parser: Add support for variables and identifiers in function body

This commit adds support for variables and identifiers in the function
body of the parser, stored as a vector.

However, at this point, identifier resolution is not fully implemented,
and we currently accept identifiers without checking if they can be
resolved. This is a known limitation that will be addressed in a future
commit once hash-tables are added to the parser.

Signed-off-by: Carlos Maniero <carlosmaniero@gmail.com>
Reviewed-by: Johnny Richard <johnny@johnnyrichard.com>

1 files changed, 23 insertions, 6 deletions

diff --git a/src/ast.h b/src/ast.h
index 70852b1..5ba21ad 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -18,6 +18,7 @@
 #define AST_H
 #include <stdint.h>
 #include "string_view.h"
+#include "vector.h"
 
 #define ast_visitor_visit(visitor, node) ast_node_accept_visitor(node, (ast_visitor_t *) visitor);
 
@@ -35,7 +36,7 @@ typedef struct ast_return_stmt_t {
 typedef struct ast_function_declaration_t {
   string_view_t name;
   type_t  return_type;
-  ast_node_t* body;
+  vector_t* body;
 } ast_function_declaration_t;
 
 typedef struct ast_binary_operation_t {
@@ -58,6 +59,16 @@ typedef struct ast_literal_t {
   ast_literal_value_t value;
 } ast_literal_t;
 
+typedef struct ast_identifier_t {
+  string_view_t name;
+} ast_identifier_t;
+
+typedef struct ast_variable_declaration_t {
+  string_view_t name;
+  type_t type;
+  ast_node_t* value;
+} ast_variable_declaration_t;
+
 typedef struct ast_visitor_t {
   void (*visit_function)(struct ast_visitor_t *, ast_function_declaration_t *);
   void (*visit_return_stmt)(struct ast_visitor_t *, ast_return_stmt_t *);
@@ -66,18 +77,22 @@ typedef struct ast_visitor_t {
 } ast_visitor_t;
 
 typedef enum {
-  AST_FUNCTION_DECLARATION,
   AST_BINARY_OPERATION,
+  AST_FUNCTION_DECLARATION,
+  AST_IDENTIFIER,
   AST_LITERAL,
   AST_RETURN_STMT,
-  AST_UNKOWN_NODE
+  AST_UNKOWN_NODE,
+  AST_VARIABLE_DECLARATION,
 } ast_node_kind_t;
 
 typedef union {
-  ast_function_declaration_t function;
   ast_binary_operation_t binary_operation;
+  ast_function_declaration_t function;
   ast_literal_t literal;
   ast_return_stmt_t return_stmt;
+  ast_variable_declaration_t variable;
+  ast_identifier_t identifier;
 } ast_node_data_t;
 
 typedef struct ast_node_t {
@@ -91,9 +106,11 @@ void ast_node_accept_visitor(ast_node_t *node, ast_visitor_t *visitor);
 ast_node_t* ast_node_new();
 void ast_node_destroy(ast_node_t *node);
 
-void ast_node_init_function_declaration(ast_node_t *node, string_view_t name, type_t return_type, ast_node_t *body);
-void ast_node_init_return_stmt(ast_node_t *node, ast_node_t *argument);
 void ast_node_init_binary_operation(ast_node_t *node, string_view_t op, ast_node_t *left, ast_node_t *right);
+void ast_node_init_function_declaration(ast_node_t *node, string_view_t name, type_t return_type, vector_t *body);
+void ast_node_init_identifier(ast_node_t *node, string_view_t name);
+void ast_node_init_return_stmt(ast_node_t *node, ast_node_t *argument);
+void ast_node_init_variable_declaration(ast_node_t *node, string_view_t variable_name, type_t type, ast_node_t *value);
 // FIXME: use the naming convention
 void ast_literal_integer_create(ast_node_t* node, uint32_t number);