From: Scott Worley Date: Tue, 29 Nov 2011 15:31:20 +0000 (-0800) Subject: Don't use 0 for uninitialized indexes X-Git-Url: http://git.scottworley.com/planeteer/commitdiff_plain/fb8eccbfa74c0ac19f24d40cbc3b7e660eda9eeb?hp=311b26d48114468d26758f2a30b1d794cb324102 Don't use 0 for uninitialized indexes 0 is a valid index. It can legitimately be the head of the optimal path. When it was the head of the optimal path, DescribePath() would print nothing. This fixes that bug. --- diff --git a/planeteer.go b/planeteer.go index 67a843d..e3c04cf 100644 --- a/planeteer.go +++ b/planeteer.go @@ -241,9 +241,11 @@ type State struct { } const ( - CELL_UNINITIALIZED = -2147483647 + iota - CELL_BEING_EVALUATED - CELL_RUBISH + FROM_ROOT = -2147483647 + iota + FROM_UNINITIALIZED + VALUE_UNINITIALIZED + VALUE_BEING_EVALUATED + VALUE_RUBISH ) func EncodeIndex(dims, addr []int) int32 { @@ -273,7 +275,8 @@ func DecodeIndex(dims []int, index int32) []int { func CreateStateTable(data planet_data, dims []int) []State { table := make([]State, StateTableSize(dims)) for i := range table { - table[i].value = CELL_UNINITIALIZED + table[i].value = VALUE_UNINITIALIZED + table[i].from = FROM_UNINITIALIZED } addr := make([]int, NumDimensions) @@ -281,7 +284,9 @@ func CreateStateTable(data planet_data, dims []int) []State { addr[Edens] = *start_edens addr[Location] = data.p2i[*start] addr[Traded] = 1 - table[EncodeIndex(dims, addr)].value = int32(*funds) + start_index := EncodeIndex(dims, addr) + table[start_index].value = int32(*funds) + table[start_index].from = FROM_ROOT return table } @@ -306,15 +311,15 @@ var cell_filled_count int func CellValue(data planet_data, dims []int, table []State, addr []int) int32 { my_index := EncodeIndex(dims, addr) - if table[my_index].value == CELL_BEING_EVALUATED { + if table[my_index].value == VALUE_BEING_EVALUATED { panic("Circular dependency") } - if table[my_index].value != CELL_UNINITIALIZED { + if table[my_index].value != VALUE_UNINITIALIZED { return table[my_index].value } - table[my_index].value = CELL_BEING_EVALUATED + table[my_index].value = VALUE_BEING_EVALUATED - best_value := int32(CELL_RUBISH) + best_value := int32(VALUE_RUBISH) best_source := make([]int, NumDimensions) other := make([]int, NumDimensions) copy(other, addr) @@ -505,7 +510,7 @@ func CellValue(data planet_data, dims []int, table []State, addr []int) int32 { // Sanity check: This cell was in state BEING_EVALUATED // the whole time that it was being evaluated. - if table[my_index].value != CELL_BEING_EVALUATED { + if table[my_index].value != VALUE_BEING_EVALUATED { panic(my_index) } @@ -566,7 +571,10 @@ func Commas(n int32) (s string) { } func DescribePath(data planet_data, dims []int, table []State, start int32) (description []string) { - for index := start; index > 0 && table[index].from > 0; index = table[index].from { + for index := start; table[index].from > FROM_ROOT; index = table[index].from { + if table[index].from == FROM_UNINITIALIZED { + panic(index) + } var line string addr := DecodeIndex(dims, index) prev := DecodeIndex(dims, table[index].from)