Docile

Execute a block in the context of an object whose methods represent the commands in a DSL.

@note Use with an imperative DSL (commands modify the context object)

Use this method to execute an imperative DSL, which means that:

1. Each command mutates the state of the DSL context object
2. The return value of each command is ignored
3. The final return value is the original context object

@example Use a String as a DSL

Docile.dsl_eval("Hello, world!") do
  reverse!
  upcase!
end
#=> "!DLROW ,OLLEH"

@example Use an Array as a DSL

Docile.dsl_eval([]) do
  push 1
  push 2
  pop
  push 3
end
#=> [1, 3]

@param dsl [Object] context object whose methods make up the DSL @param args [Array] arguments to be passed to the block @param block [Proc] the block of DSL commands to be executed against the

`dsl` context object

@return [Object] the `dsl` context object after executing the block

# File lib/docile.rb, line 42
def dsl_eval(dsl, *args, &block)
  exec_in_proxy_context(dsl, FallbackContextProxy, *args, &block)
  dsl
end

Execute a block in the context of an immutable object whose methods, and the methods of their return values, represent the commands in a DSL.

@note Use with a functional DSL (commands return successor

context objects)

Use this method to execute a functional DSL, which means that:

1. The original DSL context object is never mutated
2. Each command returns the next DSL context object
3. The final return value is the value returned by the last command

@example Use a frozen String as a DSL

Docile.dsl_eval_immutable("I'm immutable!".freeze) do
  reverse
  upcase
end
#=> "!ELBATUMMI M'I"

@example Use a Float as a DSL

Docile.dsl_eval_immutable(84.5) do
  fdiv(2)
  floor
end
#=> 42

@param dsl [Object] immutable context object whose methods make up the

initial DSL

@param args [Array] arguments to be passed to the block @param block [Proc] the block of DSL commands to be executed against the

`dsl` context object and successor return values

@return [Object] the return value of the final command in the block

# File lib/docile.rb, line 80
def dsl_eval_immutable(dsl, *args, &block)
  exec_in_proxy_context(dsl, ChainingFallbackContextProxy, *args, &block)
end