Initial parsing and pretty-printing

1 files changed, 92 insertions, 0 deletions

diff --git a/src/print.sml b/src/print.sml
new file mode 100644
index 00000000..6d9019d2
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+++ b/src/print.sml
@@ -0,0 +1,92 @@
+(* Copyright (c) 2008, Adam Chlipala
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * - The names of contributors may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *)
+
+(* Pretty-printing Laconic/Web *)
+
+structure Print :> PRINT = struct
+
+structure SM = TextIOPP
+structure PD = PPDescFn(SM)
+
+type 'a printer = 'a -> PD.pp_desc
+
+fun box ds = PD.hovBox (PD.PPS.Rel 1, ds)
+fun parenIf b d =
+    if b then
+        box [PD.string "(", d, PD.string ")"]
+    else
+        d
+val space = PD.space 1
+
+val out = SM.openOut {dst = TextIO.stdOut, wid = 70}
+val err = SM.openOut {dst = TextIO.stdErr, wid = 70}
+
+fun p_list_sep sep f ls =
+    case ls of
+        [] => PD.string ""
+      | [x] => f x
+      | x :: rest =>
+        let
+            val tokens = foldr (fn (x, tokens) =>
+                                   sep :: f x :: tokens)
+                               [] rest
+        in
+            box (f x :: tokens)
+        end
+fun p_list f = p_list_sep (box [PD.string ",", space]) f
+
+fun fprint f d = (PD.description (f, d);
+                  PD.PPS.flushStream f)
+val print = fprint out
+val eprint = fprint err
+
+fun fpreface f (s, d) =
+    fprint f (PD.hovBox (PD.PPS.Rel 0,
+		         [PD.string s, PD.space 1, d]))
+
+val preface = fpreface out
+val epreface = fpreface err
+
+fun fprefaces f ls =
+    let
+        val len = foldl (fn ((s, _), best) =>
+                            Int.max (size s, best)) 0 ls
+    in
+        app (fn (s, d) =>
+                let
+                    val s = CharVector.tabulate (len - size s,
+                                                 fn _ => #" ")
+                            ^ s ^ ": "
+                in
+                    fpreface f (s, d)
+                end) ls
+    end
+
+val prefaces = fprefaces out
+val eprefaces = fprefaces err
+
+end