Functional Table Processing

Pipeline Result

Combine mapping, filtering, and reducing in one pass.

pipeline result A processing pipeline can transform values, filter them, and reduce the kept values to one result.

Pipeline Result

bonus
pipeline_result.lua
Replay: real traced execution (multi-file project)
local bonus = 1
local total = 0

for _, value in ipairs({1, 2, 3}) do
  local mapped = value + bonus
  if mapped % 2 == 0 then
    total = total + mapped
  end
end

print("bonus=" .. bonus)
print("total=" .. total)

local bonus = 0
local total = 0

for _, value in ipairs({1, 2, 3}) do
  local mapped = value + bonus
  if mapped % 2 == 0 then
    total = total + mapped
  end
end

print("bonus=" .. bonus)
print("total=" .. total)

local bonus = 3
local total = 0

for _, value in ipairs({1, 2, 3}) do
  local mapped = value + bonus
  if mapped % 2 == 0 then
    total = total + mapped
  end
end

print("bonus=" .. bonus)
print("total=" .. total)

  1. bonus ← 1, total ← 0

    1local bonus→ 1 = 1 --@bonus=0, 32local total→ 0 = 0

  2. mapped ← 2

    pass 1 of 3
    4for _1, value1 in ipairs({1, 2, 3}) do5  local mapped→ 2 = value1 + bonus16  if mapped % 2 == 0 then
    All 3 passes — pass 1 is the card above
    pass_valuemappedtotal
    11120 → 2
    2223—
    33342 → 6

  3. total ← 2

    pass 1 of 2
    5local mapped = value + bonus6if mapped2 % 2 == 0 then7  total→ 2 = total + mapped28end

  4. total ← 6

    pass 2 of 2
    5local mapped = value + bonus6if mapped4 % 2 == 0 then7  total→ 6 = total + mapped48end

  5. print("bonus=" .. bonus)

    11print("bonus=" .. bonus1)12print("total=" .. total6)
    outputbonus=1
total=6

  1. bonus ← 0, total ← 0

    1local bonus→ 0 = 02local total→ 0 = 0

  2. mapped ← 1

    pass 1 of 3
    4for _1, value1 in ipairs({1, 2, 3}) do5  local mapped→ 1 = value1 + bonus06  if mapped % 2 == 0 then
    All 3 passes — pass 1 is the card above
    pass_valuemappedtotal
    1111—
    22220 → 2
    3333—

  3. total ← 2

    5local mapped = value + bonus6if mapped2 % 2 == 0 then7  total→ 2 = total + mapped28end

  4. print("bonus=" .. bonus)

    11print("bonus=" .. bonus0)12print("total=" .. total2)
    outputbonus=0
total=2

  1. bonus ← 3, total ← 0

    1local bonus→ 3 = 32local total→ 0 = 0

  2. mapped ← 4

    pass 1 of 3
    4for _1, value1 in ipairs({1, 2, 3}) do5  local mapped→ 4 = value1 + bonus36  if mapped % 2 == 0 then
    All 3 passes — pass 1 is the card above
    pass_valuemappedtotal
    11140 → 4
    2225—
    33364 → 10

  3. total ← 4

    pass 1 of 2
    5local mapped = value + bonus6if mapped4 % 2 == 0 then7  total→ 4 = total + mapped48end

  4. total ← 10

    pass 2 of 2
    5local mapped = value + bonus6if mapped6 % 2 == 0 then7  total→ 10 = total + mapped68end

  5. print("bonus=" .. bonus)

    11print("bonus=" .. bonus3)12print("total=" .. total10)
    outputbonus=3
total=10