From 33370917adde77f98b0955843b3222d9838a3fe8 Mon Sep 17 00:00:00 2001
From: Michael Andreen <harv@ruin.nu>
Date: Sun, 26 Feb 2006 20:50:51 +0000
Subject: [PATCH] removed most shift/reduce conflicts by moving EAss from Exp3
 to Exp and thus disallowing many constructs if parenthesis aren't used

---
 Docsyntax.tex  | 9 ++++++---
 Parsyntax.y    | 9 ++++++---
 Printsyntax.hs | 2 +-
 syntax.cf      | 4 ++--
 4 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/Docsyntax.tex b/Docsyntax.tex
index b22e544..a4040dc 100644
--- a/Docsyntax.tex
+++ b/Docsyntax.tex
@@ -80,11 +80,11 @@ All other symbols are terminals.\\
  & {\delimit}  &{\terminal{if}} {\terminal{(}} {\nonterminal{Exp}} {\terminal{)}} {\nonterminal{Stm}} {\terminal{else}} {\nonterminal{Stm}}  \\
  & {\delimit}  &{\terminal{while}} {\terminal{(}} {\nonterminal{Exp}} {\terminal{)}} {\nonterminal{Stm}}  \\
  & {\delimit}  &{\terminal{print}} {\nonterminal{Exp}} {\terminal{;}}  \\
- & {\delimit}  &{\nonterminal{Stm}} {\terminal{;}}  \\
 \end{tabular}\\
 
 \begin{tabular}{lll}
 {\nonterminal{Exp}} & {\arrow}  &{\nonterminal{Exp1}} {\nonterminal{BOp}} {\nonterminal{Exp1}}  \\
+ & {\delimit}  &{\nonterminal{Ident}} {\terminal{{$=$}}} {\nonterminal{Exp}}  \\
  & {\delimit}  &{\nonterminal{Exp1}}  \\
 \end{tabular}\\
 
@@ -102,13 +102,16 @@ All other symbols are terminals.\\
 {\nonterminal{Exp3}} & {\arrow}  &{\nonterminal{Ident}} {\terminal{{$+$}{$+$}}}  \\
  & {\delimit}  &{\nonterminal{Ident}} {\terminal{{$-$}{$-$}}}  \\
  & {\delimit}  &{\nonterminal{Ident}}  \\
- & {\delimit}  &{\nonterminal{Ident}} {\terminal{{$=$}}} {\nonterminal{Exp}}  \\
  & {\delimit}  &{\nonterminal{Integer}}  \\
  & {\delimit}  &{\terminal{{$-$}}} {\nonterminal{Exp3}}  \\
  & {\delimit}  &{\nonterminal{Bool}}  \\
  & {\delimit}  &{\terminal{readInt}}  \\
  & {\delimit}  &{\terminal{readBool}}  \\
- & {\delimit}  &{\terminal{(}} {\nonterminal{Exp}} {\terminal{)}}  \\
+ & {\delimit}  &{\nonterminal{Exp4}}  \\
+\end{tabular}\\
+
+\begin{tabular}{lll}
+{\nonterminal{Exp4}} & {\arrow}  &{\terminal{(}} {\nonterminal{Exp}} {\terminal{)}}  \\
 \end{tabular}\\
 
 \begin{tabular}{lll}
diff --git a/Parsyntax.y b/Parsyntax.y
index 6fef6ba..8bf7c68 100644
--- a/Parsyntax.y
+++ b/Parsyntax.y
@@ -67,11 +67,11 @@ Stm : Type Ident '=' Exp ';' { SDecl $1 $2 $4 }
   | 'if' '(' Exp ')' Stm 'else' Stm { SIf $3 $5 $7 }
   | 'while' '(' Exp ')' Stm { SWhile $3 $5 }
   | 'print' Exp ';' { SPrint $2 }
-  | Stm ';' { $1 }
 
 
 Exp :: { Exp }
 Exp : Exp1 BOp Exp1 { BExp $1 $2 $3 } 
+  | Ident '=' Exp { EAss $1 $3 }
   | Exp1 { $1 }
 
 
@@ -89,13 +89,16 @@ Exp3 :: { Exp }
 Exp3 : Ident '++' { postIncr_ $1 } 
   | Ident '--' { postDecr_ $1 }
   | Ident { EVar $1 }
-  | Ident '=' Exp { EAss $1 $3 }
   | Integer { EInt $1 }
   | '-' Exp3 { ENeg $2 }
   | Bool { EBool $1 }
   | 'readInt' { EReadI }
   | 'readBool' { EReadB }
-  | '(' Exp ')' { $2 }
+  | Exp4 { $1 }
+
+
+Exp4 :: { Exp }
+Exp4 : '(' Exp ')' { $2 } 
 
 
 ListStm :: { [Stm] }
diff --git a/Printsyntax.hs b/Printsyntax.hs
index aeb3258..1d10687 100644
--- a/Printsyntax.hs
+++ b/Printsyntax.hs
@@ -105,7 +105,7 @@ instance Print Exp where
   prt i e = case e of
    BExp exp0 bop exp -> prPrec i 0 (concatD [prt 1 exp0 , prt 0 bop , prt 1 exp])
    EVar id -> prPrec i 3 (concatD [prt 0 id])
-   EAss id exp -> prPrec i 3 (concatD [prt 0 id , doc (showString "=") , prt 0 exp])
+   EAss id exp -> prPrec i 0 (concatD [prt 0 id , doc (showString "=") , prt 0 exp])
    EInt n -> prPrec i 3 (concatD [prt 0 n])
    ENeg exp -> prPrec i 3 (concatD [doc (showString "-") , prt 3 exp])
    EBool bool -> prPrec i 3 (concatD [prt 0 bool])
diff --git a/syntax.cf b/syntax.cf
index fae1234..dc7e659 100644
--- a/syntax.cf
+++ b/syntax.cf
@@ -16,6 +16,7 @@ SWhile.   Stm      ::= "while" "(" Exp ")" Stm ;
 -- SFor.     Stm      ::= "for" "(" Stm Exp ";" Exp ")" Stm ;
 SPrint.   Stm      ::= "print" Exp ";" ;
 
+EAss.     Exp     ::= Ident "=" Exp;
 BExp.     Exp     ::= Exp1 BOp Exp1 ;
 op1.      Exp1    ::= Exp1 Op1 Exp2 ;
 define op1 e1 o e2 = OpExp e1 o e2 ;
@@ -26,7 +27,6 @@ define postIncr i = EPost i Plus ;
 postDecr.    Exp3    ::= Ident "--" ;
 define postDecr i = EPost i Minus ;
 EVar.     Exp3    ::= Ident ;
-EAss.     Exp3    ::= Ident "=" Exp;
 EInt.     Exp3    ::= Integer ;
 ENeg.     Exp3    ::= "-" Exp3 ;
 EBool.    Exp3    ::= Bool ;
@@ -36,7 +36,7 @@ EReadB.   Exp3    ::= "readBool" ;
 coercions Exp 3 ;
 
 
-_.        Stm     ::= Stm ";" ;
+-- _.        Stm     ::= Stm ";" ;
 
 
 terminator Stm "" ;
-- 
2.39.2