Class: Kumi::Core::Analyzer::Passes::SNASTPass

Inherits:
PassBase
  • Object
show all
Defined in:
lib/kumi/core/analyzer/passes/snast_pass.rb

Overview

Semantic NAST Pass (SNAST)

  • Rewrites intrinsic control and reductions into first-class nodes.

  • Attaches semantic stamps to every node: meta = { axes:, dtype: }.

  • Uses side tables for types/scopes; no meta.

Reduction rule (default sugar):

If not explicitly annotated, a reduction over arguments reduces the LAST axis:
  a = lub_by_prefix(arg_axes_list)
  over = [a.last]; out_axes = a[0...-1]

Inputs (state):

:nast_module          => Kumi::Core::NAST::Module (topologically ordered)
:metadata_table       => Hash[node_key => { result_scope:, result_type:, arg_scopes?: ... }]
:declaration_table    => Hash[name => { result_scope:, result_type: }]
:input_table          => [{path_fqn:, axes:, dtype:}] or Hash[path_fqn] => { axes:, dtype: }

Output (state):

:snast_module         => Kumi::Core::NAST::Module (with NAST::Select / NAST::Reduce nodes)

TODO: If downstream never keys by node ids, consider removing dependence on node.id. TODO: Use Error helpers with provenance

Instance Method Summary collapse

Methods inherited from PassBase

#debug, #debug_enabled?, #initialize

Methods included from ErrorReporting

#inferred_location, #raise_localized_error, #raise_syntax_error, #raise_type_error, #report_enhanced_error, #report_error, #report_semantic_error, #report_syntax_error, #report_type_error

Constructor Details

This class inherits a constructor from Kumi::Core::Analyzer::Passes::PassBase

Instance Method Details

#axes_of(n) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 206

def axes_of(n)  = Array(n.meta[:stamp]&.dig(:axes))

#dtype_of(n) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 207

def dtype_of(n) = n.meta[:stamp]&.dig(:dtype)

#lookup_input(fqn) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 233

def lookup_input(fqn)
  if @input_table.respond_to?(:find)
    @input_table.find { |x| x[:path_fqn] == fqn } || raise("Input not found for #{fqn}")
  else
    @input_table.fetch(fqn) { raise("Input not found for #{fqn}") }
  end
end

#lub_by_prefix(list) ⇒ Object

Least upper bound by prefix. All entries must be a prefix of the longest.



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 210

def lub_by_prefix(list)
  return [] if list.empty?

  cand = list.max_by(&:length) || []
  list.each do |ax|
    raise Kumi::Core::Errors::SemanticError, "prefix mismatch: #{ax.inspect} vs #{cand.inspect}" unless prefix?(ax, cand)
  end
  cand
end

#meta_for(node) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 205

def meta_for(node) = @metadata_table.fetch(node_key(node))

#node_key(n) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 241

def node_key(n) = "#{n.class}_#{n.id}"

#prefix?(pre, full) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 220

def prefix?(pre, full)
  pre.each_with_index.all? { |tok, i| full[i] == tok }
end

#reduce_last_axis(args_axes_list) ⇒ Object

Default reduce sugar: over last axis of the LUB of argument axes. Returns { over:, out_axes: }.

Raises:



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 226

def reduce_last_axis(args_axes_list)
  a = lub_by_prefix(args_axes_list)
  raise Kumi::Core::Errors::SemanticError, "cannot reduce scalar" if a.empty?

  { over: [a.last], out_axes: a[0...-1] }
end

#run(errors) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 29

def run(errors)
  @nast_module       = get_state(:nast_module,       required: true)
  @metadata_table    = get_state(:metadata_table,    required: true)
  @declaration_table = get_state(:declaration_table, required: true)
  @input_table       = get_state(:input_table,       required: true)
  @index_table       = get_state(:index_table,       required: true)
  @registry          = get_state(:registry,          required: true)
  @errors = errors

  debug "Building SNAST from #{@nast_module.decls.size} declarations"
  snast_module = @nast_module.accept(self)
  state.with(:snast_module, snast_module.freeze)
end

#stamp!(node, axes, dtype) ⇒ Object

———- Helpers ———-



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 200

def stamp!(node, axes, dtype)
  node.meta[:stamp] = { axes: Array(axes), dtype: dtype }.freeze
  node
end

#visit_call(n) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 104

def visit_call(n)
  if @registry.function_select?(n.fn)
    c = n.args[0].accept(self)
    t = n.args[1].accept(self)
    f = n.args[2].accept(self)
    target_axes = lub_by_prefix([axes_of(t), axes_of(f)])
    target_axes = axes_of(c) if target_axes.empty?
    unless prefix?(axes_of(c), target_axes)
      raise Kumi::Core::Errors::SemanticError,
            "select mask axes #{axes_of(c).inspect} must prefix #{target_axes.inspect} at: #{n.loc}"
    end

    out = NAST::Select.new(id: n.id, cond: c, on_true: t, on_false: f, loc: n.loc, meta: n.meta.dup)
    return stamp!(out, target_axes, dtype_of(t))
  end

  if @registry.function_reduce?(n.fn)
    raise "Reducers should only have one arg" if n.args.size != 1 # TODO: -> sugar to collapse variadics?

    arg_node = n.args.first
    visited_arg = arg_node.accept(self)
    arg_meta = visited_arg[:meta]
    arg_type = arg_meta[:stamp][:dtype]

    if Kumi::Core::Types.collection?(arg_type)
      # --- Path for FOLD (Scalar or Vectorized) ---w
      # The argument is semantically a tuple. Create a Fold node.

      # We still need to visit the child node to build the SNAST tree

      fold_node = NAST::Fold.new(
        id: n.id,
        fn: @registry.resolve_function(n.fn),
        arg: visited_arg, # The arg is the tuple/reference to the tuple
        loc: n.loc,
        meta: n.meta.dup
      )

      # The output type is the reduced scalar type (e.g., :integer for max).
      # The axes are PRESERVED because a fold is an element-wise operation
      # on the container of tuples.
      result_meta = meta_for(n)
      return stamp!(fold_node, result_meta[:result_scope], result_meta[:result_type])
    else
      # --- Path for REDUCE (Vectorized Arrays) ---
      in_axes = axes_of(visited_arg)

      if in_axes.empty?
        raise Kumi::Core::Errors::SemanticError,
              "reduce function called on a non-collection scalar: #{arg_type}"
      end

      result_meta = meta_for(n)
      out_axes = Array(result_meta[:result_scope])

      raise Kumi::Core::Errors::SemanticError, "reduce: out axes must prefix arg axes" unless prefix?(out_axes, in_axes)

      over_axes = in_axes.drop(out_axes.length)
      reduce_node = NAST::Reduce.new(
        id: n.id,
        fn: @registry.resolve_function(n.fn),
        over: over_axes,
        arg: visited_arg,
        loc: n.loc,
        meta: n.meta.dup
      )
      return stamp!(reduce_node, out_axes, result_meta[:result_type])
    end
  end

  # regular elementwise
  args = n.args.map { _1.accept(self) }
  m    = meta_for(n)
  # Use the function ID from metadata (already resolved with type awareness in NASTDimensionalAnalyzerPass)
  fn_id = m[:function] || @registry.resolve_function(n.fn)
  out = n.class.new(id: n.id, fn: fn_id.to_sym, args:, opts: n.opts, loc: n.loc)
  stamp!(out, m[:result_scope], m[:result_type])
end

#visit_const(n) ⇒ Object

———- Leaves ———-



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 59

def visit_const(n)
  meta = meta_for(n)
  out = n.class.new(id: n.id, value: n.value, loc: n.loc)
  stamp!(out, [], meta[:type])
end

#visit_declaration(d) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 50

def visit_declaration(d)
  meta = @declaration_table.fetch(d.name)
  body = d.body.accept(self)
  out  = d.class.new(id: d.id, name: d.name, body:, loc: d.loc, meta: { kind: d.kind })
  stamp!(out, meta[:result_scope], meta[:result_type])
end

#visit_hash(n) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 90

def visit_hash(n)
  pairs = n.pairs.map { _1.accept(self) }
  m    = meta_for(n)
  out  = n.class.new(id: n.id, pairs:, loc: n.loc)
  stamp!(out, m[:scope], m[:type])
end

#visit_import_call(n) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 183

def visit_import_call(n)
  args = n.args.map { _1.accept(self) }
  m = meta_for(n)
  out = n.class.new(
    id: n.id,
    fn_name: n.fn_name,
    args: args,
    input_mapping_keys: n.input_mapping_keys,
    source_module: n.source_module,
    loc: n.loc,
    meta: n.meta.dup
  )
  stamp!(out, m[:result_scope], m[:result_type])
end

#visit_index_ref(n) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 71

def visit_index_ref(n)
  m = meta_for(n)
  out = n.class.new(id: n.id, name: n.name, input_fqn: n.input_fqn, loc: n.loc)
  stamp!(out, m[:scope], m[:type])
end

#visit_input_ref(n) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 65

def visit_input_ref(n)
  ent = lookup_input(n.path_fqn)
  out = n.class.new(id: n.id, path: n.path, loc: n.loc)
  stamp!(out, ent[:axes], ent[:dtype])
end

#visit_module(mod) ⇒ Object

———- Visitor entry points ———-



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 45

def visit_module(mod)
  # decls is expected to be a Hash[name => Declaration]
  mod.class.new(decls: mod.decls.transform_values { |d| d.accept(self) })
end

#visit_pair(n) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 97

def visit_pair(n)
  value = n.value.accept(self)
  m = meta_for(n)
  out = n.class.new(id: n.id, key: n.key, value:)
  stamp!(out, m[:scope], m[:type])
end

#visit_ref(n) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 77

def visit_ref(n)
  m = meta_for(n)
  out = n.class.new(id: n.id, name: n.name, loc: n.loc)
  stamp!(out, m[:result_scope], m[:result_type])
end

#visit_tuple(n) ⇒ Object 



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# File 'lib/kumi/core/analyzer/passes/snast_pass.rb', line 83

def visit_tuple(n)
  args = n.args.map { _1.accept(self) }
  m    = meta_for(n)
  out  = n.class.new(id: n.id, args:, loc: n.loc)
  stamp!(out, m[:result_scope], m[:result_type])
end