sudo gem install "masamune-ast"
Or add the following to your Gemfile and run bundle install
gem "masamune-ast"
Then require the gem in a file like this:
require "masamune"
Isolate and replace variables, methods, or strings in your Ruby source code according to the specific tokens allotted when the code is intially parsed:
code = <<~CODE
:hello
hello = "hello"
def hello
puts hello
end
CODE
msmn = Masamune::AbstractSyntaxTree.new(code)
msmn.replace(type: :variable, old_token_value: "hello", new_token_value: "greeting")
# This will produce the following code in string form.
:hello
greeting = "hello"
def hello
puts greeting
end
Pinpoint variables and methods in your source code even when other tokens have the same or similar spelling:
code = <<CODE
java = "java"
javascript = java + "script"
puts java + " is not " + javascript
# java
CODE
msmn = Masamune::AbstractSyntaxTree.new(code)
# Returns an array of Prism nodes
msmn.variables
msmn.variables.first.token_value
#=> "java"
msmn.variables.first.token_location
#=> (1,0)-(1,4)
# Returns an array of Prism nodes
msmn.strings
last_java_node = msmn.variables(token_value: "java").last
last_java_node.token_location
#=> (3,5)-(3,9)
code = <<CODE
ary = [1, 2, 3]
ary.sum.times do |n|
puts n
end
def foo
end
foo
foo # Call again
CODE
msmn = Masamune::AbstractSyntaxTree.new(code)
msmn.method_definitions.size
#=> 1
msmn.method_calls.size
#=> 5
msmn.all_methods.size
#=> 6
In some cases, it can be easier to look at the given lex nodes to analyze your source code:
msmn.lex_nodes
=> [#<Masamune::LexNode:0x00007fd61810cac0 @ast_id=1200, @index=0, @location=[1, 0], @state=CMDARG, @token="java", @type=:ident>,
#<Masamune::LexNode:0x00007fd61810c930 @ast_id=1200, @index=1, @location=[1, 4], @state=CMDARG, @token=" ", @type=:sp>,
#<Masamune::LexNode:0x00007fd61810c7c8 @ast_id=1200, @index=2, @location=[1, 5], @state=BEG, @token="=", @type=:op>,
…
]
lex_node = msmn.lex_nodes.first
lex_node.variable?
#=> true
lex_node.string?
#=> false
lex_node.method_definition?
#=> false
Bug reports and pull requests are welcome on GitHub at https://github.com/gazayas/masamune-ast.
The gem is available as open source under the terms of the MIT License.