mal/logo/printer.lg

load "../logo/types.lg

to pr_str :exp :readable
if emptyp :exp [output []]
output case obj_type :exp [
  [[nil]      "nil]
  [[true]     "true]
  [[false]    "false]
  [[number]   obj_val :exp]
  [[symbol]   obj_val :exp]
  [[keyword]  word ": obj_val :exp]
  [[string]   print_string :exp :readable]
  [[list]     pr_seq obj_val :exp :readable "\( "\) :space_char]
  [[vector]   pr_seq obj_val :exp :readable "\[ "\] :space_char]
  [[hashmap]  pr_seq obj_val :exp :readable "\{ "\} :space_char]
  [[atom]     (word "\(atom :space_char pr_str obj_val :exp :readable "\) ) ]
  [[nativefn] (word "#<NativeFunction: obj_val :exp ">) ]
  [[fn]       (word "#<Function:args= pr_str fn_args :exp :readable ", :space_char "macro= fn_is_macro :exp ">) ]
  [else       (throw "error (sentence [unknown type] obj_type :exp))]
]
end

to escape_string :s
localmake "i 1
localmake "res "
while [:i <= count :s] [
  localmake "c item :i :s
  make "res word :res cond [
    [[ :c = "\\ ]     "\\\\ ]
    [[ :c = char 10 ] "\\n  ]
    [[ :c = "\" ]     "\\\" ]
    [else             :c    ]
  ]
  make "i (:i + 1)
]
output :res
end

to print_string :exp :readable
ifelse :readable [
  output (word "\" escape_string obj_val :exp "\" )
] [
  output obj_val :exp
]
end

to pr_seq :seq :readable :start_char :end_char :delim_char
localmake "res :start_char
foreach :seq [
  if # > 1 [make "res word :res :delim_char]
  make "res word :res pr_str ? :readable
]
output word :res :end_char
end