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++ // Copyright 2009-2021 Intel Corporation
++ // SPDX-License-Identifier: Apache-2.0
++
++ #include "tokenstream.h"
++ #include "../math/math.h"
++
++ namespace embree
++ {
++ /* shorthands for common sets of characters */
++ const std::string TokenStream::alpha = "abcdefghijklmnopqrstuvwxyz";
++ const std::string TokenStream::ALPHA = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
++ const std::string TokenStream::numbers = "0123456789";
++ const std::string TokenStream::separators = "\n\t\r ";
++ const std::string TokenStream::stringChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 _.,+-=:/*\\";
++
++ /* creates map for fast categorization of characters */
++ static void createCharMap(bool map[256], const std::string& chrs) {
++ for (size_t i=0; i<256; i++) map[i] = false;
++ for (size_t i=0; i<chrs.size(); i++) map[uint8_t(chrs[i])] = true;
++ }
++
++ /* build full tokenizer that takes list of valid characters and keywords */
++ TokenStream::TokenStream(const Ref<Stream<int> >& cin, //< stream to read from
++ const std::string& alpha, //< valid characters for identifiers
++ const std::string& seps, //< characters that act as separators
++ const std::vector<std::string>& symbols) //< symbols
++ : cin(cin), symbols(symbols)
++ {
++ createCharMap(isAlphaMap,alpha);
++ createCharMap(isSepMap,seps);
++ createCharMap(isStringCharMap,stringChars);
++ }
++
++ bool TokenStream::decDigits(std::string& str_o)
++ {
++ bool ok = false;
++ std::string str;
++ if (cin->peek() == '+' || cin->peek() == '-') str += (char)cin->get();
++ while (isDigit(cin->peek())) { ok = true; str += (char)cin->get(); }
++ if (ok) str_o += str;
++ else cin->unget(str.size());
++ return ok;
++ }
++
++ bool TokenStream::decDigits1(std::string& str_o)
++ {
++ bool ok = false;
++ std::string str;
++ while (isDigit(cin->peek())) { ok = true; str += (char)cin->get(); }
++ if (ok) str_o += str; else cin->unget(str.size());
++ return ok;
++ }
++
++ bool TokenStream::trySymbol(const std::string& symbol)
++ {
++ size_t pos = 0;
++ while (pos < symbol.size()) {
++ if (symbol[pos] != cin->peek()) { cin->unget(pos); return false; }
++ cin->drop(); pos++;
++ }
++ return true;
++ }
++
++ bool TokenStream::trySymbols(Token& token, const ParseLocation& loc)
++ {
++ for (size_t i=0; i<symbols.size(); i++) {
++ if (!trySymbol(symbols[i])) continue;
++ token = Token(symbols[i],Token::TY_SYMBOL,loc);
++ return true;
++ }
++ return false;
++ }
++
++ bool TokenStream::tryFloat(Token& token, const ParseLocation& loc)
++ {
++ bool ok = false;
++ std::string str;
++ if (trySymbol("nan")) {
++ token = Token(float(nan));
++ return true;
++ }
++ if (trySymbol("+inf")) {
++ token = Token(float(pos_inf));
++ return true;
++ }
++ if (trySymbol("-inf")) {
++ token = Token(float(neg_inf));
++ return true;
++ }
++
++ if (decDigits(str))
++ {
++ if (cin->peek() == '.') {
++ str += (char)cin->get();
++ decDigits(str);
++ if (cin->peek() == 'e' || cin->peek() == 'E') {
++ str += (char)cin->get();
++ if (decDigits(str)) ok = true; // 1.[2]E2
++ }
++ else ok = true; // 1.[2]
++ }
++ else if (cin->peek() == 'e' || cin->peek() == 'E') {
++ str += (char)cin->get();
++ if (decDigits(str)) ok = true; // 1E2
++ }
++ }
++ else
++ {
++ if (cin->peek() == '.') {
++ str += (char)cin->get();
++ if (decDigits(str)) {
++ if (cin->peek() == 'e' || cin->peek() == 'E') {
++ str += (char)cin->get();
++ if (decDigits(str)) ok = true; // .3E2
++ }
++ else ok = true; // .3
++ }
++ }
++ }
++ if (ok) {
++ token = Token((float)atof(str.c_str()),loc);
++ }
++ else cin->unget(str.size());
++ return ok;
++ }
++
++ bool TokenStream::tryInt(Token& token, const ParseLocation& loc) {
++ std::string str;
++ if (decDigits(str)) {
++ token = Token(atoi(str.c_str()),loc);
++ return true;
++ }
++ return false;
++ }
++
++ bool TokenStream::tryString(Token& token, const ParseLocation& loc)
++ {
++ std::string str;
++ if (cin->peek() != '\"') return false;
++ cin->drop();
++ while (cin->peek() != '\"') {
++ const int c = cin->get();
++ if (!isStringChar(c)) THROW_RUNTIME_ERROR("invalid string character "+std::string(1,c)+" at "+loc.str());
++ str += (char)c;
++ }
++ cin->drop();
++ token = Token(str,Token::TY_STRING,loc);
++ return true;
++ }
++
++ bool TokenStream::tryIdentifier(Token& token, const ParseLocation& loc)
++ {
++ std::string str;
++ if (!isAlpha(cin->peek())) return false;
++ str += (char)cin->get();
++ while (isAlphaNum(cin->peek())) str += (char)cin->get();
++ token = Token(str,Token::TY_IDENTIFIER,loc);
++ return true;
++ }
++
++ void TokenStream::skipSeparators()
++ {
++ /* skip separators */
++ while (cin->peek() != EOF && isSeparator(cin->peek()))
++ cin->drop();
++ }
++
++ Token TokenStream::next()
++ {
++ Token token;
++ skipSeparators();
++ ParseLocation loc = cin->loc();
++ if (trySymbols (token,loc)) return token; /**< try to parse a symbol */
++ if (tryFloat (token,loc)) return token; /**< try to parse float */
++ if (tryInt (token,loc)) return token; /**< try to parse integer */
++ if (tryString (token,loc)) return token; /**< try to parse string */
++ if (tryIdentifier(token,loc)) return token; /**< try to parse identifier */
++ if (cin->peek() == EOF ) return Token(loc); /**< return EOF token */
++ return Token((char)cin->get(),loc); /**< return invalid character token */
++ }
++ }