lib/raabro.rb in raabro-1.1.3 vs lib/raabro.rb in raabro-1.1.4

@@ -1,7 +1,7 @@
 #--
-# Copyright (c) 2015-2016, John Mettraux, [e-mail]
+# Copyright (c) 2015-2017, John Mettraux, [e-mail]
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
 # in the Software without restriction, including without limitation the rights
 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
@@ -23,11 +23,11 @@
 #++
 
 
 module Raabro
 
-  VERSION = '1.1.3'
+  VERSION = '1.1.4'
 
   class Input
 
     attr_accessor :string, :offset
     attr_reader :options
@@ -53,10 +53,15 @@
 
     def tring(l=-1)
 
       l < 0 ? @string[@offset..l] : @string[@offset, l]
     end
+
+    def at(i)
+
+      @string[i, 1]
+    end
   end
 
   class Tree
 
     attr_accessor :name, :input
@@ -179,10 +184,78 @@
 
     def even_children
 
       cs = []; @children.each_with_index { |c, i| cs << c if i.even? }; cs
     end
+
+    def extract_error
+
+#Raabro.pp(self, colors: true)
+      err_tree, stack = lookup_error || lookup_all_error
+
+      line, column = line_and_column(err_tree.offset)
+
+      err_message =
+        if stack
+          path = stack
+           .compact.reverse.take(3).reverse
+           .collect(&:inspect).join('/')
+          "parsing failed .../#{path}"
+        else
+          "parsing failed, not all input was consumed"
+        end
+      visual =
+        visual(line, column)
+
+      [ line, column, err_tree.offset, err_message, visual ]
+    end
+
+    def lookup_error(stack=[])
+
+#print "le(): "; Raabro.pp(self, colors: true)
+      return nil if @result != 0
+      return [ self, stack ] if @children.empty?
+      @children.each { |c|
+        es = c.lookup_error(stack.dup.push(self.name))
+        return es if es }
+      nil
+    end
+
+    # Not "lookup all errors" but "lookup all error", in other
+    # words lookup the point up until which the parser stopped (not
+    # consuming all the input)
+    #
+    def lookup_all_error
+
+#print "lae(): "; Raabro.pp(self, colors: true)
+      @children.each { |c| return [ c, nil ] if c.result == 0 }
+      @children.reverse.each { |c| es = c.lookup_all_error; return es if es }
+      nil
+    end
+
+    def line_and_column(offset)
+
+      line = 1
+      column = 0
+
+      (0..offset).each do |off|
+
+        column += 1
+        next unless @input.at(off) == "\n"
+
+        line += 1
+        column = 0
+      end
+
+      [ line, column ]
+    end
+
+    def visual(line, column)
+
+      @input.string.split("\n")[line - 1] + "\n" +
+      ' ' * (column - 1) + '^---'
+    end
   end
 
   module ModuleMethods
 
     def _match(name, input, parter, regex_or_string)
@@ -470,19 +543,31 @@
           _parse(root, Raabro::Input.new(input, opts))
         else
           all(nil, Raabro::Input.new(input, opts), root)
         end
 
+      return reparse_for_error(input, opts, t) if opts[:error] && t.result != 1
       return nil if opts[:prune] != false && t.result != 1
 
       t = t.children.first if t.parter == :all
 
       return rewrite(t) if opts[:rewrite] != false
 
       t
     end
 
+    def reparse_for_error(input, opts, t)
+
+      t =
+        opts[:prune] == false ?
+        t :
+        parse(input, opts.merge(error: false, rewrite: false, prune: false))
+#Raabro.pp(t, colours: true)
+
+      t.extract_error
+    end
+
     def rewrite_(tree)
 
       t = tree.lookup(nil)
 
       t ? rewrite(t) : nil
@@ -518,14 +603,20 @@
     # Red         0;31     Light Red     1;31
     # Purple      0;35     Light Purple  1;35
     # Brown       0;33     Yellow        1;33
     # Light Gray  0;37     White         1;37
 
-  def self.pp(tree, depth=0)
+  def self.pp(tree, depth=0, opts={})
 
+    fail ArgumentError.new(
+      'tree is not an instance of Raabro::Tree'
+    ) unless tree.is_a?(Raabro::Tree)
+
+    depth, opts = 0, depth if depth.is_a?(Hash)
+
     _rs, _dg, _gn, _yl, _bl, _lg =
-      $stdout.tty? ?
+      (opts[:colors] || opts[:colours] || $stdout.tty?) ?
       [ "", "", "", "", "", "" ] :
       [ '', '', '', '', '', '' ]
 
     lc = tree.result == 1 ? _gn : _dg
     nc = tree.result == 1 ? _bl : _lg
@@ -552,10 +643,10 @@
     print "#{lc}#{tree.result}"
     print " #{nc}#{tree.name.inspect} #{lc}#{tree.offset},#{tree.length}"
     print str
     print "#{_rs}\n"
 
-    tree.children.each { |c| self.pp(c, depth + 1) }
+    tree.children.each { |c| self.pp(c, depth + 1, opts) }
 
     if depth == 0
       print _dg
       print "input ln: #{tree.input.string.length}, tree ln: #{tree.length} "
       print "---t\n"