parser: create a block node type

Since the next step to pipa programming language is about having control
flow statements we could benefit ourselves by having a block node to
control scope. Now, functions has a block node, instead of an vector as
body. As you can see through the ast-dump:

  FunctionDecl name='main'
  └─ body:
    └─ Block
      └─ ReturnStmt
        └─ Literal type=i32 value='69'

This same node kind can be used for parsing if, for and while blocks.

I could use ast_block_t as body for functions but instead, I opted to
use an ast_node_t. This brings the flexibility to, in the future, having
another function body kinds, such as arrow functions if we want to:

  fn add(a: i32, b: i32): i32 => a + b;

Signed-off-by: Carlos Maniero <carlos@maniero.me>

1 files changed, 12 insertions, 2 deletions

diff --git a/src/ast.h b/src/ast.h
index f95aee2..1637173 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -29,6 +29,11 @@ typedef enum
 
 typedef struct ast_node_t ast_node_t;
 
+typedef struct ast_block_t
+{
+  vector_t *body;
+} ast_block_t;
+
 typedef struct ast_return_stmt_t
 {
   ast_node_t *argument;
@@ -48,7 +53,7 @@ typedef struct ast_function_declaration_t
 {
   ast_identifier_t identifier;
   type_t return_type;
-  vector_t *body;
+  ast_node_t *body;
 } ast_function_declaration_t;
 
 typedef enum ast_binary_operation_kind_t
@@ -109,6 +114,7 @@ typedef struct ast_variable_assignment_t
 typedef enum
 {
   AST_BINARY_OPERATION,
+  AST_BLOCK,
   AST_FUNCTION_DECLARATION,
   AST_LITERAL,
   AST_RETURN_STMT,
@@ -123,6 +129,7 @@ typedef union
   ast_binary_operation_t binary_operation;
   ast_function_declaration_t function;
   ast_literal_t literal;
+  ast_block_t block;
   ast_return_stmt_t return_stmt;
   ast_variable_declaration_t variable_declaration;
   ast_variable_assignment_t variable_assignment;
@@ -155,7 +162,7 @@ ast_node_new_binary_operation(ast_binary_operation_kind_t kind,
                               type_t result_type);
 
 ast_node_t *
-ast_node_new_function_declaration(string_view_t function_name, type_t return_type, vector_t *body);
+ast_node_new_function_declaration(string_view_t function_name, type_t return_type, ast_node_t *body);
 
 ast_node_t *
 ast_node_new_return_stmt(ast_node_t *argument);
@@ -167,6 +174,9 @@ ast_node_t *
 ast_node_new_literal_integer(uint32_t number);
 
 ast_node_t *
+ast_node_new_block(vector_t *body);
+
+ast_node_t *
 ast_node_new_literal_bool(bool boolean);
 
 ast_node_t *