feat(string): add SStrPrintf

storm/String.cpp

@@ -4,6 +4,8 @@
 #include "storm/string/bjhash.hpp"
 #include <cctype>
 #include <cmath>
+#include <cstdarg>
+#include <cstdio>
 #include <cstring>
 #include <strings.h>
 
@@ -167,6 +169,29 @@ void InitializeFloatDigits() {
     }
 }
 
+size_t ISStrVPrintf(const char* format, va_list va, char* dest, size_t maxchars) {
+    if (!maxchars) {
+        return 0;
+    }
+
+    size_t result;
+
+    if (maxchars == STORM_MAX_STR) {
+        // TODO conditional vsoprintf;
+        result = vsprintf(dest, format, va);
+    } else {
+        // TODO conditional vsnoprintf;
+        result = vsnprintf(dest, maxchars, format, va);
+
+        if (result >= maxchars) {
+            result = maxchars - 1;
+            dest[result] = '\0';
+        }
+    }
+
+    return result;
+}
+
 void SStrInitialize() {
     if (!s_initialized) {
         InitializeFloatDigits();
@@ -347,6 +372,16 @@ uint32_t SStrPack(char* dest, const char* source, uint32_t destsize) {
     return i - dest;
 }
 
+size_t SStrPrintf(char* dest, size_t maxchars, const char* format, ...) {
+    va_list va;
+    va_start(va, format);
+
+    STORM_ASSERT(dest);
+    STORM_ASSERT(format);
+
+    return ISStrVPrintf(format, va, dest, maxchars);
+}
+
 const char* SStrStr(const char* string, const char* search) {
     STORM_ASSERT(string);
     STORM_ASSERT(search);

storm/String.hpp

@@ -27,6 +27,8 @@ void SStrLower(char* string);
 
 uint32_t SStrPack(char* dest, const char* source, uint32_t destsize);
 
+size_t SStrPrintf(char* dest, size_t maxchars, const char* format, ...);
+
 const char* SStrStr(const char* string, const char* search);
 
 void SStrTokenize(const char** string, char* buffer, size_t bufferchars, const char* whitespace, int32_t* quoted);

test/String.cpp

@@ -207,6 +207,24 @@ TEST_CASE("SStrPack", "[string]") {
     }
 }
 
+TEST_CASE("SStrPrintf", "[string]") {
+    SECTION("fills dest with formatted string") {
+        char dest[100] = { 0 };
+        auto format = "%s - %s";
+        auto length = SStrPrintf(dest, 100, format, "foo", "bar");
+        REQUIRE(length == 9);
+        REQUIRE(!SStrCmp(dest, "foo - bar", SStrLen("foo - bar")));
+    }
+
+    SECTION("fills dest with empty string") {
+        char dest[100] = { 0 };
+        auto format = "";
+        auto length = SStrPrintf(dest, 100, format);
+        REQUIRE(length == 0);
+        REQUIRE(!SStrCmp(dest, "", SStrLen("")));
+    }
+}
+
 TEST_CASE("SStrStr", "[string]") {
     SECTION("finds substring when it exists at end of string") {
         auto string = "foobar";