fixes on describe

run.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+
+BOLD="\033[1m"
+RESET="\033[0m"
+
+SUCCESS="\033[38;2;80;220;100m"
+FAIL="\033[38;2;255;90;90m"
+INFO="\033[38;2;100;200;255m"
+DIM="\033[2m"
+
+LOG="./out/out.log"
+
+# Start
+printf "${DIM}────────────────────────────────────────${RESET}\n"
+printf "${INFO}${BOLD}> Running...${RESET}\n"
+printf "${DIM}────────────────────────────────────────${RESET}\n\n"
+
+# Send both stdout and stderr to the console and the log file.
+start=$(date +%s.%N)
+./out/out "$@" 2>&1 | tee "$LOG"
+status=${PIPESTATUS[0]}
+end=$(date +%s.%N)
+elapsed=$(awk "BEGIN { printf \"%.3f\", $end - $start }")
+
+# Status!
+printf "\n${DIM}────────────────────────────────────────${RESET}\n"
+if (( status == 0 )); then
+    printf "${SUCCESS}${BOLD}✓ Success${RESET}  (exit %d)\n" "$status"
+else
+    printf "${FAIL}${BOLD}✗ Failed${RESET}   (exit %d)\n" "$status"
+fi
+printf "${INFO}${BOLD}> Time${RESET}     ${elapsed}s\n"
+printf "${INFO}${BOLD}> Log${RESET}      %s\n" "$LOG"
+printf "${DIM}────────────────────────────────────────${RESET}"
+exit "$status"

src/bigmath/BigMath.cpp

@@ -8,15 +8,8 @@
 using namespace bigmath;
 
 int main() {
-    segment s;
-    s.set(0, 8);
-    s.set(1, 5);
-    s.set(2, 5);
-
-    s.set(125, 8);
-    s.set(126, 1);
-    s.set(127, 2);
+    segment s(~u64(0));
     buffers::hexdump(data_view(s.bytes(), segment::byte_count), std::cout);
     std::cout << std::endl;
-    std::cout << s.describe() << std::endl;
+    std::cout << std::string(s) << std::endl;
 }

src/bigmath/chain/segment.cpp

@@ -1,7 +1,6 @@
 #include "segment.hpp"
 
-#include <sstream>
-#include <iomanip>
+#include <bigmath/util/describe.hpp>
 
 namespace bigmath {
 
@@ -10,6 +9,15 @@ namespace bigmath {
 
     segment::segment() : digits{} {}
 
+    segment::segment(u64 n) : segment() {
+        u8 i = 0;
+        while (n) {
+            u8 d10 = u8(n % 10);
+            n /= 10;
+            this->set(i++, d10);
+        }
+    }
+
     segment::~segment() {}
 
     u8 segment::operator[](u8 i) const {
@@ -32,44 +40,8 @@ namespace bigmath {
         return digits;
     }
 
-    std::string segment::describe() const {
-        std::ostringstream out;
-
-        // We'll iterate backwards
-        isize i = digit_count;
-        u32 use_space = 0;
-        while (i > 0) {
-            u8 val = operator[](u8(i - 1));
-
-            // Count repetitions
-            isize count = 1;
-            while (i > count && operator[](u8(i - count - 1)) == val) ++count;
-
-            // temporal string
-            std::ostringstream one;
-            one << u32(val);
-            auto str = one.str();
-
-            // Decide whether to compress
-            if (count > 5) {
-                if(use_space) out << " ";
-                out << "[" << str << " x " << count << "]";
-                use_space = 4;
-            } else {
-                for (isize j = 0; j < count; ++j) {
-                    if(use_space > 3) {
-                        out << " ";
-                        use_space = 1;
-                    }
-                    use_space++;
-                    out << str;
-                }
-            }
-
-            i -= count;
-        }
-
-        return out.str();
+    segment::operator std::string() const {
+        return describe(*this);
     }
 
 }

src/bigmath/chain/segment.hpp

@@ -21,6 +21,8 @@ namespace bigmath {
 
         segment();
 
+        segment(u64 n);
+
         ~segment();
 
     public:
@@ -33,7 +35,7 @@ namespace bigmath {
 
         const u8* bytes() const;
 
-        std::string describe() const;
+        operator std::string() const;
 
     };
 

src/bigmath/util/describe.cpp

@@ -0,0 +1,71 @@
+#include "describe.hpp"
+
+#include <bigmath/chain/segment.hpp>
+
+#include <sstream>
+#include <iomanip>
+#include <charconv>
+#include <algorithm>
+
+namespace bigmath {
+
+    std::string describe(const segment& s) {
+        std::string buf;
+        buf.reserve(segment::digit_count * 2);
+        u32 group_count = 0;
+
+        isize i = 0;
+        while (i < segment::digit_count) {
+            u8 val = s[static_cast<u8>(i)];
+
+            // Count repetitions
+            isize count = 1;
+            while (i + count < segment::digit_count && s[static_cast<u8>(i + count)] == val) {
+                ++count;
+            }
+
+            if (count > 5) {
+                if (!buf.empty() && buf.back() != ' ') {
+                    buf.push_back(' ');
+                }
+
+                // Append reversed tag directly: "]count x val["
+                buf.push_back(']');
+
+                // Fast reverse-append for count digits without heap allocation
+                isize temp_count = count;
+                do {
+                    buf.push_back(static_cast<char>('0' + (temp_count % 10)));
+                    temp_count /= 10;
+                } while (temp_count > 0);
+
+                buf.append(" x ");
+                buf.push_back(static_cast<char>('0' + val));
+                buf.push_back('[');
+
+                buf.push_back(' ');
+                group_count = 0;
+            } else {
+                char ch = static_cast<char>('0' + val);
+                for (isize j = 0; j < count; ++j) {
+                    if (group_count == 3) {
+                        buf.push_back(' ');
+                        group_count = 0;
+                    }
+                    buf.push_back(ch);
+                    group_count++;
+                }
+            }
+
+            i += count;
+        }
+
+        if (!buf.empty() && buf.back() == ' ') {
+            buf.pop_back();
+        }
+
+        std::reverse(buf.begin(), buf.end());
+        return buf;
+    }
+
+}

src/bigmath/util/describe.hpp

@@ -0,0 +1,9 @@
+#pragma once
+
+#include <bigmath/BigMath.hpp>
+
+namespace bigmath {
+
+    std::string describe(const segment& s);
+
+}