Move bemol.cc's Fragment to core library.

1 files changed, 2 insertions, 106 deletions

diff --git a/src/boot/bemol.cc b/src/boot/bemol.cc
index 64262e91..ab50f459 100644
--- a/src/boot/bemol.cc
+++ b/src/boot/bemol.cc
@@ -1,5 +1,5 @@
 // -*- C++ -*-
-// Copyright (C) 2014, Gabriel Dos Reis.
+// Copyright (C) 2014-2015, Gabriel Dos Reis.
 // All rights reserved.
 // Written by Gabriel Dos Reis.
 //
@@ -43,115 +43,11 @@
 #include <stack>
 #include <iterator>
 #include <ctype.h>
+#include <open-axiom/SourceInput>
 
 using namespace OpenAxiom;
 
 // 
-// -- Reading input source files --
-// 
-
-// A source input transform a character stream into a program fragment
-// stream, delivering a fragment one at a time.
-struct SourceInput {
-   SourceInput(std::istream& is) : input(is) { }
-   // Return the next program fragment from this input source.
-   Fragment get();
-
-private:
-   std::istream& input;
-   Line line;
-};
-
-// Return the indentation level of a line.
-// FIXME: reject or expand tabs as appropriate.
-static ColumnIndex
-indentation(const Line& line) {
-   ColumnIndex idx { };
-   for (auto c : line) {
-      if (not isspace(c))
-         break;
-      ++idx;
-   }
-   return idx;
-}
-
-// Remove trailing white-space characters from the line.
-static Line&
-trim_right(Line& line) {
-   auto n = line.length();
-   while (n > 0 and isspace(line[n-1]))
-      --n;
-   line.resize(n);
-   return line;
-}
-
-// Clean up and dress up the line with indentation information.
-static Line&
-prop_up(Line& line) {
-   line.indent = indentation(trim_right(line));
-   return line;
-}
-
-// Return true if line is entirely a negative comment.
-static bool
-negative_comment(const Line& line) {
-   if (line.indent + 1 >= line.length())
-      return false;
-   return line[line.indent] == '-' and line[line.indent + 1] == '-';
-}
-
-// Return true if line is either empty or a negative comment.
-static bool
-blank(const Line& line) {
-   return line.empty() or negative_comment(line);
-}
-
-// Return true if line is entirely a positive comment, i.e. a description.
-static bool
-positive_comment(const Line& line) {
-   if (line.indent + 1 >= line.length())
-      return false;
-   return line[line.indent] == '+' and line[line.indent + 1] == '+';
-}
-
-// Decompose the input souce file into fragments, and return one
-// fragment at a time.
-Fragment
-SourceInput::get() {
-   Fragment fragment;
-   std::stack<ColumnIndex> indents;
-
-   if (not line.empty()) {
-      indents.push(line.indent);
-      fragment.push_back(line);
-   }
-
-   while (std::getline(input, line)) {
-      ++line.number;
-      if (blank(prop_up(line)))
-         continue;              // Don't bother with ignorable comments.
-      else if (fragment.line_continuation())
-         ;
-      else if (indents.empty()) {
-         if (fragment.empty() and line.indent != 0)
-            std::cout << "warning: white space at begining of fragment"
-                      << " on line " << line.number << '\n';
-         indents.push(line.indent);
-      }
-      else if (line.indent == 0 and not positive_comment(fragment.back()))
-         break;                 // A completely new line; save for later.
-      else if (line.indent > indents.top())
-         indents.push(line.indent);
-      else {
-         while (line.indent < indents.top())
-            indents.pop();
-      }
-      fragment.push_back(line);
-   }
-   return fragment;
-}
-
-// 
 // -- Decomposing source files into lexical units of information --
 //