Strings experimenting

Custom string libraries, practicing string manipulation

Author: setzeus

Strings.sol

@@ -0,0 +1,50 @@
+pragma solidity ^0.4.9;
+
+library Strings {
+    function concact(string _base, string _value) internal returns(string) {
+        bytes memory _baseBytes = bytes(_base);
+        bytes memory _valueBytes = bytes(_value);
+        
+        string memory _tmpValue = new string(_baseBytes.length + _valueBytes.length);
+        bytes memory _newValue = bytes(_tmpValue);
+        
+        uint i;
+        uint j;
+        for(i=0;i<_baseBytes.length;i++) {
+            _newValue[j++] = _baseBytes[i];
+        }
+        for(i=0;i<_valueBytes.length;i++) {
+            _newValue[j++] = _valueBytes[i];
+        }
+        
+        return string(_newValue);
+        
+    }
+    
+    function strpos(string _base, string _value) internal returns (int) {
+        bytes memory _baseBytes = bytes(_base);
+        bytes memory _valueBytes = bytes(_value);
+        
+        assert(_valueBytes.length == 1);
+        
+        for(uint i=0;i<_baseBytes.length;i++) {
+            if(_baseBytes[i] == _valueBytes[0]) {
+                return int(i);
+            }
+        }
+        
+        return -1;
+    }
+}
+
+contract testString {
+    using Strings for string;
+    
+    function testConcact(string _base) returns (string) {
+        return _base.concact("_suffix");
+    }
+    
+    function needleInHaystack(string _base) returns (int) {
+        return _base.strpos("t");
+    }
+}