Mercurial > urweb

changeset 842:d1b6acaec265

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&& and ||
author Adam Chlipala <adamc@hcoop.net>
date Sun, 07 Jun 2009 12:01:55 -0400
parents 44c2c089ca15
children 9f0ea203a1ca
files src/urweb.grm src/urweb.lex
diffstat 2 files changed, 24 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/src/urweb.grm	Sun Jun 07 11:13:18 2009 -0400
+++ b/src/urweb.grm	Sun Jun 07 12:01:55 2009 -0400
@@ -202,7 +202,7 @@
  | STRUCTURE | SIGNATURE | STRUCT | SIG | END | FUNCTOR | WHERE | EXTERN | SQL
  | INCLUDE | OPEN | CONSTRAINT | CONSTRAINTS | EXPORT | TABLE | SEQUENCE | VIEW
  | COOKIE | STYLE
- | CASE | IF | THEN | ELSE
+ | CASE | IF | THEN | ELSE | ANDALSO | ORELSE
 
  | XML_BEGIN of string | XML_END | XML_BEGIN_END of string
  | NOTAGS of string 
@@ -365,6 +365,8 @@
 %right SEMI
 %nonassoc LARROW
 %nonassoc IF THEN ELSE
+%left ANDALSO
+%left ORELSE
 %nonassoc DARROW
 %nonassoc COLON
 %nonassoc DCOLON TCOLON
@@ -944,6 +946,23 @@
        | eexp GT eexp                   (native_op ("gt", eexp1, eexp2, s (eexp1left, eexp2right)))
        | eexp GE eexp                   (native_op ("ge", eexp1, eexp2, s (eexp1left, eexp2right)))
 
+       | eexp ANDALSO eexp              (let
+                                             val loc = s (eexp1left, eexp2right)
+                                         in
+                                             (ECase (eexp1, [((PCon (["Basis"], "True", NONE), loc),
+                                                              eexp2),
+                                                             ((PCon (["Basis"], "False", NONE), loc),
+                                                              (EVar (["Basis"], "False", Infer), loc))]), loc)
+                                         end)
+       | eexp ORELSE eexp               (let
+                                             val loc = s (eexp1left, eexp2right)
+                                         in
+                                             (ECase (eexp1, [((PCon (["Basis"], "True", NONE), loc),
+                                                              (EVar (["Basis"], "True", Infer), loc)),
+                                                             ((PCon (["Basis"], "False", NONE), loc),
+                                                              eexp2)]), loc)
+                                         end)
+
        | eexp PLUSPLUS eexp             (EConcat (eexp1, eexp2), s (eexp1left, eexp2right))
 
        | eexp CARET eexp                (native_op ("strcat", eexp1, eexp2, s (eexp1left, eexp2right)))
--- a/src/urweb.lex	Sun Jun 07 11:13:18 2009 -0400
+++ b/src/urweb.lex	Sun Jun 07 12:01:55 2009 -0400
@@ -333,6 +333,9 @@
 <INITIAL> "---"       => (Tokens.MINUSMINUSMINUS (pos yypos, pos yypos + size yytext));
 <INITIAL> "^"         => (Tokens.CARET (pos yypos, pos yypos + size yytext));
 
+<INITIAL> "&&"        => (Tokens.ANDALSO (pos yypos, pos yypos + size yytext));
+<INITIAL> "||"        => (Tokens.ORELSE (pos yypos, pos yypos + size yytext));
+
 <INITIAL> "="         => (Tokens.EQ (pos yypos, pos yypos + size yytext));
 <INITIAL> "<>"        => (Tokens.NE (pos yypos, pos yypos + size yytext));
 <INITIAL> "<"         => (Tokens.LT (pos yypos, pos yypos + size yytext));
@@ -377,6 +380,7 @@
 <INITIAL> "then"      => (Tokens.THEN (pos yypos, pos yypos + size yytext));
 <INITIAL> "else"      => (Tokens.ELSE (pos yypos, pos yypos + size yytext));
 
+
 <INITIAL> "structure" => (Tokens.STRUCTURE (pos yypos, pos yypos + size yytext));
 <INITIAL> "signature" => (Tokens.SIGNATURE (pos yypos, pos yypos + size yytext));
 <INITIAL> "struct"    => (Tokens.STRUCT (pos yypos, pos yypos + size yytext));