src/astprinter.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Copyright 2012 Jean Privat <jean@pryen.org>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 # print AST in an human form
  18 module astprinter
  19
  20 import typing
  21 import phase
  22 intrude import parser
  23 import literal
  24
  25 private class ASTPrinterVisitor
  26         super Visitor
  27         redef fun visit(node)
  28         do
  29                 node.accept_printer(self)
  30         end
  31
  32         var out = new List[String]
  33         var indent_level = 0
  34
  35         var has_eol = true
  36
  37         fun eol
  38         do
  39                 if has_eol then return
  40                 out.add("\n")
  41                 for x in [0..indent_level[ do out.add("\t")
  42                 has_eol = true
  43         end
  44
  45         var last_current: nullable ANode
  46
  47         fun write(s: String)
  48         do
  49                 if last_current != current_node then
  50                         last_current = current_node
  51                         var l = current_node._location
  52                         if l != null then
  53                                 eol
  54                                 out.add(s)
  55                                 out.add("\t# {l.colored_line("0;32").split_with('\n').first}")
  56                                 has_eol = false
  57                                 eol
  58                                 return
  59                         end
  60                 end
  61                 out.add(s)
  62                 has_eol = false
  63         end
  64
  65         fun indent do indent_level += 1
  66         fun unindent do indent_level -= 1
  67 end
  68
  69 redef class ANode
  70         # print the tree (using the semantic information) on screen
  71         # This method is used to debug AST transformations
  72         fun print_tree
  73         do
  74                 var v = new ASTPrinterVisitor
  75                 v.enter_visit(self)
  76                 v.eol
  77                 for s in v.out do
  78                         printn s
  79                 end
  80         end
  81
  82         private fun accept_printer(v: ASTPrinterVisitor)
  83         do
  84                 v.eol
  85                 v.write("({inspect}")
  86                 v.indent
  87                 visit_all(v)
  88                 v.write(")")
  89                 v.unindent
  90         end
  91 end
  92
  93 redef class ABlockExpr
  94         redef fun accept_printer(v)
  95         do
  96                 for x in n_expr do
  97                         v.enter_visit(x)
  98                         v.eol
  99                 end
 100         end
 101 end
 102
 103 redef class AIntExpr
 104         redef fun accept_printer(v)
 105         do
 106                 v.write(value.to_s)
 107         end
 108 end
 109
 110 redef class ANewExpr
 111         redef fun accept_printer(v)
 112         do
 113                 v.write("new {mtype.as(not null)}.{mproperty.as(not null)}")
 114                 if not n_args.n_exprs.is_empty then
 115                         v.write("(")
 116                         v.indent
 117                         var is_first = true
 118                         for a in n_args.n_exprs do
 119                                 if is_first then is_first = false else v.write(",")
 120                                 v.enter_visit(a)
 121                         end
 122                         v.unindent
 123                         v.write(")")
 124                 end
 125         end
 126 end
 127
 128 redef class ASendExpr
 129         redef fun accept_printer(v)
 130         do
 131                 v.enter_visit(n_expr)
 132                 v.write(".{mproperty.name}")
 133                 if not raw_arguments.is_empty then
 134                         v.write("(")
 135                         v.indent
 136                         var is_first = true
 137                         for a in raw_arguments.as(not null) do
 138                                 if is_first then is_first = false else v.write(",")
 139                                 v.enter_visit(a)
 140                         end
 141                         v.unindent
 142                         v.write(")")
 143                 end
 144         end
 145 end
 146
 147 redef class AVarExpr
 148         redef fun accept_printer(v)
 149         do
 150                 var name = variable.name
 151                 if name == "" then name = "t{variable.object_id}"
 152                 v.write(name)
 153         end
 154 end
 155
 156 redef class AVarAssignExpr
 157         redef fun accept_printer(v)
 158         do
 159                 var name = variable.name
 160                 if name == "" then name = "t{variable.object_id}"
 161                 v.write("{name} = ")
 162                 v.indent
 163                 v.enter_visit(n_value)
 164                 v.unindent
 165         end
 166 end