4 files changed, 61 insertions(+), 7 deletions(-)

M README.md
M conf/cog.yml
M conf/defaults.yml
M wkrel/util.py

@@ 161,7 161,7 @@ contain any alphanumeric character, dashes (`-`), and underscores (`_`). The
 dot (`.`) character can be used to access subelements of variables which
 behave like mappings. The following are valid examples:
 
-- `%{date}` expands to a generatd value corresponsing to the current date.
+- `%{date}` expands to a generated value corresponding to the current date.
 - `%{package}` expands to the value of the `package` configuration value.
 - `%{email.sender}` expands to the `sender` configuration item of the
   `email` configuration value (which is a mapping).


@@ 169,6 169,24 @@ behave like mappings. The following are valid examples:
 All configuration values are made available as variables, which means that
 both `%{name}` and `%{variables.name}` will expand to the same value.
 
+The result of variable expansion can itself be a template, but its expansion
+needs to be triggered explicitly by using an asterisk as prefix of the
+variable name: `%{*…}`. The main usage of nested template expansion is reusing
+variables as template fragments, as in the following example:
+
+```yaml:
+variables:
+  tar-checksums: |
+    md5 %{tar.md5sum} %{tar.filename}
+    sha1 %{tar.sha1sum} %{tar.filename}
+    sha256 %{tar.sha256sum} %{tar.filename}
+
+files:
+  sums: |
+    Checksums for %{package} %{version}:
+    %{*tar-checksums}
+```
+
 
 #### Variables
 

@@ 1,5 1,5 @@
 pattern: cog-%.tar.xz
-package: cog
+package: Cog
 
 variables:
   url: https://wpewebkit.org

@@ 1,5 1,5 @@
 variables:
-  -announcement-template: &-announcement-template |
+  email-template: &email-template |
     %{package} %{version} is available for download at:
 
     %{url}/releases/%{tar.filename} (%{tar.humansize})


@@ 49,8 49,8 @@ changelog: NEWS
 
 email:
   sender: "noreply@domain.tld"
-  subject: "%{package} %{version} available!"
-  template: *-announcement-template
+  subject: "%{package} %{version} released"
+  template: *email-template
 
 files:
   news: |


@@ 62,4 62,33 @@ files:
        md5sum: %{tar.md5sum}
        sha1sum: %{tar.sha1sum}
        sha256sum: %{tar.sha256sum}
-  md: *-announcement-template
+  eml: |
+    Subject: %{*email.subject}
+    From: %{email.sender}
+    To: %{email.recipients}
+
+    %{*email-template}
+  md: |
+    ---
+    layout: post
+    title: %{package} %{version} released
+    tags: [release]
+    package: %{package}  # FIXME
+    version: %{version}
+    permalink: /release/%{package}-%{version}.html
+    ---
+
+    %{release-tagline}
+
+    ### What's new in %{package} %{version}?
+
+    %{release-notes}
+
+    #### Checksums
+
+    <pre>
+    %{tar.filename} (%{tar.humansize})
+       md5sum: %{tar.md5sum}
+       sha1sum: %{tar.sha1sum}
+       sha256sum: %{tar.sha256sum}
+    </pre>

@@ 15,7 15,7 @@ from typing import Iterable, Optional
 class Template(BaseTemplate):
     delimiter = "%"
     idpattern = None
-    braceidpattern = r"(?a:[_a-z][_a-z0-9-.]*)"
+    braceidpattern = r"(?a:\*?[_a-z][_a-z0-9-.]*)"
 
     def substitute(*arg, **kw):
         if not arg:


@@ 30,9 30,16 @@ class Template(BaseTemplate):
         def value(m):
             named = m.group("braced")
             if named is not None:
+                indirection = False
+                named = named.strip()
+                if named[0] == "*":
+                    indirection = True
+                    named = named[1:]
                 value = self.__resolve(chain, named.strip())
                 if value is None:
                     return "%{" + named + "?}"
+                if indirection:
+                    value = Template(value).substitute(*arg, **kw)
                 return str(value)
             if m.group("escaped") is not None:
                 return self.delimiter