From 143f91aef3937e135905985d21f31483bb16a3a2 Mon Sep 17 00:00:00 2001
From: Laurent Mazet <mazet@softndesign.org>
Date: Sun, 29 Jan 2023 00:26:12 +0100
Subject: [PATCH] clear feature

---
 calc.c   |  2 ++
 parser.c | 14 +++++++++++++-
 parser.h |  2 +-
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/calc.c b/calc.c
index 6950ad5..f79a89a 100644
--- a/calc.c
+++ b/calc.c
@@ -373,6 +373,8 @@ int main (int argc, char *argv[])
 // test: echo -e 'rcl (3)\ndisp' | calc.exe | grep -q "storage: 0 0 0 0 0 0 0 0 0 0"
 // test: echo -e 'inc (2)\ndisp' | calc.exe | grep -q "storage: 0 1 0 0 0 0 0 0 0 0"
 // test: echo -e 'dec (2)\ndisp' | calc.exe | grep -q "storage: 0 -1 0 0 0 0 0 0 0 0"
+// test: echo -e 'sto (3, pi)\nclr\ndisp' | calc.exe | grep -q "storage: 0 0 0 0 0 0 0 0 0 0"
+// test: echo -e 'mem (3)\nclr' | calc.exe -v 3 | grep -q Clear
 
 // Gauss sequence
 // test: echo -e '{sto (1, 0), sto (10, 0), while (inc (10) < 100, {sto (1, rcl (1) + rcl (10)), print (rcl (1))})};' | calc.exe | grep -q '=> 5050'
diff --git a/parser.c b/parser.c
index a1602a0..38b7c26 100644
--- a/parser.c
+++ b/parser.c
@@ -122,7 +122,7 @@ keyword_t operators[NB_OPERATORS] = {
     { "|",   Or, 2, 1, -2}
 };
 
-#define NB_FUNCTIONS 25
+#define NB_FUNCTIONS 26
 keyword_t functions[NB_FUNCTIONS] = {
     { "sqrt", Sqr, 1, 4, 5},
     { "pow",  Pow, 2, 3, 5},
@@ -143,6 +143,7 @@ keyword_t functions[NB_FUNCTIONS] = {
     { "dec",  Dec, 1, 3, 5},
     { "disp", Disp, 0, 4, 9},
     { "mem",  Mem, 1, 3, 9},
+    { "clr",  Clear, 0, 3, 9},
     { "quit", Quit, 0, 4, 9},
     { "help", Help, 0, 4, 9},
     { "!",    Not, 1, 1, 6},
@@ -507,6 +508,7 @@ void print_element (element_t *root, int level)
     case Dec: func = "Decrease"; break;
     case Disp: func = "Display"; break;
     case Mem: func = "Memory"; break;
+    case Clear: func = "Clear"; break;
     case Quit: func = "Quit"; break;
     case Help: func = "Help"; break;
     case Ans: func = "Ans"; break;
@@ -631,6 +633,14 @@ void display (void)
     fprintf (stdout, "\n");
 }
 
+void clear ()
+{
+    int i;
+    for (i = 0; i < storage_size; i++) {
+        storage[i] = 0;
+    }
+}
+
 /* While do function */
 
 double while_do (element_t *cond, element_t *action)
@@ -824,6 +834,7 @@ double evaluate_element (element_t *root, char mask)
         }
         break;
     case Disp:
+    case Clear:
     case Quit:
     case Help:
     case Ans:
@@ -869,6 +880,7 @@ double evaluate_element (element_t *root, char mask)
     case Dec: return decrease ((int)op0);
     case Disp: display (); break;
     case Mem: memory ((int)op0); break;
+    case Clear: clear (); break;
     case Quit: quit (); break;
     case Help: help (); break;
     case Ans: return answer;
diff --git a/parser.h b/parser.h
index f521129..2e3e6d4 100644
--- a/parser.h
+++ b/parser.h
@@ -15,7 +15,7 @@ typedef enum {
     Cos, Sin, Tan, Acos, Asin, Atan,
     Log, Exp,
     Abs, Ceil, Floor,
-    Store, Recall, Inc, Dec, Disp, Mem,
+    Store, Recall, Inc, Dec, Disp, Mem, Clear,
     Quit, Help,
     Ans, E, Pi,
     Equal, Diff, Ge, Le, Gt, Lt,
-- 
2.30.2