From 4cb04d03e9d6a8048d465dbfc9adb6c74bfda495 Mon Sep 17 00:00:00 2001
From: d6 <d_m@plastic-idolatry.com>
Date: Mon, 7 Feb 2022 23:00:15 -0500
Subject: [PATCH] add grep and femto

---
 femto    |  7 +++++++
 grep.tal | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100755 femto
 create mode 100644 grep.tal

diff --git a/femto b/femto
new file mode 100755
index 0000000..fb63adb
--- /dev/null
+++ b/femto
@@ -0,0 +1,7 @@
+#!/bin/sh
+
+TTY=`stty -g`
+uxnasm femto.tal femto.rom
+stty raw -echo
+uxncli femto.rom
+stty "$TTY"
diff --git a/grep.tal b/grep.tal
new file mode 100644
index 0000000..b98cc4c
--- /dev/null
+++ b/grep.tal
@@ -0,0 +1,47 @@
+( grep.tal )
+( )
+( by d_m )
+
+( print a character to STDOUT )
+%emit { #18 DEO }
+
+( the first argument to grep is the regex )
+( arguments are passed on STDIN, so we just )
+( assume the first "line" is the argument )
+( and the rest are lines to be grepped )
+|0100
+    ;r-read-stdin #10 DEO2 BRK
+
+@regex 0000   ( compiled regex address (if any) )
+@buffer $1000 ( buffer to read user input )
+@ptr :buffer  ( next byte to write in buffer )
+
+@println ( s* -> )
+    &loop LDAk #00 EQU ,&eof JCN ( did we reach \0 ? )
+    LDAk emit INC2 ,&loop JMP    ( no so emit a char and repeat )
+    &eof #0a emit POP2 JMP2r     ( yes so emit \n and return )
+
+@r-read-stdin ( -> )
+    #12 DEI #0a EQU ,&execute JCN     ( did we read \n ? )
+    #12 DEI ;ptr LDA2 STA             ( no, so save in buffer )
+    ;ptr LDA2k INC2 SWP2 STA2         ( ptr++ )
+    BRK                               ( return )
+
+    &execute                          ( we saw a newline, so do something )
+    #00 ;ptr LDA2 STA                 ( null terminate str )
+    ;buffer ;ptr STA2                 ( reset ptr )
+    ;regex LDA2 #0000 EQU2            ( is regex initialized? )
+    ,&need-regex JCN                  ( jump if unset )
+
+                                      ( regex is set )
+    ;buffer ;regex LDA2 ;match JSR2   ( match regex )
+    #00 EQU ,&no-match JCN            ( did we match? )
+    ;buffer ;println JSR2             ( print any match )
+    &no-match BRK                     ( return )
+
+                                      ( regex is unset )
+    &need-regex ;buffer ;compile JSR2 ( compile regex )
+    ;regex STA2 BRK                   ( save regex and return )
+
+( include the actual regex machinery )
+~regex.tal