feat: begin parsing

src/01_lexic/root.zig

@@ -10,8 +10,8 @@ const string = @import("string.zig");
 const grouping = @import("grouping.zig");
 const punctuation = @import("punctiation.zig");
 
-const TokenType = token.TokenType;
-const Token = token.Token;
+pub const TokenType = token.TokenType;
+pub const Token = token.Token;
 
 /// Creates an array list of tokens. The caller is responsible of
 /// calling `deinit` to free the array list

src/02_syntax/root.zig

@@ -1,5 +1,56 @@
 const std = @import("std");
+const lexic = @import("lexic");
+const Token = lexic.Token;
+const TokenType = lexic.TokenType;
+
+const TokenStream = std.ArrayList(Token);
+
+const ParseError = error{
+    Unmatched,
+    Error,
+};
+
+const Statement = union(enum) {
+    VariableBinding: u8,
+};
+
+const VariableBinding = struct {
+    is_mutable: bool,
+    datatype: ?*Token,
+    identifier: *Token,
+    expression: Expression,
+
+    fn parse() !@This() {}
+};
+
+const Expression = union(enum) {
+    number: *const Token,
+
+    /// Attempts to parse an expression from a token stream.
+    fn parse(tokens: *const TokenStream, pos: usize) ParseError!@This() {
+        std.debug.assert(pos < tokens.items.len);
+
+        const t = tokens.items[pos];
+        if (t.token_type != TokenType.Int) {
+            return ParseError.Unmatched;
+        }
+
+        return .{
+            .number = &t,
+        };
+    }
+};
 
 test {
     std.testing.refAllDecls(@This());
 }
+
+test "should parse expression" {
+    const input = "322";
+    const tokens = try lexic.tokenize(input, std.testing.allocator);
+    defer tokens.deinit();
+
+    const expr = try Expression.parse(&tokens, 0);
+    try std.testing.expectEqualDeep("322", expr.number.value);
+    try std.testing.expectEqualDeep(TokenType.Int, expr.number.token_type);
+}