if statement with an implicit/explicit stack

explicit-1-if.mcfunction

execute if score #condition boolean matches 1 run function explicit-1-then

# peek
execute store result score #condition boolean run data get entity @s HandItems[0].tag.boolean_stack[-1]

execute if score #condition boolean matches 0 run function explicit-1-else

explicit-1.mcfunction

# push
data modify entity @s HandItems[0].tag.boolean_stack append value 0b
execute store success entity @s HandItems[0].tag.boolean_stack[-1] byte 1 store success score #condition boolean if block 0 0 0 minecraft:air

function explicit-1-if

# pop
data remove entity @s HandItems[0].tag.boolean_stack[-1]

explicit.mcfunction

execute as 0-0-0-0-0 run function explicit-1

implicit-1-if.mcfunction

execute if entity @s[y_rotation=1] run function implicit-1-then

# peek
teleport @s ~ ~ ~ ~ ~

execute if entity @s[y_rotation=0] run function implicit-1-else

# pop

implicit-1.mcfunction

execute store success entity @s Rotation[0] float 1 if block 0 0 0 minecraft:air

# push
execute rotated as @s run function implicit-1-if

implicit.mcfunction

execute as 0-0-0-0-0 run function implicit-1

init.mcfunction

scoreboard objectives add boolean dummy
summon minecraft:armor_stand ~ ~ ~ {UUIDMost: 0L, UUIDLeast: 0L, Marker: true, HandItems: [{id: "minecraft:tnt", Count: 1b, tag: {boolean_stack: []}}]}