feat: JSON reading

- Implemented a tokenizer for json
- Implemented a method which will read json from a string using the tokenizer

1 files changed, 61 insertions, 0 deletions

diff --git a/src/json.cpp b/src/json.cpp
index c11ca6e..9c1c3f9 100644
--- a/src/json.cpp
+++ b/src/json.cpp
@@ -1,7 +1,10 @@
 #include "json.h"
+#include "tokenizer.h"
 
 #include <cstddef>
+#include <iostream>
 #include <stdexcept>
+#include <string>
 
 namespace TehJSON
 {
@@ -66,4 +69,62 @@ namespace TehJSON
 			throw std::runtime_error("Node is a leaf!");
 		return children.size();
 	}
+
+	Token JSON::consume()
+	{
+		if(tokenPos >= tokens.size())
+			throw std::out_of_range("No tokens left, but json not finished!");
+		return tokens[tokenPos++];
+	}
+
+	Token JSON::consume(TokenType type)
+	{
+		Token t = consume();
+		if(t.type != type)
+			throw std::runtime_error("Wrong token type, expected: " + getTokenName(type) + ", but got: " + getTokenName(t.type));
+		return t;
+	}
+	
+	TokenType JSON::nextTokenType()
+	{
+		if(tokenPos >= tokens.size())
+			throw std::out_of_range("No tokens left, but json not finished!");
+		return tokens[tokenPos].type;
+	}
+
+	void JSON::readFromString(std::string s)
+	{
+		Tokenizer tokenizer;
+		tokenizer.appendInput(s);
+		std::vector<Token> stringTokens = tokenizer.tokenize();
+
+		readFromTokens(stringTokens, 0);
+	}
+
+	int JSON::readFromTokens(std::vector<Token> tokens, int pos)
+	{
+		this->tokens = tokens;
+		tokenPos = pos;
+		
+		consume(TokenType::LBrace);
+		while(nextTokenType() != TokenType::RBrace)
+		{
+			Token childName = consume(TokenType::StringLit);
+			// std::cout << "Child: " << childName.content << std::endl;
+			consume(TokenType::Colon);
+			switch(nextTokenType())
+			{
+			case TokenType::LBrace: tokenPos = children[childName.content].readFromTokens(tokens, tokenPos); break;
+			case TokenType::StringLit: children[childName.content].set<std::string>(consume(TokenType::StringLit).content); break;
+			case TokenType::IntLit: children[childName.content].set<int>(std::stoi(consume(TokenType::IntLit).content)); break;
+			case TokenType::FloatLit: children[childName.content].set<float>(std::stof(consume(TokenType::FloatLit).content)); break;
+			default: throw std::runtime_error("Token type is not a literal!");
+			}
+			if(nextTokenType() != TokenType::RBrace)
+				consume(TokenType::Comma);
+		}
+		consume(TokenType::RBrace);
+
+		return tokenPos;
+	}
 }