# Inserting and deleting in arrays. # # The primitives here just do the work of making space and compacting. fn slide-up _a: (addr array int), start: int, end: int, target: int { var a/esi: (addr array int) <- copy _a var src-idx/ecx: int <- copy start var dest-idx/edx: int <- copy target # if start == target, nothing to do { compare src-idx, dest-idx break-if-!= return } # if start < target, abort { compare src-idx, dest-idx break-if-> abort "slide-up: target > start; use slide-down instead" } # perform the copy { compare src-idx, end break-if->= var dest/ebx: (addr int) <- index a, dest-idx var src/eax: (addr int) <- index a, src-idx var val/eax: int <- copy *src copy-to *dest, val src-idx <- increment dest-idx <- increment loop } } fn slide-down _a: (addr array int), start: int, end: int, target: int { var a/esi: (addr array int) <- copy _a var src-idx/ecx: int <- copy end src-idx <- decrement var dest-idx/edx: int <- copy target dest-idx <- add end dest-idx <- subtract start dest-idx <- decrement # if start == target, nothing to do { compare src-idx, dest-idx break-if-!= return } # if start > target, abort { compare src-idx, dest-idx break-if-< abort "slide-down: target < start; use slide-down instead" } # perform the copy { compare src-idx, start break-if-< var dest/ebx: (addr int) <- index a, dest-idx var src/eax: (addr int) <- index a, src-idx var val/eax: int <- copy *src copy-to *dest, val src-idx <- decrement dest-idx <- decrement loop } } fn test-slide-up { check-slide-up "0 1 2 3 0", 1/start 1/end, 0/target, "0 1 2 3 0", "F - test-slide-up/empty-interval" check-slide-up "0 1 2 3 0", 1/start 2/end, 0/target, "1 1 2 3 0", "F - test-slide-up/single-non-overlapping" check-slide-up "0 0 0 1 2 3 0", 3/start 6/end, 0/target, "1 2 3 1 2 3 0", "F - test-slide-up/multiple-non-overlapping" check-slide-up "0 1 2 3 0", 1/start 4/end, 0/target, "1 2 3 3 0", "F - test-slide-up/overlapping" } fn test-slide-down { check-slide-down "0 1 2 3 0", 1/start 1/end, 4/target, "0 1 2 3 0", "F - test-slide-down/empty-interval" check-slide-down "0 1 2 3 0", 1/start 2/end, 4/target, "0 1 2 3 1", "F - test-slide-down/single-non-overlapping" check-slide-down "0 1 2 3 0 0 0", 1/start 4/end, 4/target, "0 1 2 3 1 2 3", "F - test-slide-down/multiple-non-overlapping" check-slide-down "0 1 2 3 0", 1/start 4/end, 2/target, "0 1 1 2 3", "F - test-slide-down/overlapping" } # helpers for tests fn check-slide-up before: (addr array byte), start: int, end: int, target: int, after: (addr array byte), msg: (addr array byte) { var arr-h: (handle array int) var arr-ah/eax: (addr handle array int) <- address arr-h parse-array-of-decimal-ints before, arr-ah var arr/eax: (addr array int) <- lookup *arr-ah slide-up arr, start, end, target check-array-equal arr, after, msg } fn check-slide-down before: (addr array byte), start: int, end: int, target: int, after: (addr array byte), msg: (addr array byte) { var arr-h: (handle array int) var arr-ah/eax: (addr handle array int) <- address arr-h parse-array-of-decimal-ints before, arr-ah var arr/eax: (addr array int) <- lookup *arr-ah slide-down arr, start, end, target check-array-equal arr, after, msg }