| /* |
| * 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 failable<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 failable<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 mkfailure<value>(); |
| logStream() << "Illegal lexical syntax '" << firstChar << "'" << endl; |
| return readToken(in); |
| } |
| |
| const failable<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 failable<value> ftoken = readToken(in); |
| if (!hasContent(ftoken)) |
| return reverse(listSoFar); |
| const value token = content(ftoken); |
| if(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) { |
| const value val = c_str(listToString(readIdentifierHelper(mklist(chr), in))); |
| if (val == "false") |
| return value((bool)false); |
| if (val == "true") |
| return value((bool)true); |
| if (val == "nil") |
| return value(); |
| return val; |
| } |
| |
| const list<char> readStringHelper(const list<char>& listSoFar, istream& in) { |
| const char nextChar = readChar(in); |
| if(nextChar == -1 || nextChar == '"') |
| return reverse(listSoFar); |
| if (nextChar == '\\') { |
| const char escapedChar = readChar(in); |
| if (escapedChar == -1) |
| return reverse(listSoFar); |
| return readStringHelper(cons(escapedChar, listSoFar), in); |
| } |
| return readStringHelper(cons(nextChar, listSoFar), in); |
| } |
| |
| 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 failable<value> fnextToken = readToken(in); |
| if (!hasContent(fnextToken)) |
| return value(); |
| const value nextToken = content(fnextToken); |
| if(isLeftParenthesis(nextToken)) |
| return readList(list<value>(), in); |
| return nextToken; |
| } |
| |
| const value readValue(const string s) { |
| istringstream in(s); |
| const failable<value> fnextToken = readToken(in); |
| if (!hasContent(fnextToken)) |
| return value(); |
| const value nextToken = content(fnextToken); |
| 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 */ |