From d2808397640c17444b88368daa531f49d78289eb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kha=C3=AFs=20COLIN?= <khais.colin@gmail.com>
Date: Tue, 25 Feb 2025 15:24:52 +0100
Subject: [PATCH] command list refactor: use a builder struct

---
 src/parser/command_list/command_list.c | 96 +++++++++++++++++---------
 src/parser/command_list/command_list.h | 22 +++++-
 2 files changed, 86 insertions(+), 32 deletions(-)

diff --git a/src/parser/command_list/command_list.c b/src/parser/command_list/command_list.c
index 15d73ce..10e492b 100644
--- a/src/parser/command_list/command_list.c
+++ b/src/parser/command_list/command_list.c
@@ -6,13 +6,12 @@
 /*   By: khais <marvin@42.fr>                       +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/02/24 17:49:46 by khais             #+#    #+#             */
-/*   Updated: 2025/02/25 15:25:14 by khais            ###   ########.fr       */
+/*   Updated: 2025/02/26 12:51:57 by khais            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
 #include "command_list.h"
 #include "libft.h"
-#include "unistd.h"
 #include <stdlib.h>
 
 /*
@@ -81,45 +80,80 @@ static t_cmdlist	*allocate_command_list(t_wordlist *words)
 	return (output);
 }
 
+/*
+** setup a cmdlist_builder by allocating needed memory, and performing other
+** initialization steps.
+*/
+static t_cmdlist_builder	*setup_cmdlist_builder(
+	t_cmdlist_builder *builder,
+	t_wordlist **words)
+{
+	ft_bzero(builder, sizeof(t_cmdlist_builder));
+	builder->cmdlist = allocate_command_list(*words);
+	if (builder->cmdlist == NULL)
+		return (NULL);
+	builder->current_wordlist = NULL;
+	builder->current_word = wordlist_pop(words);
+	builder->idx = 0;
+	return (builder);
+}
+
+/*
+** Advance the state to the next word
+*/
+static void	cmdlist_builder_next_word(
+	t_cmdlist_builder *builder,
+	t_wordlist **words)
+{
+	builder->current_wordlist
+		= wordlist_push(builder->current_wordlist, builder->current_word);
+	builder->current_word = wordlist_pop(words);
+}
+
+/*
+** return true if we are currently adding the last pipeline in the chain
+*/
+static bool	cmdlist_builder_at_last_pipeline(t_cmdlist_builder *builder)
+{
+	return (builder->idx == builder->cmdlist->num_pipelines - 1);
+}
+
+static void	cmdlist_builder_delimit(
+	t_cmdlist_builder *builder,
+	t_wordlist **words)
+{
+	builder->cmdlist->pipelines[builder->idx]
+		= pipeline_from_wordlist(builder->current_wordlist);
+	if (cmdlist_builder_at_last_pipeline(builder))
+		builder->cmdlist->operators[builder->idx] = OP_END;
+	else
+		builder->cmdlist->operators[builder->idx]
+			= match_op(builder->current_word->word);
+	builder->current_wordlist = NULL;
+	worddesc_destroy(builder->current_word);
+	builder->current_word = wordlist_pop(words);
+	builder->idx++;
+}
+
 /*
 ** Create a new command list from the given wordlist.
 */
 t_cmdlist	*cmdlist_from_wordlist(t_wordlist *words)
 {
-	t_cmdlist	*output;
-	t_wordlist	*current_wordlist;
-	t_worddesc	*current_word;
-	int			idx;
+	t_cmdlist_builder	builder;
 
-	output = allocate_command_list(words);
-	if (output == NULL)
+	if (setup_cmdlist_builder(&builder, &words) == NULL)
 		return (NULL);
-	current_wordlist = NULL;
-	current_word = wordlist_pop(&words);
-	idx = 0;
-	while (current_word != NULL)
+	while (builder.current_word != NULL)
 	{
-		if (match_op(current_word->word) == OP_INVALID)
-		{
-			current_wordlist = wordlist_push(current_wordlist, current_word);
-			current_word = wordlist_pop(&words);
-		}
+		if (match_op(builder.current_word->word) == OP_INVALID)
+			cmdlist_builder_next_word(&builder, &words);
 		else
-		{
-			output->pipelines[idx] = pipeline_from_wordlist(current_wordlist);
-			output->operators[idx] = match_op(current_word->word);
-			current_wordlist = NULL;
-			worddesc_destroy(current_word);
-			current_word = wordlist_pop(&words);
-			idx++;
-		}
+			cmdlist_builder_delimit(&builder, &words);
 	}
-	if (current_wordlist != NULL)
-	{
-		output->pipelines[idx] = pipeline_from_wordlist(current_wordlist);
-		output->operators[idx] = OP_END;
-	}
-	return (output);
+	if (builder.current_wordlist != NULL)
+		cmdlist_builder_delimit(&builder, &words);
+	return (builder.cmdlist);
 }
 
 /*
diff --git a/src/parser/command_list/command_list.h b/src/parser/command_list/command_list.h
index 99166cb..55e9975 100644
--- a/src/parser/command_list/command_list.h
+++ b/src/parser/command_list/command_list.h
@@ -6,7 +6,7 @@
 /*   By: khais <marvin@42.fr>                       +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/02/24 17:45:01 by khais             #+#    #+#             */
-/*   Updated: 2025/02/25 15:25:14 by khais            ###   ########.fr       */
+/*   Updated: 2025/02/26 12:50:41 by khais            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -102,6 +102,26 @@ typedef struct s_cmdlist
 	t_operator	*operators;
 }	t_cmdlist;
 
+typedef struct s_cmdlist_builder
+{
+	/*
+	** list of cmds that we are building
+	*/
+	t_cmdlist	*cmdlist;
+	/*
+	** wordlist for the next pipeline
+	*/
+	t_wordlist	*current_wordlist;
+	/*
+	** word we are currently examining
+	*/
+	t_worddesc	*current_word;
+	/*
+	** index of the pipeline that is about to be inserted into the cmdlist
+	*/
+	int			idx;
+}	t_cmdlist_builder;
+
 t_cmdlist	*cmdlist_from_wordlist(t_wordlist *words);
 void		cmdlist_destroy(t_cmdlist *cmd);