Merge pull request #1411 from ethereum/function-type-docs

Fix function type examples

1 files changed, 18 insertions, 8 deletions

diff --git a/docs/types.rst b/docs/types.rst
index b22ad7d4..1db35ced 100644
--- a/docs/types.rst
+++ b/docs/types.rst
@@ -312,12 +312,19 @@ If external function types are used outside of the context of Solidity,
 they are treated as the ``function`` type, which encodes the address
 followed by the function identifier together in a single ``bytes24`` type.
 
+Note that public functions of the current contract can be used both as an
+internal and as an external function. To use ``f`` as an internal function,
+just use ``f``, if you want to use its external form, use ``this.f``.
+
 Example that shows how to use internal function types::
 
+    pragma solidity ^0.4.5;
+
     library ArrayUtils {
       // internal functions can be used in internal library functions because
       // they will be part of the same code context
       function map(uint[] memory self, function (uint) returns (uint) f)
+        internal
         returns (uint[] memory r)
       {
         r = new uint[](self.length);
@@ -327,8 +334,9 @@ Example that shows how to use internal function types::
       }
       function reduce(
         uint[] memory self,
-        function (uint) returns (uint) f
+        function (uint x, uint y) returns (uint) f
       )
+        internal
         returns (uint r)
       {
         r = self[0];
@@ -336,7 +344,7 @@ Example that shows how to use internal function types::
           r = f(r, self[i]);
         }
       }
-      function range(uint length) returns (uint[] memory r) {
+      function range(uint length) internal returns (uint[] memory r) {
         r = new uint[](length);
         for (uint i = 0; i < r.length; i++) {
           r[i] = i;
@@ -346,7 +354,7 @@ Example that shows how to use internal function types::
     
     contract Pyramid {
       using ArrayUtils for *;
-      function pyramid(uint l) return (uint) {
+      function pyramid(uint l) returns (uint) {
         return ArrayUtils.range(l).map(square).reduce(sum);
       }
       function square(uint x) internal returns (uint) {
@@ -359,14 +367,16 @@ Example that shows how to use internal function types::
 
 Another example that uses external function types::
 
+    pragma solidity ^0.4.5;
+
     contract Oracle {
       struct Request {
         bytes data;
-        function(bytes) external callback;
+        function(bytes memory) external callback;
       }
       Request[] requests;
       event NewRequest(uint);
-      function query(bytes data, function(bytes) external callback) {
+      function query(bytes data, function(bytes memory) external callback) {
         requests.push(Request(data, callback));
         NewRequest(requests.length - 1);
       }
@@ -377,12 +387,12 @@ Another example that uses external function types::
     }
 
     contract OracleUser {
-      Oracle constant oracle = 0x1234567; // known contract
+      Oracle constant oracle = Oracle(0x1234567); // known contract
       function buySomething() {
-        oracle.query("USD", oracleResponse);
+        oracle.query("USD", this.oracleResponse);
       }
       function oracleResponse(bytes response) {
-        if (msg.sender != oracle) throw;
+        if (msg.sender != address(oracle)) throw;
         // Use the data
       }
     }