From 13d1168401e1f4a5440f7de43b71d72df7c008f3 Mon Sep 17 00:00:00 2001
From: Sage Vaillancourt <sagev9000@tutanota.com>
Date: Fri, 8 Apr 2022 10:23:12 -0400
Subject: [PATCH] Wire up basic readline history/completion.

---
 src/examples/pebblisp.pbl | 14 +++++++++--
 src/main.c                | 51 +++++++++++++++++++++++++++++++++------
 2 files changed, 55 insertions(+), 10 deletions(-)

diff --git a/src/examples/pebblisp.pbl b/src/examples/pebblisp.pbl
index 0f33e3d..9f83b03 100644
--- a/src/examples/pebblisp.pbl
+++ b/src/examples/pebblisp.pbl
@@ -14,7 +14,11 @@
 
 (def nl (ch 10))
 
-(def fore (fn (f list) ((map f list) "")))
+(def fore (fn (action list)
+  "Apply the given action to each element in list." (
+  (map f list)
+  ""
+)))
 
 (def first (fn (list) (at 0 list)))
 
@@ -23,6 +27,11 @@
 
 (def config (cat ~ "/.pebblisp.pbl"))
 
+(def loadfile (fn (file-name)
+  "Read and evaluate the file with the given name." (
+  (eval (rf file-name))
+)))
+
 (def reloadConfig (fn () (loadfile config)))
 
 (def string (fn (a) (cat "" a)))
@@ -65,7 +74,8 @@
 
 (def clock (fn (ti) (cat (hour ti) ":" (zero ti.minute) ":" (zero ti.sec))))
 
-(def cleanDir (fn () (
+(def cleanDir (fn ()
+  "Get a string of the current directory" (
   (def di (cwd))
   (if (matches di (cat ~ "*"))
     (cat "~" (substr (slen ~) 999 di))
diff --git a/src/main.c b/src/main.c
index a04ca3f..4df645a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -8,6 +8,15 @@
 #include <readline/history.h>
 #include <unistd.h>
 
+struct Settings {
+    int runTests;
+    int ignoreConfig;
+    int ignoreLib;
+    int moreToDo;
+    const char* configFile;
+    char historyFile[128];
+} settings;
+
 Object getPrompt(struct Environment* env)
 {
     Object prompt = fetchFromEnvironment("prompt", env);
@@ -47,11 +56,39 @@ void sigintHandler(unused int signalNumber)
     cleanObject(&p);
 }
 
+char* completionGenerator(const char* text, int state)
+{
+    static size_t i;
+    static size_t completionLength;
+    if (state == 0) {
+        i = 0;
+        completionLength = strlen(text);
+    }
+
+    struct ObjectTable* table = &global()->table;
+    for (; i < table->capacity; i++) {
+        if (table->elements[i].symbol && strncmp(table->elements[i].symbol, text, completionLength) == 0) {
+            char* symbol = malloc(sizeof(char) * (strlen(table->elements[i].symbol) + 1));
+            strcpy(symbol, table->elements[i].symbol);
+            i++;
+            return symbol;
+        }
+    }
+    return NULL;
+}
+
+char** completer(const char* text, int start, int end)
+{
+    return rl_completion_matches(text, completionGenerator);
+}
+
 void repl(struct Environment* env)
 {
+    rl_attempted_completion_function = completer;
     signal(SIGINT, sigintHandler);
     char* buf;
     using_history();
+    read_history(settings.historyFile);
 
     while ((buf = prompt(env)) != NULL) {
         if (strcmp("q", buf) == 0) {
@@ -81,6 +118,7 @@ void repl(struct Environment* env)
             cleanObject(&o);
             system(buf);
             free(buf);
+            write_history(settings.historyFile);
             continue;
         }
         free(buf);
@@ -91,6 +129,7 @@ void repl(struct Environment* env)
         printColored(output);
         free(output);
         printf("\n");
+        write_history(settings.historyFile);
     }
 }
 
@@ -144,14 +183,6 @@ void setupSegfaultHandler()
 }
 #endif
 
-struct Settings {
-    int runTests;
-    int ignoreConfig;
-    int ignoreLib;
-    int moreToDo;
-    const char* configFile;
-} settings;
-
 #define RUN_TESTS_ARG "--run-tests"
 #define RUN_DETAILED_TESTS "=detailed"
 #define IGNORE_CONFIG_ARG "--ignore-config"
@@ -160,12 +191,16 @@ struct Settings {
 
 void getSettings(int argc, const char* argv[])
 {
+    const char* const home = getenv("HOME");
+
     settings.runTests = 0;
     settings.ignoreConfig = 0;
     settings.ignoreLib = 0;
     settings.moreToDo = 0;
     settings.configFile = NULL;
 
+    sprintf(settings.historyFile, "%s/.plhist", home);
+
     size_t runTestsLen = strlen(RUN_TESTS_ARG);
     size_t configFileLen = strlen(CONFIG_FILE_ARG);
     for (int i = 1; i < argc; i++) {