crystal/env.cr

   1 require "./types"
   2 require "./error"
   3
   4 module Mal
   5
   6   class Env
   7     property data
   8
   9     def initialize(@outer)
  10       @data = {} of String => Mal::Type
  11     end
  12
  13     def initialize(@outer, binds, exprs : Array(Mal::Type))
  14       @data = {} of String => Mal::Type
  15
  16       eval_error "binds must be list or vector" unless binds.is_a? Array
  17
  18       # Note:
  19       # Array#zip() can't be used because overload resolution failed
  20       (0...binds.size).each do |idx|
  21         sym, expr = binds[idx].unwrap, exprs[idx]
  22         eval_error "bind list must be symbol" unless sym.is_a? Mal::Symbol
  23         @data[sym.str] = expr
  24       end
  25     end
  26
  27     def set(key, value)
  28       @data[key] = value
  29     end
  30
  31     def find(key)
  32       return self if @data.has_key? key
  33
  34       o = @outer
  35       if o
  36         o.find key
  37       else
  38         nil
  39       end
  40     end
  41
  42     def get(key)
  43       e = find(key)
  44       eval_error "#{key} not found" unless e
  45       e.data[key]
  46     end
  47   end
  48
  49 end