update purescript template, only generates new file when content changes

2 files changed, 11 insertions, 4 deletions

diff --git a/ddl/Generate.hs b/ddl/Generate.hs
index 7e7d3ca..c407510 100644
--- a/ddl/Generate.hs
+++ b/ddl/Generate.hs
@@ -61,6 +61,13 @@ main = do
                 , "swiftType"       @: swiftType aliasMap
                 , "hasEnumConstructor" @: hasEnumConstructor
                 ]
+            writeFileIfDiffer fname txt = doesFileExist fname >>= \case
+              False -> writeFile fname txt
+              True  -> do
+                        oldTxt <- readFile fname
+                        case (lines oldTxt, lines txt) of
+                          (_ : oldTime : old, _ : newTime : new) | old == new -> return () -- NOTE: timestamp is always in the second line
+                          _ -> writeFile fname txt
 
         -- Haskell
         either error (\x -> writeFile ("out/" ++ name ++ ".hs") $ LText.unpack x) $ dataHs >>= (\t -> eitherRenderWith mylib t env)
diff --git a/ddl/templates/data.purs.ede b/ddl/templates/data.purs.ede
index 490050a..f21a6bc 100644
--- a/ddl/templates/data.purs.ede
+++ b/ddl/templates/data.purs.ede
@@ -4,11 +4,12 @@
 module {{ moduleName }} where
 import Prelude
 import Data.Generic
+import Data.Either (Either(..))
 import Data.Maybe (Maybe(..))
 import Data.StrMap (StrMap(..))
 import Data.Map (Map(..))
 import Data.List (List(..))
-import Linear
+import LinearBase
 
 import Data.Argonaut.Encode.Combinators ((~>), (:=))
 import Data.Argonaut.Decode.Combinators ((.?))
@@ -16,7 +17,6 @@ import Data.Argonaut.Core (jsonEmptyObject)
 import Data.Argonaut.Printer (printJson)
 import Data.Argonaut.Encode (class EncodeJson, encodeJson)
 import Data.Argonaut.Decode (class DecodeJson, decodeJson)
-import Partial.Unsafe (unsafeCrashWith)
 
 {% for m in imports %}
 import {{ m.value }}
@@ -39,7 +39,7 @@ type {{ t.value.aliasName }} = {{ t.value.aliasType | psType }}
 
 {% endcase %}
 {% endfor %}
-{% for t in definitions %}{% let l = t.value.instances | length %}{% if l > 0 %}{# FIXME!!! #}
+{% for t in definitions %}{% let l = t.value.instances | length %}{% if l < 0 %}{# FIXME!!! #}
 derive instance generic{{ t.value.dataName }} :: Generic {{ t.value.dataName }}
 instance show{{ t.value.dataName }} :: Show {{ t.value.dataName }} where show = gShow
 instance eq{{ t.value.dataName }}   :: Eq {{ t.value.dataName }}   where eq = gEq
@@ -66,6 +66,6 @@ instance decodeJson{{ t.value.dataName }} :: DecodeJson {{ t.value.dataName }} w
           {% if f.first %}{ {% else %}, {%endif%}{{ f.value.fieldName }}:{{ f.value.fieldName }}{% endfor %}
           } {% else %}
       "{{ c.value.name }}" -> {% for f in c.value.fields %}{% if f.first %}{{ c.value.name }} <$>{% else %} <*>{% endif %} obj .? "arg{{ f.index0 }}"{%else%}pure {{ c.value.name }}{% endfor %}{% endif %}{% endfor %}
-      _ -> unsafeCrashWith "decodeJson @ {{ t.value.dataName }}"
+      _ -> Left ("decodeJson{{ t.value.dataName }} - unknown tag: " <> tag)
 
 {% endfor %}