From 7d7dad1e70da5866a319b0e7b24e97304c3696ea Mon Sep 17 00:00:00 2001
From: Konstantin Nazarov <mail@knazarov.com>
Date: Tue, 2 Jul 2024 23:59:04 +0100
Subject: [PATCH] First example of counter contract for Nil

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 README.md     |  3 ++
 contracts.org | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+)
 create mode 100644 README.md
 create mode 100644 contracts.org

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+# Literate examples for Nil
+
+It's a collection of executable org-mode files that demonstrate how to write different kinds of smart contracts for Nil.
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+#+title: Playing with smart contracts in org-mode
+
+* Simple counter contract in Solidity
+
+Nothing fancy really. A function to increment a value,
+and a function to read a value.
+
+#+name: simple_storage
+#+begin_example solidity
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+contract SimpleStorage {
+    int32 private value;
+
+    function increment() public {
+        value += 1;
+    }
+
+    function get() public view returns(int32) {
+        return value;
+    }
+}
+#+end_example
+
+* Compile the contract
+
+Using off-the-shelf ~solc~, the default Solidity compiler.
+We feed in the code from the previous slide.
+
+#+begin_src bash :var contract=simple_storage
+mkdir -p contract
+echo "$contract" | solc -o contract/ --bin --abi --overwrite -
+#+end_src
+
+
+* Initialize the config and create a wallet
+
+Because without a wallet we are powerless.
+
+#+name: wallet
+#+begin_src bash
+mkdir -p ~/.config/nil/
+rm -rf ~/.config/nil/*
+touch ~/.config/nil/config.yaml
+
+nil_cli config set rpc_endpoint "http://127.0.0.1:8529" 2> /dev/null
+nil_cli keygen new 2> /dev/null
+nil_cli wallet new 2> /dev/null
+
+wallet=$(nil_cli wallet info 2>&1 | grep -oP 'Address: \K\w+')
+echo $wallet
+#+end_src
+
+* Top-up the wallet
+
+Gimme some tokens. Display new balance.
+
+#+begin_src bash
+nil_cli wallet top-up 100000000 2> /dev/null
+nil_cli wallet balance 2>&1 | grep -oP 'balance: \K\w+'
+#+end_src
+
+* Deploy the contract
+
+Save the address and reuse it later.
+
+#+name: contract
+#+begin_src bash
+nil_cli wallet deploy ./contract/SimpleStorage.bin 2>&1 | grep -oP 'address: \K\w+'
+#+end_src
+
+* Call the contract
+
+Notice that we use ~$address~ from the previous execution of ~nil_cli~.
+
+#+begin_src bash :var address=contract
+nil_cli wallet send-message "$address" increment --abi ./contract/SimpleStorage.abi 2>&1 | grep -oP 'Transaction hash: \K\w+'
+#+end_src
+
+#+begin_src bash :var address=contract
+nil_cli contract call-readonly "$address" get --abi ./contract/SimpleStorage.abi 2>&1 | grep -oP 'Call result: \K\w+'
+#+end_src