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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
/* $Rev$ $Date$ */
#ifndef tuscany_scheme_io_hpp
#define tuscany_scheme_io_hpp
/**
* Script evaluator IO functions.
*/
#include <ctype.h>
#include "stream.hpp"
#include "string.hpp"
#include "list.hpp"
#include "value.hpp"
#include "primitive.hpp"
namespace tuscany {
namespace scheme {
const value rightParenthesis(mklist<value>(")"));
const value leftParenthesis(mklist<value>("("));
const value comment(mklist<value>(";"));
const double stringToNumber(const string& str) {
return atof(c_str(str));
}
const bool isWhitespace(const char ch) {
return ch != -1 && isspace(ch);
}
const bool isIdentifierStart(const char ch) {
return ch != -1 && !isspace(ch) && !isdigit(ch);
}
const bool isIdentifierPart(const char ch) {
return ch != -1 && !isspace(ch) && ch != '(' && ch != ')';
}
const bool isDigit(const char ch) {
return isdigit(ch) || ch == '.';
}
const bool isLeftParenthesis(const value& token) {
return leftParenthesis == token;
}
const bool isRightParenthesis(const value& token) {
return rightParenthesis == token;
}
const char readChar(istream& in) {
if(in.eof()) {
return -1;
}
char c = (char)get(in);
return c;
}
const char peekChar(istream& in) {
if(eof(in))
return -1;
char c = (char)peek(in);
return c;
}
const bool isQuote(const value& token) {
return token == quoteSymbol;
}
const value skipComment(istream& in);
const value readQuoted(istream& in);
const value readIdentifier(const char chr, istream& in);
const value readString(istream& in);
const value readNumber(const char chr, istream& in);
const value readValue(istream& in);
const value readToken(istream& in) {
const char firstChar = readChar(in);
if(isWhitespace(firstChar))
return readToken(in);
if(firstChar == ';')
return skipComment(in);
if(firstChar == '\'')
return readQuoted(in);
if(firstChar == '(')
return leftParenthesis;
if(firstChar == ')')
return rightParenthesis;
if(firstChar == '"')
return readString(in);
if(isIdentifierStart(firstChar))
return readIdentifier(firstChar, in);
if(isDigit(firstChar))
return readNumber(firstChar, in);
if(firstChar == -1)
return value();
logStream() << "Illegal lexical syntax '" << firstChar << "'" << endl;
return readToken(in);
}
const value skipComment(istream& in) {
const char nextChar = readChar(in);
if (nextChar == '\n')
return readToken(in);
return skipComment(in);
}
const value readQuoted(istream& in) {
return mklist(quoteSymbol, readValue(in));
}
const list<value> readList(const list<value>& listSoFar, istream& in) {
const value token = readToken(in);
if(isNil(token) || isRightParenthesis(token))
return reverse(listSoFar);
if(isLeftParenthesis(token))
return readList(cons(value(readList(list<value> (), in)), listSoFar), in);
return readList(cons(token, listSoFar), in);
}
const string listToString(const list<char>& l) {
if(isNil(l))
return "";
const char buf[1] = { car(l) };
return string(buf, 1) + listToString(cdr(l));
}
const list<char> readIdentifierHelper(const list<char>& listSoFar, istream& in) {
const char nextChar = peekChar(in);
if(isIdentifierPart(nextChar))
return readIdentifierHelper(cons(readChar(in), listSoFar), in);
return reverse(listSoFar);
}
const value readIdentifier(const char chr, istream& in) {
return c_str(listToString(readIdentifierHelper(mklist(chr), in)));
}
const list<char> readStringHelper(const list<char>& listSoFar, istream& in) {
const char nextChar = readChar(in);
if(nextChar != -1 && nextChar != '"')
return readStringHelper(cons(nextChar, listSoFar), in);
return reverse(listSoFar);
}
const value readString(istream& in) {
return listToString(readStringHelper(list<char>(), in));
}
const list<char> readNumberHelper(const list<char>& listSoFar, istream& in) {
const char nextChar = peekChar(in);
if(isDigit(nextChar))
return readNumberHelper(cons(readChar(in), listSoFar), in);
return reverse(listSoFar);
}
const value readNumber(const char chr, istream& in) {
return stringToNumber(listToString(readNumberHelper(mklist(chr), in)));
}
const value readValue(istream& in) {
const value nextToken = readToken(in);
if(isLeftParenthesis(nextToken))
return readList(list<value> (), in);
return nextToken;
}
const value readValue(const string s) {
istringstream in(s);
const value nextToken = readToken(in);
if(isLeftParenthesis(nextToken))
return readList(list<value> (), in);
return nextToken;
}
const bool writeValue(const value& val, ostream& out) {
out << val;
return true;
}
const string writeValue(const value& val) {
ostringstream out;
out << val;
return str(out);
}
const value readScript(istream& in) {
const value val = readValue(in);
if (isNil(val))
return list<value>();
return cons(val, (list<value>)readScript(in));
}
}
}
#endif /* tuscany_scheme_io_hpp */
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