Fixes for optional stage handling, add rudimentary support for packag…

…e mixins

lib/rules.lua

@@ -186,11 +186,24 @@ template {
     }
 }
 
+template {
+    match = {
+        name  = value,
+        build = some
+    },
+    apply = {
+        build = {
+            work_dir = path { from('jagen', 'build_dir'), value }
+        }
+    }
+}
+
 -- stage: clean
 
 template {
-    match = {
-        source = some
+    match = anyof {
+        { source = some },
+        { build  = some }
     },
     apply = {
         stage = { clean = {} }
@@ -200,12 +213,14 @@ template {
 -- update
 
 template {
-    match = { source = { scm = true } },
+    match = {
+        source = { scm = true }
+    },
     apply = {
         stage = {
             update = {
                 inputs = { stage 'clean' },
-                work_dir = from('jagen', 'build_dir')
+                work_dir = from('jagen', 'src_dir')
             }
         }
     }
@@ -230,19 +245,17 @@ template {
 template {
     match = {
         patches = some,
-        source  = { dir = value 'source.dir' },
     },
     apply = {
         stage = {
             patch = {
                 inputs = {
-                    from('<self>', anyof {
+                    from(self, anyof {
                             stage 'update',
                             stage 'unpack',
                             stage 'clean'
                         })
-                },
-                work_dir = value 'source.dir'
+                }
             }
         }
     }
@@ -297,22 +310,22 @@ template {
     match = {
         build = {
             type = some,
-            dir  = some
+            dir  = value 'build.dir'
         }
     },
     apply = {
         stage = {
             configure = {
                 inputs = {
-                    anyof {
-                        stage 'patch',
-                        stage 'update',
-                        stage 'unpack',
-                        stage 'clean'
-                    }
+                    from(self, anyof {
+                            stage 'patch',
+                            stage 'update',
+                            stage 'unpack',
+                            stage 'clean'
+                        })
                 },
-                work_dir = expand '${build.dir}'
-            } 
+                work_dir = value 'build.dir'
+            }
         }
     }
 }

src/Engine.lua

@@ -123,13 +123,30 @@ function Engine:process_module(module, pkg)
             self:process_use(spec, pkg)
         end
     end
+    for i = 1, #env.packages do
+        local pkg = env.packages[i]
+        for ref in each(pkg.extends) do
+            local parent = self.packages[ref]
+            if parent then
+                local this = copy(parent)
+                this.abstract = nil
+                this.config = nil
+                this:merge(pkg, { env = pkg })
+                env.packages[i] = this
+                env.packages[this.ref] = this
+            else
+                error(format('package %s extends %s which is not defined',
+                    pkg.ref, ref))
+            end
+        end
+    end
     self:apply_templates(env)
 end
 
 function Engine:process_package(rule, env)
     local pkg = self.packages[rule.ref]
     if pkg then
-        Log.debug1('process package %s: merge with existing instance', rule.ref)
+        Log.debug1('process package %s: merge with an existing instance', rule.ref)
         pkg:merge(rule, { env = pkg })
     else
         Log.debug1('process package %s: add new instance', rule.ref)

src/Module.lua

@@ -406,7 +406,7 @@ function Module.env.from(expr, key)
             ref = ref(state)
         end
         local pkg
-        if ref == '<self>' then
+        if ref == nil then
             pkg = state.self
         else
             pkg = state.packages[ref]
@@ -423,6 +423,10 @@ function Module.env.from(expr, key)
             elseif keytype == 'nil' then
                 return pkg
             end
+        else
+            if debug then
+                Log.debug1('from %s: not found', ref)
+            end
         end
     end
 end

src/Package.lua

@@ -38,11 +38,20 @@ function Package:parse(rule)
         rule.name = rule[1]
         table.remove(rule, 1)
     end
+    if type(rule[2]) == 'string' then
+        rule.config = rule[1]
+        table.remove(rule, 1)
+    end
+
+    if rule.name and rule.config then
+        rule.ref = string.format('%s:%s', rule.name, rule.config)
+    else
+        rule.ref = rule.name or rule.config
+    end
 
-    rule.ref = rule.name
     rule.source = Source:parse(rule.source)
 
-    for key in each { 'class', 'uses' } do
+    for key in each { 'class', 'uses', 'extends' } do
         local value = rule[key]
         if type(value) == 'string' then
             rule[key] = { value }