feat: sequencing of expressions with newline to same indent (#11)

feat: sequencing of expressions with newline to same indent

  Also revised README to reflect greater emphasis on streams.
  Haskell code generation unsurprisingly required a fairly significant
  rework.

  Resolves #3.

Co-authored-by: Glen Whitney <glen@studioinfinity.org>
Reviewed-on: #11
Co-Authored-By: Glen Whitney <glen@nobody@nowhere.net>
Co-Committed-By: Glen Whitney <glen@nobody@nowhere.net>

trans/haskell.str

@@ -17,33 +17,32 @@ rules
   hs: TopLevel((c,p)) -> $[import System.IO
   data IOStream = StdIO
 
-  stdio :: IO IOStream
-  stdio = return StdIO
-
-  receives :: Show b => IO a -> b -> IO a
-  receives s d = do
-    temp <- s
+  gets :: Show b => a -> b -> IO a
+  gets s d = do
     putStr(show d)
-    return temp
+    return s
 
   main = do
     [p]return [c]]
 
-  hs: Stdio() -> ("stdio", "")
+  hs: Stream() -> ("StdIO", "")
   hs: Int(x) -> (x, "")
-  hs: Sum((c,p)) -> ($[sum [c]], p)
-  hs: Receives((c, p), (d, s)) -> ($[[c] `receives` [d]], <conc-strings>(p,s))
-  hs: Enters((c, p), (d, s)) -> <hsenter>(c,d,<conc-strings>(p,s),<newname>"fos")
+  hs: Sum( (c, p), (d, q)) -> ($[([c] + [d])], <conc-strings>(p,q))
+  hs: Gets((c, p), (d, q)) -> <hsget>(c,d,<conc-strings>(p,q),<newname>"fosgt")
 
-  hsenter: (x, s, p, v) -> (v, <concat-strings>[$[[p]let [v] = [x]], "\n",
-                               $[[s] `receives` [v]], "\n"])
+  hsget: (s, x, p, v) -> (v, <concat-strings>[p, $[[v] <- [s] `gets` [x]],
+                                              "\n"])
 
-  hslist: x -> (<map(Fst); join(|", "); brack>x, <map(Snd); concat-strings>x)
-  brack: x -> $<[<x>]>
+  hs: To(  (c, p), (d, q)) -> <hsto>(c,d,<conc-strings>(p,q),<newname>"fosto")
+
+  hsto: (x, s, p, v) -> (v, <concat-strings>[p, $[let [v] = [x]], "\n",
+                               $[[s] `gets` [v]], "\n"])
+
+  hs: Sequence(l) -> (<last; Fst>l, <map(Snd); concat-strings>l)
 
 strategies
 
-  haskell = bottomup(try(hs <+ hslist))
+  haskell = bottomup(try(hs))
 
   // Interface haskell code generation with editor services and file system
   to-haskell: (selected, _, _, path, project-path) -> (filename, result)

trans/javascript.str

@@ -7,25 +7,24 @@ signature
 
 rules
   js: TopLevel(x) -> $[const Stdio = {
-    receives: v => { process.stdout.write(String(v)); return Stdio; },
+    gets: v => { process.stdout.write(String(v)); return Stdio; },
   }
-  function forwards(data, strm) {
-    strm.receives(data);
+  function to(data, strm) {
+    strm.gets(data);
     return data;
   }
   [x]]
 
-  js: Stdio() -> $[Stdio]
+  js: Stream() -> $[Stdio]
   js: Int(x) -> x
-  js: Sum(x) -> $[[x].reduce((v,w) => v+w)]
-  js: Receives(x, y) -> $[[x].receives([y])]
-  js: Enters(x, y) -> $[forwards([x],[y])]
-
-  jslist: x -> $<[<<join(|", ")>x>]>
+  js: Sum(x,y) -> $[[x] + [y]]
+  js: Gets(x, y) -> $[[x].gets([y])]
+  js: To(x, y) -> $[to([x],[y])]
+  js: Sequence(l) -> <join(|";\n")>l
 
 strategies
 
-  javascript = bottomup(try(js <+ jslist))
+  javascript = bottomup(try(js))
 
   // Interface javascript code generation with editor services and file system
   to-javascript: (selected, _, _, path, project-path) -> (filename, result)

trans/python.str

@@ -9,26 +9,25 @@ rules
 
   py: TopLevel(x) -> $[import sys
   class StdioC:
-    def receives(self, v):
+    def gets(self, v):
       print(v, file=sys.stdout, end='')
       return self
-  def forwards(data,strm):
-    strm.receives(data)
+  def to(data,strm):
+    strm.gets(data)
     return data
   Stdio = StdioC()
   [x]]
 
-  py: Stdio() -> $[Stdio]
-  py: Int(x) -> x
-  py: Sum(x) -> $[sum([x])]
-  py: Receives(x, y) -> $[[x].receives([y])]
-  py: Enters(x, y) -> $[forwards([x],[y])]
-
-  pylist: x -> $<[<<join(|", ")>x>]>
+  py: Stream()    -> $[Stdio]
+  py: Int(x)      -> x
+  py: Sum(x,y)    -> $[[x] + [y]]
+  py: Gets(x, y)  -> $[[x].gets([y])]
+  py: To(x, y)    -> $[to([x],[y])]
+  py: Sequence(l) -> <join(|"\n")>l
 
 strategies
 
-  python = bottomup(try(py <+ pylist))
+  python = bottomup(try(py))
 
   // Interface python code generation with editor services and file system
   to-python: (selected, _, _, path, project-path) -> (filename, result)

trans/util.str

@@ -3,7 +3,7 @@ imports libstrategolib
 
 rules
   join(|infix) : [] -> ""
-  join(|infix) : [x | xs] -> $[[x][<prejoin(|infix)>xs]]
+  join(|infix) : [x | xs] -> <conc-strings>(x, <prejoin(|infix)>xs)
 
   prejoin(|infix) : [] -> ""
-  prejoin(|infix) : [x | xs] -> $[[infix][x][<prejoin(|infix)>xs]]
+  prejoin(|infix) : [x | xs] -> <concat-strings>[infix,x,<prejoin(|infix)>xs]