parser: Add the bool type

This commit introduces a new type for booleans. There is no code
generation for this type yet. The intention of this commit is to enable
flow control in the near future.

Signed-off-by: Carlos Maniero <carlos@maniero.me>
Reviewed-by: Johnny Richard <johnny@johnnyrichard.com>

6 files changed, 60 insertions, 2 deletions

diff --git a/src/ast.c b/src/ast.c
index 5938e1d..8a46034 100644
--- a/src/ast.c
+++ b/src/ast.c
@@ -118,6 +118,24 @@ ast_node_new_literal_integer(uint32_t number)
 }
 
 ast_node_t *
+ast_node_new_literal_bool(bool boolean)
+{
+  ast_node_t *node = ast_node_new();
+
+  *node = (ast_node_t){
+    .kind = AST_LITERAL,
+    .data = {
+      .literal = {
+        .kind = AST_LITERAL_BOOL,
+        .value = { .boolean = boolean }
+      },
+    },
+  };
+
+  return node;
+}
+
+ast_node_t *
 ast_node_new_binary_operation(ast_binary_operation_kind_t kind, ast_node_t *left, ast_node_t *right)
 {
   ast_node_t *node = ast_node_new();
diff --git a/src/ast.h b/src/ast.h
index 69fc918..80148dc 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -22,7 +22,8 @@
 
 typedef enum
 {
-  TYPE_I32
+  TYPE_I32,
+  TYPE_BOOL
 } type_t;
 
 typedef struct ast_node_t ast_node_t;
@@ -67,12 +68,14 @@ typedef struct ast_binary_operation_t
 
 typedef enum
 {
-  AST_LITERAL_INTEGER
+  AST_LITERAL_INTEGER,
+  AST_LITERAL_BOOL
 } ast_literal_kind_t;
 
 typedef union
 {
   uint32_t integer;
+  bool boolean;
 } ast_literal_value_t;
 
 typedef struct ast_literal_t
@@ -148,6 +151,9 @@ ast_node_t *
 ast_node_new_literal_integer(uint32_t number);
 
 ast_node_t *
+ast_node_new_literal_bool(bool boolean);
+
+ast_node_t *
 ast_node_new_variable(ast_identifier_t *identifier);
 
 ast_node_t *
diff --git a/src/ast_pretty_printer.c b/src/ast_pretty_printer.c
index ec8d2de..95f5993 100644
--- a/src/ast_pretty_printer.c
+++ b/src/ast_pretty_printer.c
@@ -117,6 +117,11 @@ ast_pretty_printer_print_ast(ast_pretty_printer_t *printer, ast_node_t *ast)
           ast_pretty_printer_printf(printer, "Literal type=i32 value='%d'\n", literal.value.integer);
           break;
         }
+        case AST_LITERAL_BOOL:
+          ast_pretty_printer_set_lst_children(printer);
+          ast_pretty_printer_printf(
+            printer, "Literal type=bool value='%s'\n", literal.value.boolean ? "true" : "false");
+          break;
       }
       break;
     }
diff --git a/src/lexer.c b/src/lexer.c
index 72c27cd..f84163d 100644
--- a/src/lexer.c
+++ b/src/lexer.c
@@ -111,6 +111,14 @@ lexer_token_process_keyword(token_t *token)
     token->kind = TOKEN_KEYWORD_FN;
     return;
   }
+  if (string_view_eq(string_view_from_str("true"), token->value)) {
+    token->kind = TOKEN_TRUE;
+    return;
+  }
+  if (string_view_eq(string_view_from_str("false"), token->value)) {
+    token->kind = TOKEN_FALSE;
+    return;
+  }
 }
 
 void
@@ -454,6 +462,10 @@ token_kind_to_str(token_kind_t kind)
       return "fn";
     case TOKEN_KEYWORD_LET:
       return "let";
+    case TOKEN_TRUE:
+      return "true";
+    case TOKEN_FALSE:
+      return "false";
     case TOKEN_EOF:
       return "TOKEN_EOF";
     case TOKEN_UNKNOWN:
diff --git a/src/lexer.h b/src/lexer.h
index dd442cc..899c0aa 100644
--- a/src/lexer.h
+++ b/src/lexer.h
@@ -59,6 +59,8 @@ typedef enum
   TOKEN_KEYWORD_RETURN,
   TOKEN_KEYWORD_FN,
   TOKEN_KEYWORD_LET,
+  TOKEN_TRUE,
+  TOKEN_FALSE,
 
   TOKEN_UNKNOWN
 } token_kind_t;
diff --git a/src/parser.c b/src/parser.c
index baa2ef5..22313a6 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -84,6 +84,11 @@ parser_parse_type(parser_t *parser, type_t *type)
     return true;
   }
 
+  if (string_view_eq(token.value, string_view_from_str("bool"))) {
+    *type = TYPE_BOOL;
+    return true;
+  }
+
   parser_error_t error;
   error.token = token;
 
@@ -102,6 +107,12 @@ parser_literal_integer_node(token_t *token)
   return ast_node_new_literal_integer(atoi(number_as_str));
 }
 
+static ast_node_t *
+parser_literal_bool_node(token_t *token)
+{
+  return ast_node_new_literal_bool(token->kind == TOKEN_TRUE);
+}
+
 static ast_binary_operation_kind_t
 token_to_binary_operation_kind(token_t *token)
 {
@@ -128,6 +139,10 @@ parser_parse_factor(parser_t *parser)
   switch (token.kind) {
     case TOKEN_NUMBER:
       return parser_literal_integer_node(&token);
+    case TOKEN_TRUE:
+      return parser_literal_bool_node(&token);
+    case TOKEN_FALSE:
+      return parser_literal_bool_node(&token);
     case TOKEN_OPAREN: {
       ast_node_t *expression = parser_parse_expression(parser);