diff --git a/src/parser.cpp b/src/parser.cpp
new file mode 100644
index 0000000..57238f6
--- /dev/null
+++ b/src/parser.cpp
@@ -0,0 +1,326 @@
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+#include "include/colors.h"
+#include "include/parser.h"
+
+
+Node parse(vector<Token> tokens) {
+    reverse(tokens.begin(), tokens.end());
+
+    if (tokens.size() == 0)
+        throw new ParseException;
+        
+
+    // At least 1 instruction
+    ParseReturn ret = parse_instruction(tokens);
+    tokens = ret.tokens;
+
+    Node node = ret.node;
+
+    while (tokens.size() != 0) {
+        ParseReturn ret = parse_instruction(tokens);
+        tokens = ret.tokens;
+        
+        InnerNode new_node = {
+            .type=NodeType::Prog,
+            .children={node, ret.node}
+        };
+        node = new_node;
+    }
+
+    return node;
+}
+
+ParseReturn parse_instruction(vector<Token> tokens) {
+    try { //* Instruction -> Statement
+        ParseReturn ret = parse_statement(tokens);
+
+        return ret;
+    }
+    catch (const ParseException& pex) {
+        try { //* Instruction -> ExprStatement;
+            ParseReturn ret = parse_expr_statement(tokens);
+
+            tokens = ret.tokens;
+
+            if (tokens.back().type != TokenType::Semicolon)
+                throw new ParseException;
+
+            return {
+                .node=ret.node,
+                .tokens=tokens
+            };
+        }
+        catch (const ParseException& pex) {
+            try { //* Instruction -> Expr;
+                ParseReturn ret = parse_expr(tokens);
+                tokens = ret.tokens;
+
+                if (tokens.size() < 1 || tokens.back().type != TokenType::Semicolon)
+                    throw new ParseException;
+
+                return {
+                    .node=ret.node,
+                    .tokens=tokens
+                };
+            }
+            catch (const ParseException& pex) { //* Instruction -> ;
+                if (tokens.size() < 1 || tokens.back().type != TokenType::Semicolon)
+                    throw new ParseException;
+
+                vector<Node> children;
+                InnerNode epsilon_node = {
+                    .type=NodeType::Epsilon,
+                    .children=children
+                };
+                tokens.pop_back(); // On enlève le ';' de la liste de tokens
+
+                return {
+                    .node=epsilon_node,
+                    .tokens=tokens
+                };
+            }
+        }
+    }
+}
+
+ParseReturn parse_statement(vector<Token> tokens) {
+    (void)tokens;
+    // Aucune règle
+    throw new ParseException;
+}
+
+ParseReturn parse_expr_statement(vector<Token> tokens) {
+    if (tokens.size() < 1 || tokens.back().type != TokenType::Type)
+        throw new ParseException;
+
+    Token type = tokens.back();
+    tokens.pop_back();
+
+    if (tokens.size() < 1 || tokens.back().type != TokenType::Identifier)
+        throw new ParseException;
+
+    Token identifier = tokens.back();
+    tokens.pop_back();
+
+    //* ExprStatement -> Type Identifier
+    if (tokens.size() < 1 || tokens.back().type != TokenType::Equal) {
+        InnerNode node = {
+            .type=NodeType::Declaration,
+            .children={type, identifier}
+        };
+        return {
+            .node=node,
+            .tokens=tokens
+        };
+    }
+
+    //* ExprStatement -> Type Identifier = Expr
+    // On retire le '='
+    tokens.pop_back();
+
+    ParseReturn ret = parse_expr(tokens);
+
+    InnerNode node = {
+        .type=NodeType::Declaration,
+        .children={type, identifier, ret.node}
+    };
+    return {
+        .node=node,
+        .tokens=ret.tokens
+    };
+}
+
+ParseReturn parse_expr(vector<Token> tokens) {
+    if (tokens.size() == 0)
+        throw new ParseException;
+
+    // At least 1 T
+    ParseReturn ret = parse_t(tokens);
+    tokens = ret.tokens;
+
+    Node node = ret.node;
+
+    //* We construct a tree
+    while (tokens.size() != 0) {
+        try {
+            ParseReturn ret = parse_t(tokens);
+            tokens = ret.tokens;
+        } catch (const ParseException& pex) {
+            return {
+                .node=node,
+                .tokens=tokens
+            };
+        }
+        
+        if (tokens.size() != 0) {
+            if (tokens.back().type == TokenType::Plus) {
+                InnerNode new_node = {
+                    .type=NodeType::Plus,
+                    .children={node, ret.node}
+                };
+                node = new_node;
+            } else if (tokens.back().type == TokenType::Minus) {
+                InnerNode new_node = {
+                    .type=NodeType::Minus,
+                    .children={node, ret.node}
+                };
+                node = new_node;
+            }
+        }
+    }
+
+    return {
+        .node=node,
+        .tokens=tokens
+    };
+}
+
+ParseReturn parse_t(vector<Token> tokens) {
+    if (tokens.size() == 0)
+        throw new ParseException;
+        
+
+    // At least 1 U
+    ParseReturn ret = parse_u(tokens);
+    tokens = ret.tokens;
+
+    Node node = ret.node;
+
+    //* We construct a tree
+    while (tokens.size() != 0) {
+        try {
+            ParseReturn ret = parse_u(tokens);
+            tokens = ret.tokens;
+        } catch (const ParseException& pex) {
+            return {
+                .node=node,
+                .tokens=tokens
+            };
+        }
+        
+        if (tokens.size() != 0) {
+            if (tokens.back().type == TokenType::Star) {
+                InnerNode new_node = {
+                    .type=NodeType::Mult,
+                    .children={node, ret.node}
+                };
+                node = new_node;
+            } else if (tokens.back().type == TokenType::Slash) {
+                InnerNode new_node = {
+                    .type=NodeType::Div,
+                    .children={node, ret.node}
+                };
+                node = new_node;
+            } else if (tokens.back().type == TokenType::Percent) {
+                InnerNode new_node = {
+                    .type=NodeType::Mod,
+                    .children={node, ret.node}
+                };
+                node = new_node;
+            }
+        }
+    }
+
+    return {
+        .node=node,
+        .tokens=tokens
+    };
+}
+
+ParseReturn parse_u(vector<Token> tokens) {
+    if (tokens.size() > 0 && tokens.back().type == TokenType::Minus) { //* U -> - U
+        tokens.pop_back();
+
+        ParseReturn ret = parse_u(tokens);
+
+        InnerNode node = {
+            .type=NodeType::UnaryMinus,
+            .children={ ret.node }
+        };
+        return {
+            .node=node,
+            .tokens=ret.tokens
+        };
+    }
+    
+    if (tokens.size() > 0 && tokens.back().type == TokenType::Plus) { //* U -> + U
+        tokens.pop_back();
+
+        ParseReturn ret = parse_u(tokens);
+
+        InnerNode node = {
+            .type=NodeType::UnaryPlus,
+            .children={ ret.node }
+        };
+        return {
+            .node=node,
+            .tokens=ret.tokens
+        };
+    }
+
+    //* U -> F
+    return parse_f(tokens);
+}
+
+ParseReturn parse_f(vector<Token> tokens) {
+    if (tokens.size() == 0)
+        throw new ParseException;
+
+    switch (tokens.back().type) {
+        case TokenType::Number: { //* U -> Number
+            Token number = tokens.back();
+            tokens.pop_back();
+            return {
+                .node=number,
+                .tokens=tokens
+            };;
+        }
+        case TokenType::LParenthese: { //* U -> Identifier
+            tokens.pop_back();
+            ParseReturn ret = parse_expr(tokens);
+            tokens=ret.tokens;
+
+            if (tokens.size() < 1 || tokens.back().type != TokenType::RParenthese)
+                throw new ParseException;
+
+            tokens.pop_back();
+            InnerNode node = {
+                .type=NodeType::Parenthesis,
+                .children={ ret.node }
+            };
+            return {
+                .node=node,
+                .tokens=tokens
+            };
+        }
+        case TokenType::Identifier: { //* U -> Identifier...
+            Token identifier = tokens.back();
+            tokens.pop_back();
+
+            if (tokens.size() > 0 && tokens.back().type == TokenType::Equal) { //* U -> Identifier = Expr
+                tokens.pop_back();
+                ParseReturn ret = parse_expr(tokens);
+
+                InnerNode node = {
+                    .type = NodeType::Assignment,
+                    .children = { identifier, ret.node }
+                };
+                return {
+                    .node=node,
+                    .tokens=ret.tokens
+                };
+            }
+
+            return { //* U -> Identifier
+                .node=identifier,
+                .tokens=tokens
+            };
+        }
+        default:
+            throw new ParseException;
+    }
+}
\ No newline at end of file