid.width - 1) do
-      callback (x, y)
-    done
-  done
-;;

src/vec2.mli

@@ -1,5 +1,8 @@
-type t [@@deriving show]
+type t =
-type 'a grid [@@deriving show]
+  { x : int
+  ; y : int
+  }
+[@@deriving show]
 
 val origin : t
 val up : t
@@ -12,8 +15,3 @@ val to_tuple : t -> int * int
 val ( + ) : t -> t -> t
 val ( - ) : t -> t -> t
 val ( = ) : t -> t -> bool
-val at : 'a grid -> t -> 'a option
-val at_e : 'a grid -> t -> 'a
-val parse_grid : (char -> 'a) -> string list -> 'a grid
-val find : 'a grid -> ('a -> bool) -> (t * 'a) option
-val iter_grid : 'a grid -> (t -> unit) -> unit