Module: SyntaxTree::WithScope
- Defined in:
- lib/syntax_tree/with_scope.rb
Overview
WithScope is a module intended to be included in classes inheriting from Visitor. The module overrides a few visit methods to automatically keep track of local variables and arguments defined in the current scope. Example usage:
class MyVisitor < Visitor
include WithScope
def visit_ident(node)
# Check if we're visiting an identifier for an argument, a local
# variable or something else
local = current_scope.find_local(node)
if local.type == :argument
# handle identifiers for arguments
elsif local.type == :variable
# handle identifiers for variables
else
# handle other identifiers, such as method names
end
end
end
Defined Under Namespace
Classes: Scope
Instance Attribute Summary collapse
-
#current_scope ⇒ Object
readonly
Returns the value of attribute current_scope.
Instance Method Summary collapse
- #initialize(*args, **kwargs, &block) ⇒ Object
-
#visit_binary(node) ⇒ Object
Visit for capturing local variables defined in regex named capture groups.
- #visit_block_var(node) ⇒ Object (also: #visit_lambda_var)
- #visit_blockarg(node) ⇒ Object
-
#visit_class(node) ⇒ Object
Visits for nodes that create new scopes, such as classes, modules and method definitions.
- #visit_def(node) ⇒ Object
- #visit_kwrest_param(node) ⇒ Object
-
#visit_method_add_block(node) ⇒ Object
When we find a method invocation with a block, only the code that happens inside of the block needs a fresh scope.
- #visit_module(node) ⇒ Object
-
#visit_params(node) ⇒ Object
Visit for keeping track of local arguments, such as method and block arguments.
-
#visit_pinned_var_ref(node) ⇒ Object
Visit for keeping track of local variable definitions.
- #visit_rest_param(node) ⇒ Object
-
#visit_var_field(node) ⇒ Object
Visit for keeping track of local variable definitions.
-
#visit_var_ref(node) ⇒ Object
Visits for keeping track of variable and argument usages.
-
#visit_vcall(node) ⇒ Object
When using regex named capture groups, vcalls might actually be a variable.
Instance Attribute Details
#current_scope ⇒ Object (readonly)
Returns the value of attribute current_scope.
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# File 'lib/syntax_tree/with_scope.rb', line 120 def current_scope @current_scope end |
Instance Method Details
#initialize(*args, **kwargs, &block) ⇒ Object
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# File 'lib/syntax_tree/with_scope.rb', line 122 def initialize(*args, **kwargs, &block) super @current_scope = Scope.new(0) @next_scope_id = 0 end |
#visit_binary(node) ⇒ Object
Visit for capturing local variables defined in regex named capture groups
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# File 'lib/syntax_tree/with_scope.rb', line 239 def visit_binary(node) if node.operator == :=~ left = node.left if left.is_a?(RegexpLiteral) && left.parts.length == 1 && left.parts.first.is_a?(TStringContent) content = left.parts.first value = content.value location = content.location start_line = location.start_line Regexp .new(value, Regexp::FIXEDENCODING) .names .each do |name| offset = value.index(/\(\?<#{Regexp.escape(name)}>/) line = start_line + value[0...offset].count("\n") # We need to add 3 to account for these three characters # prefixing a named capture (?< column = location.start_column + offset + 3 if value[0...offset].include?("\n") column = value[0...offset].length - value[0...offset].rindex("\n") + 3 - 1 end ident_location = Location.new( start_line: line, start_char: location.start_char + offset, start_column: column, end_line: line, end_char: location.start_char + offset + name.length, end_column: column + name.length ) identifier = Ident.new(value: name, location: ident_location) current_scope.add_local_definition(identifier, :variable) end end end super end |
#visit_block_var(node) ⇒ Object Also known as: visit_lambda_var
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# File 'lib/syntax_tree/with_scope.rb', line 192 def visit_block_var(node) node.locals.each do |local| current_scope.add_local_definition(local, :variable) end super end |
#visit_blockarg(node) ⇒ Object
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# File 'lib/syntax_tree/with_scope.rb', line 185 def visit_blockarg(node) name = node.name current_scope.add_local_definition(name, :argument) if name super end |
#visit_class(node) ⇒ Object
Visits for nodes that create new scopes, such as classes, modules and method definitions.
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# File 'lib/syntax_tree/with_scope.rb', line 131 def visit_class(node) with_scope { super } end |
#visit_def(node) ⇒ Object
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# File 'lib/syntax_tree/with_scope.rb', line 147 def visit_def(node) with_scope { super } end |
#visit_kwrest_param(node) ⇒ Object
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# File 'lib/syntax_tree/with_scope.rb', line 178 def visit_kwrest_param(node) name = node.name current_scope.add_local_definition(name, :argument) if name super end |
#visit_method_add_block(node) ⇒ Object
When we find a method invocation with a block, only the code that happens inside of the block needs a fresh scope. The method invocation itself happens in the same scope.
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# File 'lib/syntax_tree/with_scope.rb', line 142 def visit_method_add_block(node) visit(node.call) with_scope(current_scope) { visit(node.block) } end |
#visit_module(node) ⇒ Object
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# File 'lib/syntax_tree/with_scope.rb', line 135 def visit_module(node) with_scope { super } end |
#visit_params(node) ⇒ Object
Visit for keeping track of local arguments, such as method and block arguments.
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# File 'lib/syntax_tree/with_scope.rb', line 153 def visit_params(node) add_argument_definitions(node.requireds) node.posts.each do |param| current_scope.add_local_definition(param, :argument) end node.keywords.each do |param| current_scope.add_local_definition(param.first, :argument) end node.optionals.each do |param| current_scope.add_local_definition(param.first, :argument) end super end |
#visit_pinned_var_ref(node) ⇒ Object
Visit for keeping track of local variable definitions
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# File 'lib/syntax_tree/with_scope.rb', line 210 def visit_pinned_var_ref(node) value = node.value current_scope.add_local_usage(value, :variable) if value.is_a?(Ident) super end |
#visit_rest_param(node) ⇒ Object
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# File 'lib/syntax_tree/with_scope.rb', line 171 def visit_rest_param(node) name = node.name current_scope.add_local_definition(name, :argument) if name super end |
#visit_var_field(node) ⇒ Object
Visit for keeping track of local variable definitions
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# File 'lib/syntax_tree/with_scope.rb', line 202 def visit_var_field(node) value = node.value current_scope.add_local_definition(value, :variable) if value.is_a?(Ident) super end |
#visit_var_ref(node) ⇒ Object
Visits for keeping track of variable and argument usages
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# File 'lib/syntax_tree/with_scope.rb', line 218 def visit_var_ref(node) value = node.value if value.is_a?(Ident) definition = current_scope.find_local(value.value) current_scope.add_local_usage(value, definition.type) if definition end super end |
#visit_vcall(node) ⇒ Object
When using regex named capture groups, vcalls might actually be a variable
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# File 'lib/syntax_tree/with_scope.rb', line 230 def visit_vcall(node) value = node.value definition = current_scope.find_local(value.value) current_scope.add_local_usage(value, definition.type) if definition super end |