Switch from get_children_blocks to get_children_indices

src/building_blocks.jl

@@ -45,7 +45,17 @@ abstract type ContainerBlock <: BuildingBlock end
 
 Return all the [`BuildingBlock`](@ref) objects includes in this container with their indices.
 """
-function get_children_blocks end
+get_children_blocks(bb::BuildingBlock) = [(i, bb[i]) for i in get_children_indices]
+
+"""
+    get_children_indices(container)
+
+Return the indices of all the children in a [`ContainerBlock`](@ref).
+
+This needs to be defined for every [`ContainerBlock`](@ref).
+It is not part of the external API, but is used by [`get_children_blocks`](@ref)
+"""
+function get_children_indices end
 
 
 """

src/containers/fixed_blocks.jl

 
 module FixedBlocks
 
-import ...BuildingBlocks: BuildingBlock, ContainerBlock
+import ...BuildingBlocks: BuildingBlock, ContainerBlock, get_children_indices
 import ...Gradients: FixedGradient
 import ...Pulses: FixedPulse
 import ...Variables: duration, variables
@@ -58,13 +58,13 @@ start_time(fb::FixedBlock, index::Symbol) = start_time(fb, Val(index))
 start_time(fb::FixedBlock, ::Val{:pulse}) = fb.pulse_delay
 start_time(fb::FixedBlock, ::Val{:gradient}) = fb.gradient_delay
 
-function get_children_blocks(fb::FixedBlock)
-    res = Tuple{Symbol, BuildingBlock}[]
+function get_children_indices(fb::FixedBlock)
+    res = Symbol[]
     if !isnothing(fb.pulse)
-        push!((:pulse, fb.pulse))
+        push!(:pulse)
     end
     if !isnothing(fb. gradient)
-        push!((:gradient, fb.gradient))
+        push!(:gradient)
     end
     return res
 end

src/containers/sequences.jl

@@ -5,7 +5,7 @@ module Sequences
 import JuMP: Model, @constraint
 import ...BuildSequences: @global_model_constructor
 import ...Variables: variables, start_time, duration, VariableType, get_free_variable, TR, end_time
-import ...BuildingBlocks: BuildingBlock, ContainerBlock, to_block, get_children_blocks, scanner_constraints!, fixed, BuildingBlockPrinter
+import ...BuildingBlocks: BuildingBlock, ContainerBlock, to_block, get_children_indices, scanner_constraints!, fixed, BuildingBlockPrinter
 import ..FixedBlocks: FixedBlock
 
 abstract type AbstractSequence <: ContainerBlock end
@@ -48,7 +48,7 @@ Sequence(model::Model, blocks...; TR=nothing, scanner=nothing) = Sequence(model,
 
 Base.length(seq::AbstractSequence) = length(seq._blocks)
 Base.getindex(seq::AbstractSequence, index) = seq._blocks[index]
-get_children_blocks(seq::AbstractSequence) = enumerate(seq._blocks)
+get_children_indices(seq::AbstractSequence) = eachindex(seq._blocks)
 
 """
     start_time(sequence::Sequence, index::Integer, args...)

src/gradients/pulsed_gradients.jl

@@ -6,7 +6,7 @@ module PulsedGradients
 import JuMP: @constraint, @variable, Model, VariableRef, owner_model, value
 import StaticArrays: SVector
 import ...Variables: qval, bval, rise_time, flat_time, slew_rate, gradient_strength, variables, duration, δ, get_free_variable, VariableType
-import ...BuildingBlocks: ContainerBlock, duration, set_simple_constraints!, fixed, start_time, get_children_blocks
+import ...BuildingBlocks: ContainerBlock, duration, set_simple_constraints!, fixed, start_time, get_children_indices
 import ...BuildSequences: @global_model_constructor
 import ..FixedGradients: FixedGradient
 import ..ChangingGradientBlocks: ChangingGradientBlock

src/gradients/slice_selects.jl

 module SliceSelects
 import JuMP: Model
-import ...BuildingBlocks: RFPulseBlock, ContainerBlock, get_children_blocks
+import ...BuildingBlocks: RFPulseBlock, ContainerBlock, get_children_indices
 import ...Variables: VariableType, slice_thickness, get_free_variable, effective_time, start_time, qvec, bmat, qval, bval
 import ...Variables: flip_angle, amplitude, phase, frequency, bandwidth, inverse_bandwidth, N_left, N_right
 import ..ConstantGradientBlocks: ConstantGradientBlock
@@ -47,7 +47,7 @@ function AbstractSliceSelect{VariableType}(model::Model, gradient_strength::SVec
 end
 
 
-get_children_blocks(select::SliceSelect) = [(symb, getproperty(select, symb)) for symb in (:flat_before, :pulse, :flat_after)]
+get_children_indices(::SliceSelect) = (:flat_before, :pulse, :flat_after)
 Base.get_index(select::SliceSelect, index::Symbol) = getproperty(select, index)
 
 start_time(select::SliceSelect, symbol::Symbol) = start_time(select, Val(symbol))