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Diffstat (limited to 'docs')
| -rw-r--r-- | docs/contracts.rst | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/docs/contracts.rst b/docs/contracts.rst index dfdcaf18..d3a89c1e 100644 --- a/docs/contracts.rst +++ b/docs/contracts.rst @@ -195,45 +195,47 @@ return parameter list for functions. uint public data; } -An other contract ``D`` can call ``c.getData()`` to retrieve the value of data in state -storage and is not able to call ``f``. Contract ``E`` is derived from ``C`` and can call -``compute``. +In the following example, ``D``, can call ``c.getData()`` to retrieve the value of +``data`` in state storage, but is not able to call ``f``. Contract ``E`` is derived from +``C`` and, thus, can call ``compute``. :: contract C { + uint private data; + function f(uint a) private returns(uint b) { return a + 1; } function setData(uint a) { data = a; } - function getData() public returns(uint) {return data;} - function compute(uint a, uint b) internal returns (uint) { return a+b;} - uint private data; + function getData() public returns(uint) { return data; } + function compute(uint a, uint b) internal returns (uint) { return a+b; } } + contract D { function readData() { C c = new C(); - local = c.f(7); // error: member "f" is not visible + uint local = c.f(7); // error: member "f" is not visible c.setData(3); - uint local = c.getData(); - local = c.compute(3,5); // error: member "compute" is not visible + local = c.getData(); + local = c.compute(3, 5); // error: member "compute" is not visible } } + contract E is C { function g() { C c = new C(); - uint val = compute(3,5); // acces to internal member (from derivated to parent contract) + uint val = compute(3, 5); // acces to internal member (from derivated to parent contract) } } - .. index:: ! accessor;function, ! function;accessor Accessor Functions ================== The compiler automatically creates accessor functions for -all public state variables. For the contract given below the compiler will +all public state variables. For the contract given below, the compiler will generate a function called ``data`` that does not take any arguments and returns a ``uint``, the value of the state variable ``data``. The initialization of state variables can @@ -245,6 +247,7 @@ be done at declaration. uint public data = 42; } + contract Caller { C c = new C(); function f() { @@ -254,8 +257,8 @@ be done at declaration. The accessor functions have external visibility. If the symbol is accessed internally (i.e. without ``this.``), -it is evaluated as state variable and if it is accessed externally -(i.e. with ``this.``), it is evaluated as function. +it is evaluated as a state variable and if it is accessed externally +(i.e. with ``this.``), it is evaluated as a function. :: |