Add iostream to CTL

ctl/istringstream.cc

@@ -0,0 +1,221 @@
+// -*- mode:c++; indent-tabs-mode:nil; c-basic-offset:4; coding:utf-8 -*-
+// vi: set et ft=cpp ts=4 sts=4 sw=4 fenc=utf-8 :vi
+//
+// Copyright 2024 Justine Alexandra Roberts Tunney
+//
+// Permission to use, copy, modify, and/or distribute this software for
+// any purpose with or without fee is hereby granted, provided that the
+// above copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+// AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+// DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+// PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+// TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#include "istringstream.h"
+#include "libc/fmt/conv.h"
+#include "libc/str/str.h"
+
+namespace ctl {
+
+istringstream::istringstream() : buffer_(), read_pos_(0)
+{
+}
+
+istringstream::istringstream(const string_view& str)
+  : buffer_(str), read_pos_(0)
+{
+}
+
+string
+istringstream::str() const
+{
+    return buffer_;
+}
+
+void
+istringstream::str(const string& s)
+{
+    buffer_ = s;
+    read_pos_ = 0;
+    clear();
+}
+
+istringstream&
+istringstream::operator>>(char& c)
+{
+    if (good() && read_pos_ < buffer_.size()) {
+        c = buffer_[read_pos_++];
+    } else {
+        setstate(ios_base::failbit);
+    }
+    return *this;
+}
+
+istringstream&
+istringstream::operator>>(char* s)
+{
+    if (!good())
+        return *this;
+
+    while (read_pos_ < buffer_.size() && isspace(buffer_[read_pos_]))
+        ++read_pos_;
+
+    size_t start = read_pos_;
+    while (read_pos_ < buffer_.size() && !isspace(buffer_[read_pos_])) {
+        s[read_pos_ - start] = buffer_[read_pos_];
+        ++read_pos_;
+    }
+    s[read_pos_ - start] = '\0';
+
+    if (start == read_pos_) {
+        setstate(ios_base::failbit);
+    } else if (read_pos_ == buffer_.size()) {
+        setstate(ios_base::eofbit);
+    }
+
+    return *this;
+}
+
+istringstream&
+istringstream::operator>>(string& s)
+{
+    if (!good())
+        return *this;
+
+    s.clear();
+    while (read_pos_ < buffer_.size() && isspace(buffer_[read_pos_]))
+        ++read_pos_;
+
+    while (read_pos_ < buffer_.size() && !isspace(buffer_[read_pos_])) {
+        s.push_back(buffer_[read_pos_]);
+        ++read_pos_;
+    }
+
+    if (s.empty()) {
+        setstate(ios_base::failbit);
+    } else if (read_pos_ == buffer_.size()) {
+        setstate(ios_base::eofbit);
+    }
+
+    return *this;
+}
+
+template<typename T>
+istringstream&
+istringstream::read_numeric(T& value)
+{
+    if (!good())
+        return *this;
+
+    while (read_pos_ < buffer_.size() && isspace(buffer_[read_pos_]))
+        ++read_pos_;
+
+    // size_t start = read_pos_;
+    bool is_negative = false;
+    if (read_pos_ < buffer_.size() &&
+        (buffer_[read_pos_] == '-' || buffer_[read_pos_] == '+')) {
+        is_negative = (buffer_[read_pos_] == '-');
+        ++read_pos_;
+    }
+
+    T result = 0;
+    bool valid = false;
+    while (read_pos_ < buffer_.size() && isdigit(buffer_[read_pos_])) {
+        result = result * 10 + (buffer_[read_pos_] - '0');
+        ++read_pos_;
+        valid = true;
+    }
+
+    if (valid) {
+        value = is_negative ? -result : result;
+        if (read_pos_ == buffer_.size())
+            setstate(ios_base::eofbit);
+    } else {
+        setstate(ios_base::failbit);
+    }
+
+    return *this;
+}
+
+istringstream&
+istringstream::operator>>(short& n)
+{
+    return read_numeric(n);
+}
+
+istringstream&
+istringstream::operator>>(unsigned short& n)
+{
+    return read_numeric(n);
+}
+
+istringstream&
+istringstream::operator>>(int& n)
+{
+    return read_numeric(n);
+}
+
+istringstream&
+istringstream::operator>>(unsigned int& n)
+{
+    return read_numeric(n);
+}
+
+istringstream&
+istringstream::operator>>(long& n)
+{
+    return read_numeric(n);
+}
+
+istringstream&
+istringstream::operator>>(unsigned long& n)
+{
+    return read_numeric(n);
+}
+
+istringstream&
+istringstream::operator>>(float& f)
+{
+    if (!good())
+        return *this;
+
+    char* end;
+    f = strtof(buffer_.c_str() + read_pos_, &end);
+
+    if (end == buffer_.c_str() + read_pos_) {
+        setstate(ios_base::failbit);
+    } else {
+        read_pos_ = end - buffer_.c_str();
+        if (read_pos_ == buffer_.size())
+            setstate(ios_base::eofbit);
+    }
+
+    return *this;
+}
+
+istringstream&
+istringstream::operator>>(double& d)
+{
+    if (!good())
+        return *this;
+
+    char* end;
+    d = strtod(buffer_.c_str() + read_pos_, &end);
+
+    if (end == buffer_.c_str() + read_pos_) {
+        setstate(ios_base::failbit);
+    } else {
+        read_pos_ = end - buffer_.c_str();
+        if (read_pos_ == buffer_.size())
+            setstate(ios_base::eofbit);
+    }
+
+    return *this;
+}
+
+} // namespace ctl