diff --git a/core.c b/core.c
index 6894c14..ff4f378 100644
--- a/core.c
+++ b/core.c
@@ -176,6 +176,10 @@ string strSlice(string str, size_t start, size_t stop) {
     };
 }
 
+inline string strChopStart(string str, size_t start) {
+    return strSlice(str, start, str.length);
+}
+
 string strListJoin(Arena *arena, StringList list) {
     string result = PushString(arena, 0);
     for (EachEl(list, string, item)) {
@@ -252,7 +256,7 @@ StringList strSplit(Arena *arena, string splitStr, string inputStr) {
     return result;
 }
 
-Int32Result parsePositiveInt(string str) {
+Int32Result parsePositiveInt32(string str) {
     size_t numEnd = 0;
     char currChar = str.str[numEnd];
     while (numEnd < str.length && isNumeric(currChar)) {
@@ -271,6 +275,25 @@ Int32Result parsePositiveInt(string str) {
     }
 }
 
+Int64Result parsePositiveInt64(string str) {
+    size_t numEnd = 0;
+    char currChar = str.str[numEnd];
+    while (numEnd < str.length && isNumeric(currChar)) {
+        numEnd++;
+        currChar = str.str[numEnd];
+    }
+    if (numEnd > 0) {
+        uint64 result = 0;
+        for (size_t i = 0; i < numEnd; i++) {
+            result *= 10;
+            result += str.str[i] - '0';
+        }
+        return (Int64Result){ .result=result, .valid=true };
+    } else {
+        return (Int64Result){ .result=0, .valid=false};
+    }
+}
+
 Real32Result parsePositiveReal32(string str) {
     Real32Result result = { .result=NAN, .valid=false};
 
@@ -291,8 +314,8 @@ Real32Result parsePositiveReal32(string str) {
         c++;
     }
     if (split) {
-        Int32Result wholePartParsed = parsePositiveInt(wholePartStr);
-        Int32Result fractionalPartParsed = parsePositiveInt(fractionalPartStr);
+        Int32Result wholePartParsed = parsePositiveInt32(wholePartStr);
+        Int32Result fractionalPartParsed = parsePositiveInt32(fractionalPartStr);
         if (wholePartParsed.valid && fractionalPartParsed.valid) {
             // TODO(dledda): implement powf with intrinsics? or just custom
             real32 fractionalPartMultiplier = 1.0f / powf(10.0f, (real32)fractionalPartStr.length);
@@ -300,7 +323,7 @@ Real32Result parsePositiveReal32(string str) {
             result.valid = true;
         }
     } else if (c > 0) {
-        Int32Result intPartParsed = parsePositiveInt(str);
+        Int32Result intPartParsed = parsePositiveInt32(str);
         if (intPartParsed.valid) {
             result.result = (real32)intPartParsed.result;
             result.valid = true;
diff --git a/core.h b/core.h
index a9dfa52..e5315b0 100644
--- a/core.h
+++ b/core.h
@@ -229,6 +229,7 @@ bool strContains(string a, string b);
 
 string strReverse(Arena *arena, string str);
 string strSlice(string str, size_t start, size_t stop);
+string strChopStart(string str, size_t start);
 string strSliceCStr(char *data, size_t start, size_t stop);
 StringList strSplit(Arena *arena, string splitStr, string inputStr);
 string strPrintfv(Arena *arena, const char *fmt, va_list args);
@@ -245,13 +246,12 @@ string strListJoin(Arena *arena, StringList list);
     typedef type prefix ## Result ## _underlying
 
 DefineResult(int32, Int32);
-Int32Result parsePositiveInt(string str);
-
+Int32Result parsePositiveInt32(string str);
+DefineResult(int64, Int64);
+Int64Result parsePositiveInt64(string str);
 DefineResult(real32, Real32);
 Real32Result parsePositiveReal32(string str);
 
-inline function bool isNumeric(char c);
-
 // ### Cmdline ###
 StringList getArgs(Arena *arena, int argc, char **argv);