Primitive While Loop

Repeatedly executes body while cond returns TRUE, like R's while loop. The loop state is initialized with init and passed through each iteration. Otherwise, no state is maintained between iterations.

Usage

nvl_while(init, cond, body)

Arguments

init

(named list())
Named list of initial state values.

cond

(function)
Condition function that receives the current state as arguments and outputs whether to continue the loop.

body

(function)
Body function that receives the current state as arguments and returns a named list with the same structure, dtypes, and shapes as init.

Value

Named list with the same structure as init containing the final state after the loop terminates.

Implemented Rules

• stablehlo

StableHLO

Lowers to stablehlo::hlo_while().

See also

nv_while()

Examples

jit_eval({
  nvl_while(
    init = list(i = 0L, total = 0L),
    cond = function(i, total) i <= 5L,
    body = function(i, total) list(
      i = i + 1L,
      total = total + i
    )
  )
})
#> $i
#> AnvilTensor
#>  6
#> [ CPUi32?{} ] 
#> 
#> $total
#> AnvilTensor
#>  15
#> [ CPUi32?{} ] 
#>