From 1a56830da1b5753f31d9a4b2b96cfc6a45d7d2d8 Mon Sep 17 00:00:00 2001
From: Aaron Taylor <ataylor@subgeniuskitty.com>
Date: Fri, 12 Jul 2019 22:08:51 -0700
Subject: [PATCH] Added VVS stdlib function to dump heap in human readable
 form.

---
 stdlib/README.md  |  5 +++--
 stdlib/debug.pvvs | 53 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 2 deletions(-)
 create mode 100644 stdlib/debug.pvvs

diff --git a/stdlib/README.md b/stdlib/README.md
index ee4670b..2bba7d5 100644
--- a/stdlib/README.md
+++ b/stdlib/README.md
@@ -36,8 +36,9 @@ header comment for each function to learn the call and return stack.
          011xxx - unassigned
          100xxx - unassigned
          101xxx - unassigned
-         110xxx - unassigned
-         111xxx - conversion functions
+         110xxx - conversion functions
+         111xxx - debug functions
+         111000 ----- dump heap                     (debug.pvvs)
         1xxxxxx - reserved for less common entry points
         1000000 ----- print sign of number          (stdio.pvvs)
         1000001 ----- print magnitude of number     (stdio.pvvs)
diff --git a/stdlib/debug.pvvs b/stdlib/debug.pvvs
new file mode 100644
index 0000000..db61a96
--- /dev/null
+++ b/stdlib/debug.pvvs
@@ -0,0 +1,53 @@
+#ifndef VVS_STDLIB_DEBUG
+#define VVS_STDLIB_DEBUG
+
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+@ Description:
+@   This function dumps the heap from startaddr to endaddr.
+@ Call Stack:
+@   endaddr
+@   startaddr  <-- TOS
+@ Return Stack:
+@   <empty>
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+NSSVTTTSSSN              | Mark: 111000 (dump heap)
+
+@ Prepare a numeric address and value on the stack
+SNS                      | DUP
+SNS                      | DUP
+TTT                      | LOAD
+SNT                      | SWAP
+
+@ Print output line for this memory location
+NSTTSSSSSTN              | JSR>1000001 (print absolute value of number)
+SSSTTTSTSN               | PUSH ASCII ':'
+SSSTSSTN                 | PUSH ASCII '\t'
+TNSS                     | PUTC
+TNSS                     | PUTC
+NSTTSTSN                 | JSR>1010 (print number from stack)
+SSSTSTSN                 | PUSH ASCII '\n'
+TNSS                     | PUTC
+
+@ Figure out if the loop is complete.
+SSSSN                    | PUSH 0 (ptr)
+SNT                      | SWAP
+TTS                      | STORE
+SNS                      | DUP
+SSSSN                    | PUSH 0 (ptr)
+TTT                      | LOAD
+TSST                     | SUBTRACT
+NTSSSTTTSSSSSSSSSSSN     | BRZ > 00111000 00000000
+SSSSN                    | PUSH 0 (ptr)
+TTT                      | LOAD
+SSSTN                    | PUSH 1
+TSSS                     | ADD
+NSNTTTSSSN               | JMP>111000 (dump heap)
+
+@ Clean up and return
+NSSVSSTTTSSSSSSSSSSSN    | Mark: 00111000 00000000
+SNN                      | DROP
+NTN                      | RTS
+
+#include <stdio.pvvs>
+
+#endif
-- 
2.20.1