LineTemplate.cpp

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//
// Class LineTemplate
//
//   An ``archetype'' for a OPAL beam line with arguments.
//   The model is stored in form of a MacroStream.  A call to the macro line
//   is expanded by first replacing the arguments, and then parsing the
//   resulting stream as a LINE definition.
//
// Copyright (c) 2008 - 2020, Paul Scherrer Institut, Villigen PSI, Switzerland
//
// All rights reserved
//
// This file is part of OPAL.
//
// OPAL is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// You should have received a copy of the GNU General Public License
// along with OPAL. If not, see <https://www.gnu.org/licenses/>.
//
 
#include "Lines/LineTemplate.h"
 
#include "Utility/PAssert.h"
 
#include <vector>
#include "AbstractObjects/OpalData.h"
#include "Lines/Line.h"
#include "OpalParser/SimpleStatement.h"
#include "Utilities/ParseError.h"
 
LineTemplate::LineTemplate()
    : Macro(0, "LINE",
            "This object defines a beamline list with arguments.\n"
            "\t<name>(<args>);"),
      body("LINE") {}
 
LineTemplate::LineTemplate(const std::string& name, Object* parent)
    : Macro(name, parent), body(name) {}
 
LineTemplate::~LineTemplate() {}
 
LineTemplate* LineTemplate::clone(const std::string& /*name*/) {
    throw ParseError("LineTemplate::clone()", "You cannot use this object without attributes.");
}
 
Object* LineTemplate::makeInstance(const std::string& name, Statement& statement, const Parser*) {
    Line* instance = 0;
 
    try {
        // Parse actuals and check their number.
        parseActuals(statement);
        if (formals.size() != actuals.size()) {
            throw ParseError(
                    "LineTemplate::makeInstance()", "Inconsistent number of macro arguments.");
        }
 
        // Expand the LINE macro in token form.
        body.start();
        Token token = body.readToken();
        SimpleStatement expansion(getOpalName(), 1);
        while (!token.isEOF()) {
            bool found = false;
            if (token.isWord()) {
                std::string word = token.getWord();
 
                for (std::vector<std::string>::size_type i = 0; i < formals.size(); i++) {
                    if (word == formals[i]) {
                        std::vector<Token> act = actuals[i];
                        for (Token t : act) {
                            expansion.append(t);
                        }
                        found = true;
                        break;
                    }
                }
            }
            if (!found) expansion.append(token);
            token = body.readToken();
        }
 
        // Parse the modified line.
        Line* model = dynamic_cast<Line*>(OpalData::getInstance()->find("LINE"));
        instance    = model->clone(name);
        instance->copyAttributes(*this);
        expansion.start();
        instance->parse(expansion);
    } catch (...) {
        delete instance;
        throw;
    }
 
    return instance;
}
 
Object* LineTemplate::makeTemplate(const std::string&, TokenStream&, Statement&) {
    // Should not be called.
    return 0;
}
 
void LineTemplate::parseTemplate(TokenStream&, Statement& statement) {
    parseFormals(statement);
    bool isLine = statement.keyword("LINE");
    PAssert(isLine);
 
    // Store the template list.
    Token token = statement.getCurrent();
    if (token.isDel('=')) {
        body.append(token);
        int level = 0;
        while (!statement.atEnd()) {
            token = statement.getCurrent();
            if (token.isDel('(')) {
                level++;
            } else if (token.isDel(')')) {
                body.append(token);
                if (--level == 0) break;
            }
            body.append(token);
        }
    } else {
        throw ParseError("LineTemplate::parseTemplate()", "Equals sign '=' expected.");
    }
}