Initial import

format.cc

@@ -0,0 +1,184 @@
+/*
+ Small, safe and fast printf-like formatting library for C++
+ Author: Victor Zverovich
+ */
+
+#include "format.h"
+
+#include <cassert>
+#include <cstring>
+#include <algorithm>
+
+using std::size_t;
+
+template <typename T>
+void fmt::Formatter::FormatArg(
+    const char *format, const T &arg, int width, int precision) {
+  size_t offset = buffer_.size();
+  buffer_.resize(buffer_.capacity());
+  for (;;) {
+    size_t size = buffer_.size() - offset;
+    int n = 0;
+    if (width < 0) {
+      n = precision < 0 ?
+          snprintf(&buffer_[offset], size, format, arg) :
+          snprintf(&buffer_[offset], size, format, precision, arg);
+    } else {
+      n = precision < 0 ?
+          snprintf(&buffer_[offset], size, format, width, arg) :
+          snprintf(&buffer_[offset], size, format, width, precision, arg);
+    }
+    if (n >= 0 && offset + n < buffer_.size()) {
+      buffer_.resize(offset + n);
+      return;
+    }
+    buffer_.resize(n >= 0 ? offset + n + 1 : 2 * buffer_.size());
+  }
+}
+
+void fmt::Formatter::Format() {
+  buffer_.reserve(500);
+  const char *start = format_;
+  const char *s = start;
+  for (; *s; ++s) {
+    if (*s != '{') continue;
+    buffer_.insert(buffer_.end(), start, s);
+    ++s;
+
+    // Parse argument index.
+    unsigned arg_index = 0;
+    if ('0' <= *s && *s <= '9') {
+      do {
+        arg_index = arg_index * 10 + (*s++ - '0');
+      } while ('0' <= *s && *s <= '9');
+    } else {
+      throw FormatError("missing argument index in format string");
+    }
+    // TODO: check if argument index is correct
+
+    char arg_format[8];  // longest format: %+0*.*ld
+    char *arg_format_ptr = arg_format;
+    *arg_format_ptr++ = '%';
+
+    char type = 0;
+    int width = -1;
+    int precision = -1;
+    if (*s == ':') {
+      ++s;
+      if (*s == '+')
+        *arg_format_ptr++ = *s++;
+      if (*s == '0')
+        *arg_format_ptr++ = *s++;
+
+      // Parse width.
+      if ('0' <= *s && *s <= '9') {
+        *arg_format_ptr++ = '*';
+        width = 0;
+        do {
+          width = width * 10 + (*s++ - '0');
+        } while ('0' <= *s && *s <= '9');
+      }
+
+      // Parse precision.
+      if (*s == '.') {
+        *arg_format_ptr++ = '.';
+        *arg_format_ptr++ = '*';
+        ++s;
+        precision = 0;
+        if ('0' <= *s && *s <= '9') {
+          do {
+            precision = precision * 10 + (*s++ - '0');
+          } while ('0' <= *s && *s <= '9');
+        } else {
+          // TODO: error
+        }
+      }
+
+      // Parse type.
+      if (*s == 'f' || *s == 'g')
+        type = *s++; // TODO: check if the type matches
+    }
+
+    if (*s++ != '}')
+      throw FormatError("single '{' encountered in format string");
+    start = s;
+
+    // Format argument.
+    Arg &arg = args_[arg_index];
+    switch (arg.type) {
+    case CHAR:
+      if (width == -1 && precision == -1) {
+        buffer_.push_back(arg.int_value);
+        break;
+      }
+      *arg_format_ptr++ = 'c';
+      *arg_format_ptr = '\0';
+      FormatArg(arg_format, arg.int_value, width, precision);
+      break;
+    case INT:
+      *arg_format_ptr++ = 'd';
+      *arg_format_ptr = '\0';
+      FormatArg(arg_format, arg.int_value, width, precision);
+      break;
+    case UINT:
+      *arg_format_ptr++ = 'd';
+      *arg_format_ptr = '\0';
+      FormatArg(arg_format, arg.uint_value, width, precision);
+      break;
+    case LONG:
+      *arg_format_ptr++ = 'l';
+      *arg_format_ptr++ = 'd';
+      *arg_format_ptr = '\0';
+      FormatArg(arg_format, arg.long_value, width, precision);
+      break;
+    case ULONG:
+      *arg_format_ptr++ = 'l';
+      *arg_format_ptr++ = 'd';
+      *arg_format_ptr = '\0';
+      FormatArg(arg_format, arg.ulong_value, width, precision);
+      break;
+    case DOUBLE:
+      *arg_format_ptr++ = type ? type : 'g';
+      *arg_format_ptr = '\0';
+      FormatArg(arg_format, arg.double_value, width, precision);
+      break;
+    case LONG_DOUBLE:
+      *arg_format_ptr++ = 'l';
+      *arg_format_ptr++ = 'g';
+      *arg_format_ptr = '\0';
+      FormatArg(arg_format, arg.long_double_value, width, precision);
+      break;
+    case STRING:
+      if (width == -1 && precision == -1) {
+        const char *str = arg.string_value;
+        buffer_.insert(buffer_.end(), str, str + std::strlen(str));
+        break;
+      }
+      *arg_format_ptr++ = 's';
+      *arg_format_ptr = '\0';
+      FormatArg(arg_format, arg.string_value, width, precision);
+      break;
+    case WSTRING:
+      *arg_format_ptr++ = 'l';
+      *arg_format_ptr++ = 's';
+      *arg_format_ptr = '\0';
+      FormatArg(arg_format, arg.wstring_value, width, precision);
+      break;
+    case POINTER:
+      *arg_format_ptr++ = 'p';
+      *arg_format_ptr = '\0';
+      FormatArg(arg_format, arg.pointer_value, width, precision);
+      break;
+    default:
+      assert(false);
+      break;
+    }
+  }
+  buffer_.insert(buffer_.end(), start, s + 1);
+}
+
+fmt::ArgFormatter::~ArgFormatter() {
+  if (!formatter_) return;
+  FinishFormatting();
+}
+