kfl · melsman · Mar 20, 2021 · Mar 20, 2021
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
@@ -0,0 +1,68 @@
+name: CI
+
+on:
+
+  push:
+    branches: [ master ]
+
+  pull_request:
+    branches: [ master ]
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+
+  build-test:
+
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+        mlcomp: [mlkit, mlton]
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+
+      - uses: actions/checkout@v2
+
+      - name: Setup environment
+        run: |
+          echo "OS=$(uname -s | tr '[:upper:]' '[:lower:]')" >> $GITHUB_ENV
+          echo "RUNHOME=$(echo $HOME)" >> $GITHUB_ENV
+
+      - name: Install MLKit and smlpkg
+        working-directory: ${{ env.RUNHOME }}
+        run: |
+          echo "[OS: $OS, HOME: $RUNHOME]"
+          wget https://github.com/diku-dk/smlpkg/releases/download/v0.1.4/smlpkg-bin-dist-${{env.OS}}.tgz
+          tar xzf smlpkg-bin-dist-${{env.OS}}.tgz
+          echo "$HOME/smlpkg-bin-dist-${{env.OS}}/bin" >> $GITHUB_PATH
+          wget https://github.com/melsman/mlkit/releases/download/v4.5.4/mlkit-bin-dist-${{env.OS}}.tgz
+          tar xzf mlkit-bin-dist-${{env.OS}}.tgz
+          echo "$HOME/mlkit-bin-dist-${{env.OS}}/bin" >> $GITHUB_PATH
+          mkdir -p .mlkit
+          echo "SML_LIB $HOME/mlkit-bin-dist-${{env.OS}}/lib/mlkit" > .mlkit/mlb-path-map
+
+      - name: Check
+        run: |
+          mlkit --version
+          smlpkg --version
+
+      - name: Install MLton (linux)
+        if: ${{ env.OS == 'linux' && matrix.mlcomp == 'mlton' }}
+        run: |
+          sudo apt-get install -y mlton
+          mlton
+
+      - name: Install MLton (macos)
+        if: ${{ env.OS == 'darwin' && matrix.mlcomp == 'mlton' }}
+        run: |
+          brew install mlton
+          mlton
+
+      - name: Build
+        run: MLCOMP=${{ matrix.mlcomp }} make clean all
+
+      - name: Run tests
+        run: MLCOMP=${{ matrix.mlcomp }} make test
diff --git a/Makefile b/Makefile
@@ -0,0 +1,12 @@
+.PHONY: all
+all:
+	$(MAKE) -C lib/github.com/kfl/wpp all
+
+.PHONY: test
+test:
+	$(MAKE) -C lib/github.com/kfl/wpp test
+
+.PHONY: clean
+clean:
+	$(MAKE) -C lib/github.com/kfl/wpp clean
+	rm -rf MLB *~ .*~
diff --git a/README.md b/README.md
@@ -1,4 +1,41 @@
-wpp
-===
+# wpp [![CI](https://github.com/kfl/wpl/workflows/CI/badge.svg)](https://github.com/kfl/wpp/actions)
 
- A Pretty Printer, based on Philip Wadler's "A prettier printer".    But heavily modified to be efficient in a strict language.
+A Pretty Printer for Standard ML, based on Philip Wadler's "A prettier
+printer". But heavily modified to be efficient in a strict language.
+
+## Overview of MLB files
+
+- `lib/github.com/kfl/wpp/wpp.mlb`:
+
+  - **signature** [`Wpp`](lib/github.com/kfl/wpp/Wpp.sig)
+  - **structure** `Wpp`
+  - **structure** `Utility`
+
+## Use of the package
+
+This library is set up to work well with the SML package manager
+[smlpkg](https://github.com/diku-dk/smlpkg).  To use the package, in
+the root of your project directory, execute the command:
+
+```
+$ smlpkg add github.com/kfl/wpp
+```
+
+This command will add a _requirement_ (a line) to the `sml.pkg` file in your
+project directory (and create the file, if there is no file `sml.pkg`
+already).
+
+To download the library into the directory
+`lib/github.com/kfl/wpp`, execute the command:
+
+```
+$ smlpkg sync
+```
+
+You can now reference the `mlb`-file using relative paths from within
+your project's `mlb`-files.
+
+Notice that you can choose either to treat the downloaded package as
+part of your own project sources (vendoring) or you can add the
+`sml.pkg` file to your project sources and make the `smlpkg sync`
+command part of your build process.
diff --git a/lib/github.com/kfl/wpp/.gitignore b/lib/github.com/kfl/wpp/.gitignore
@@ -0,0 +1,5 @@
+*.res
+*.exe
+*~
+*.out
+MLB
diff --git a/lib/github.com/kfl/wpp/Makefile b/lib/github.com/kfl/wpp/Makefile
@@ -0,0 +1,14 @@
+MLCOMP ?= mlkit
+
+.PHONY: all
+all:
+	$(MLCOMP) -output wpp.exe wpp.mlb
+
+.PHONY: test
+test:
+	$(MAKE) -C test test
+
+.PHONY: clean
+clean:
+	$(MAKE) -C test clean
+	rm -rf MLB *~ wpp.exe
diff --git a/lib/github.com/kfl/wpp/Wpp.sig b/lib/github.com/kfl/wpp/Wpp.sig
@@ -8,6 +8,7 @@
    your choice, the licence can be obtained at
    http://www.gnu.org/copyleft/lgpl.html
 *)
+
 signature  Wpp =
   sig
     type doc
@@ -34,7 +35,6 @@ signature  Wpp =
     val real     : real  -> doc          (* an ML real constant *)
     val bool     : bool  -> doc          (* a boolean *)
 
-
     val toString    : int -> doc -> string
     val toOutStream : int -> TextIO.outstream -> doc -> unit
     val toFile      : int -> string -> doc -> unit

diff --git a/lib/github.com/kfl/wpp/Wpp.sml b/lib/github.com/kfl/wpp/Wpp.sml
@@ -13,27 +13,27 @@ struct
     infixr 6 ^^
 
     datatype doc =
-	      NIL
+        NIL
       | APPEND of doc * doc
       | NEST   of int * doc
       | TEXT   of string
       | BREAK  of int * int
       | NEWLINE
       | GROUP  of doc
 
-    fun op^^ p     = case p of
-                       (NIL,NIL) => NIL
-                     | (NIL, y)  => y
-                     | (x, NIL)  => x
-                     | _         => APPEND p
+    fun op^^ p = case p of
+                     (NIL,NIL) => NIL
+                   | (NIL, y)  => y
+                   | (x, NIL)  => x
+                   | _         => APPEND p
 
     val empty    = NIL
     fun nest i x = NEST(i,x)
     val text     = TEXT
     fun break sp off = BREAK(sp, off)
     val line     = BREAK (1,0)
     val newline  = NEWLINE
-    fun group x	 = GROUP x
+    fun group x  = GROUP x
 
     (*** Derived functions ***)
     val concat     = List.foldr op^^ empty
@@ -52,16 +52,14 @@ struct
     val real  = fromConv Real.toString
     fun bool b = if b then text "true" else text "false"
 
-
-
     (*** Formating of docs ***)
 
     val nlsize = String.size "\n"
     fun spaces outs s i  = outs s (StringCvt.padLeft #" " i "")
     fun nlspace outs s i = outs s (StringCvt.padRight #" " (i+nlsize) "\n")
 
     local
-	      datatype mode = Flat | Break
+        datatype mode = Flat | Break
 
         fun fitting [] left                       = true
           | fitting ((i, mode, doc) :: rest) left =

diff --git a/lib/github.com/kfl/wpp/test/.gitignore b/lib/github.com/kfl/wpp/test/.gitignore
@@ -0,0 +1,5 @@
+*.res
+*.exe
+*~
+*.out
+MLB
diff --git a/lib/github.com/kfl/wpp/test/Makefile b/lib/github.com/kfl/wpp/test/Makefile
@@ -0,0 +1,31 @@
+
+MLCOMP ?= mlkit
+
+.PHONY: test
+test: example.res
+	cat $^
+
+%.res: %.out
+	@(diff -aq $< $<.ok > /dev/null 2>&1; \
+         if [ $$? -eq 0 ]; then \
+             echo "OK:  $*" > $@ \
+         ; else \
+             if [ -e $<.ok ]; then \
+                echo "ERR: $* - file $< differs from $<.ok"; \
+                echo "ERR: $* - file $< differs from $<.ok" > $@ \
+             ; else \
+                echo "ERR: $* - file $<.ok does not exist"; \
+                echo "ERR: $* - file $<.ok does not exist" > $@ \
+             ; fi \
+             ; exit 1 \
+         ;fi)
+
+%.out: %.exe
+	./$< > $@
+
+%.exe: %.mlb %.sml
+	$(MLCOMP) -output $@ $<
+
+.PHONY: clean
+clean:
+	rm -rf MLB *.out *~ *.exe *.res run
diff --git a/lib/github.com/kfl/wpp/test/example.mlb b/lib/github.com/kfl/wpp/test/example.mlb
@@ -0,0 +1,6 @@
+local
+  $(SML_LIB)/basis/basis.mlb
+  ../wpp.mlb
+in
+  example.sml
+end
diff --git a/lib/github.com/kfl/wpp/test/example.out.ok b/lib/github.com/kfl/wpp/test/example.out.ok
@@ -0,0 +1,44 @@
+maxS50:
+if (x > y) then (x + 1) else (y * z)
+
+maxS30:
+if (x > y)
+then (x + 1)
+else (y * z)
+
+maxS10:
+if (x > y)
+then
+  (x + 1)
+else
+  (y * z)
+
+nestS50:
+if (x > y)
+then (x + 1)
+else if (x > y) then (x + 1) else (y * z)
+
+nestS30:
+if (x > y)
+then (x + 1)
+else
+  if (x > y)
+  then (x + 1)
+  else (y * z)
+
+nestS10:
+if (x > y)
+then
+  (x + 1)
+else
+  if
+    (x
+     >
+     y)
+  then
+    (x
+     +
+     1)
+  else
+    (y * z)
+
diff --git a/lib/github.com/kfl/wpp/test/example.sml b/lib/github.com/kfl/wpp/test/example.sml
@@ -0,0 +1,62 @@
+structure Example =
+struct
+
+(*
+Small demonstration of how to use Wpp and the utilities.
+
+An often occurring challenge is to format if-then-else nicely, so that
+is mainly what we'll demonstrate,
+*)
+
+local
+    structure U = Utility
+    val $ = U.$
+    val ^+^ = U.^+^
+    infix ^+^
+in
+
+datatype Ast = Var  of string
+             | Lit  of int
+             | Opr  of Ast * string * Ast
+             | Cond of Ast * Ast * Ast
+
+fun toDoc ast =
+    case ast of
+        Var v                => $v
+      | Lit n                => Wpp.int n
+      | Opr(x, opr, y)       => U.bin toDoc ($opr) (x, y)
+      | Cond(test, pos, neg) =>
+        Wpp.group (U.spread [ U.block 2 ($"if"   ^+^ toDoc test)
+                            , U.block 2 ($"then" ^+^ toDoc pos)
+                            , U.block 2 ($"else" ^+^ toDoc neg)])
+
+(* AST for `if (x > y) then x+1 else y*z` *)
+val maxEx = Cond(Opr(Var"x", ">", Var"y"),
+                 Opr(Var"x", "+", Lit 1),
+                 Opr(Var"y", "*", Var"z"))
+val maxDoc = toDoc maxEx
+val maxS50 = Wpp.toString 50 maxDoc (* equals "if (x > y) then (x + 1) else (y * z)\n" *)
+val maxS30 = Wpp.toString 30 maxDoc (* equals "if (x > y)\nthen (x + 1)\nelse (y * z)\n" *)
+val maxS10 = Wpp.toString 10 maxDoc (* equals "if (x > y)\nthen\n  (x + 1)\nelse\n  (y * z)\n" *)
+
+
+val nested = Cond(Opr(Var"x", ">", Var"y"),
+                  Opr(Var"x", "+", Lit 1),
+                  maxEx)
+val nestDoc = toDoc nested
+val nestS50 = Wpp.toString 50 nestDoc
+val nestS30 = Wpp.toString 30 nestDoc
+val nestS10 = Wpp.toString 10 nestDoc
+
+fun pr_test t s = print (t ^ ":\n" ^ s ^ "\n")
+
+val () = pr_test "maxS50" maxS50
+val () = pr_test "maxS30" maxS30
+val () = pr_test "maxS10" maxS10
+
+val () = pr_test "nestS50" nestS50
+val () = pr_test "nestS30" nestS30
+val () = pr_test "nestS10" nestS10
+
+end
+end
diff --git a/lib/github.com/kfl/wpp/wpp.mlb b/lib/github.com/kfl/wpp/wpp.mlb
@@ -0,0 +1,7 @@
+local
+  $(SML_LIB)/basis/basis.mlb
+in
+  Wpp.sig
+  Wpp.sml
+  Utility.sml
+end
-Original file line number
+Diff line change
@@ -0,0 +1,5 @@
+    *.res
+    *.exe
+    *~
+    *.out
+    MLB