|\ merge from release-0.3, released as 0.3.

ChangeLog.rst

@@ -1,3 +1,9 @@
+ayrton (0.3) unstable; urgency=low
+
+  * Piping and basic redirection works.
+
+ -- Marcos Dione <[email protected]>  Thu, 03 Oct 2013 20:42:12 +0200
+
 ayrton (0.2) unstable; urgency=low
 
   * New function `options()` is similar to `bash`'s `set` command. So far

README.md

@@ -48,7 +48,7 @@ So, in short:
     To generate the docs:
     # make docs
 
-# First steps
+# First steps: execution, output
 
 `ayrton` syntax is Python3's with some things changed. Here's the unavoidable
 'Hello world' example:
@@ -83,22 +83,41 @@ While we're discussing output, check out this:
 
 Just guess were the output went :) ... (ok, ok, it went to `/dev/null`).
 
+# Composing
+
 Just like `sh`, you can nest callables, but you must explicitly tell it that you
 want to capture the output so the nesting callable gets its input:
 
-    root= grep (cat ('/etc/shadow', _out=Capture), 'root', _out=Capture)
+    root= grep (cat ('/etc/passwd', _out=Capture), 'root', _out=Capture)
 
 This seems more cumbersome than `sh`, but if you think that in any shell language
 you do something similar (either using `$()`, `|` or even redirection), it's not
 a high price to pay.
 
 Another improvement over `sh` is that you can use commands as conditions:
 
-    if grep (cat ('/etc/shadow', _out=Capture), 'mdione', _out=None):
+    if grep (cat ('/etc/passwd', _out=Capture), 'mdione', _out=None):
         print ('user «mdione» is present on your system; that's a security vulnerability right there!')
 
 As a consequence, you can also use `and`, `or` and `not`.
 
+# Piping, redirection
+
+Of course, no shell scripting language can call itself so without piping, so
+we had to implement it:
+
+    if cat ('/etc/passwd') | grep ('mdione', _out=None):
+        print ('I'm here, baby!')
+
+Notice that this time you don't have to be explicit about the `cat`'s output;
+we know it's going to a pipe, so we automatically `Capture` it. Of course, we
+also have redirection:
+
+    grep ('mdione') < '/etc/passwd' > '/tmp/foo'
+    grep ('root') < '/etc/passwd' >> '/tmp/foo'
+
+# Shell compatibility
+
 Do I have you attention? Let's go for your interest. Something also useful is a
 behavior similar to `pushd`/`popd`:
 
@@ -144,6 +163,8 @@ can hold any Python object, but won't be exported. The `export()` function
 gives the same behavior as `bash`'s `export` command, with the caveat that values
 will be automatically converted to `str`.
 
+# Remote execution
+
 The cherry on top of the cake, or more like the melon of top of the cupcake, is
 (semi) transparent remote execution. This is achieved with the following construct:
 

TODO.rst

@@ -4,8 +4,6 @@ attack it offline (when I code best).
 Really do:
 ----------
 
-* source
-* shift
 * better error reporting, including remotes
 * better sh() interface (streams? yuk!)
 * we're weeding out imports, we could gather a list and reimport them in the
@@ -15,12 +13,6 @@ Really do:
 
 * if we can implement |, then no function nesting
 
-   * | is implementable, implement __ror__() for RunningCommandWrapper
-
-      * it doesn't work, __ror__() is not called and in any case it's
-        already too late, cat and grep have benn already called when
-        __or__ is called (with two RunningCommandWrapper instances)
-
       * becareful with if cat () | grep (); error codes must be carried too
 
 * process substitution
@@ -31,13 +23,12 @@ Really do:
 
    * see pdb's source
 
-* referencing non-existant envvars (FOO) is replaced by a Runner.
 * becareful with buitins, might eclipse valid usages: bash() (exp) blocks /bin/bash
 
    * add option _exec=Ture for actually executing the binary.
 
 * check ``bash``'s manpage and see what's missing.
-* subprocess + redirection (...) > foo.txt
+* subprocess
 
    * with ayrton (): ...
 
@@ -48,7 +39,4 @@ If we {have time,are bored}:
 ----------------------------
 
 * what to do about relative/absolute command paths?
-* better error reporting
-* | (pipe)
-* redirections, if we ever implement |
 * executable path caching à la bash.