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authorGabriel Dos Reis <gdr@axiomatics.org>2015-12-30 00:54:19 -0800
committerGabriel Dos Reis <gdr@axiomatics.org>2015-12-30 00:54:19 -0800
commitd0740d0ba443f0f24c78d321e15b41bb6c45cecd (patch)
treeca29521af72d9397dd44d4a649e04468282c2a59 /src/boot
parenta461cc79ca47e119d522fe931a43ed66a0c503f6 (diff)
downloadopen-axiom-d0740d0ba443f0f24c78d321e15b41bb6c45cecd.tar.gz
Move bemol.cc's Fragment to core library.
Diffstat (limited to 'src/boot')
-rw-r--r--src/boot/bemol.cc108
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 --
//