https://svn.lrde.epita.fr/svn/xrm/trunk


Index: ChangeLog
from  SIGOURE Benoit  <sigoure.benoit@lrde.epita.fr>

	Add meta-if at Expression level.
	So basically, it is now possible to have a meta-if statement everywhere
	we can find an Expression. /!\ NOTE: meta-if statements at Expression
	level are restricted to one single expressions in the then-part and
	else-part. eg:
	  if some-condition then
	    exp1
	    exp2
	  end
	is *invalid* at Expression level because neither the base language
	nor the extended language provide real statements/sequences of
	expressions.

	Other improvements: PRISM-If statements (cond ? then-part : else-part)
	are now evaluated by prism-desugar when possible. It is also possible
	to reduce the condition of a meta-if statement down to a simple
	Int(_) or Double(_). If that Int(_) or Double(_) is zero, the
	condition will evaluate as False() otherwise True() [like in C].
	NOTE: for Double(_) all tests are performed with a precision of 10^-7
	in other words if 0.000000001 then ... else /*executed*/ end will be
	false.

	* src/str/prism-desugar.str: Add EvalIf and LitToBool.
	* src/str/eval-meta-code.str: Allow if statements to evaluate as
	  integer/real. In this case the behavior is the same as in C: 0 means
	  false and all the other values mean true.
	* src/str/xrm-front.str: Change a debug message to be a notice.
	* src/syn/xrm/XRM-Arrays.sdf: Use XRMRange for array subscripts.
	* src/syn/xrm/XRM-MetaIf.sdf: Add meta-if at the Expression level.
	  Correct EBNF grammar.
	* src/syn/xrm/XRM-MetaFor.sdf: Remove trailing whitespaces.
	* src/syn/xrm/XRM-Expression.sdf: Add XRMRange. This basically just a
	  simple range but it has a different priority in the grammar than
	  the original Range from the base grammar. It is used for array
	  subscripts. Actually XRMRange might not be a wise name for this
	  sorts.
	* tests/xrm/desugar-if.xpm: New.
	* tests/xrm/if-exp.xpm: New.
	* tests/xrm/cond-array-access.xpm: New.
	* tests/xrm/priorities-exp-array-subscript.xpm: New.

 src/str/eval-meta-code.str                   |    4 +-
 src/str/prism-desugar.str                    |   46 +++++++++++++++++++++++++++
 src/str/xrm-front.str                        |    3 -
 src/syn/xrm/XRM-Arrays.sdf                   |   16 ++++-----
 src/syn/xrm/XRM-Expression.sdf               |   27 +++++++++++++++
 src/syn/xrm/XRM-MetaIf.sdf                   |   44 ++++++++++++++++++++++---
 tests/xrm/cond-array-access.xpm              |    4 ++
 tests/xrm/desugar-if.xpm                     |   15 ++++++++
 tests/xrm/if-exp.xpm                         |    7 ++++
 tests/xrm/priorities-exp-array-subscript.xpm |    9 +++++
 10 files changed, 158 insertions(+), 17 deletions(-)

Index: src/str/prism-desugar.str
--- src/str/prism-desugar.str	(revision 52)
+++ src/str/prism-desugar.str	(working copy)
@@ -27,6 +27,7 @@
         <+ EvalAnd <+ EvalOr
         <+ EvalMin <+ EvalMax <+ EvalFloor <+ EvalCeil <+ EvalPow <+ EvalMod
         <+ (EvalStaticRand; IntToDouble)
+        <+ EvalIf
       )
     ; topdown(try(SimplifyDoubles <+ TruncateDouble))
 
@@ -305,6 +306,28 @@
 
 /*
 ** ## ============= ##
+** ## If statements ##
+** ## ============= ##
+*/
+
+rules
+
+  EvalIf:
+    |[ true ? e1 : e2 ]| -> |[ e1 ]|
+
+  EvalIf:
+    |[ false ? e1 : e2 ]| -> |[ e2 ]|
+
+  EvalIf:
+    |[ d ? e1 : e2 ]| -> |[ e1 ]|
+    where <not(compare(real-eq))>(d, 0)
+
+  EvalIf:
+    |[ d ? e1 : e2 ]| -> |[ e2 ]|
+    where <compare(real-eq)>(d, 0)
+
+/*
+** ## ============= ##
 ** ## Eval Builtins ##
 ** ## ============= ##
 **
@@ -348,3 +371,26 @@
           else
             <modS> (i, j) => r
           end
+
+/*
+** ## =========== ##
+** ## Misc. stuff ##
+** ## =========== ##
+*/
+
+rules
+
+  LitToBool:
+    |[ 0 ]| -> |[ false ]|
+
+  LitToBool:
+    |[ i ]| -> |[ true ]|
+    where <not(eq)>(i, "0")
+
+  LitToBool:
+    |[ d ]| -> |[ false ]|
+    where <compare(real-eq)>(d, 0)
+
+  LitToBool:
+    |[ d ]| -> |[ true ]|
+    where <not(compare(real-eq))>(d, 0)
Index: src/str/eval-meta-code.str
--- src/str/eval-meta-code.str	(revision 52)
+++ src/str/eval-meta-code.str	(working copy)
@@ -23,6 +23,7 @@
 imports
   ice
   signatures
+  prism-desugar
 
 strategies
 
@@ -38,7 +39,8 @@
     ?MetaIf(condition, then-part, else-part)
     ///*DEBUG*/; say(!" @@@ eval-meta-if: starting:")
     ///*DEBUG*/; printf(|"     condition = ", condition)
-    ; where(<prism-desugar> condition => condition-value)
+    ; where(<prism-desugar> condition
+           ; try(LitToBool) => condition-value)
     ///*DEBUG*/; printf(|"     condition-value = ", condition-value)
     ; if !condition-value => True() then
         <eval-meta-code> then-part
Index: src/str/xrm-front.str
--- src/str/xrm-front.str	(revision 52)
+++ src/str/xrm-front.str	(working copy)
@@ -42,10 +42,9 @@
     notice-msg(|"transformation pipeline starting")
     ; where(<set-random-seed> (<time>))
     ; xrm-to-prism
-    ; dbg(|"xrm-to-prism finished")
     ; if must-desugar then
         prism-desugar
-        ; dbg(|"prism-desugar finished")
+        ; notice-msg(|"prism-desugar finished")
       end
 
   /** list of available options for xrm-front */
Index: src/syn/xrm/XRM-Arrays.sdf
--- src/syn/xrm/XRM-Arrays.sdf	(revision 52)
+++ src/syn/xrm/XRM-Arrays.sdf	(working copy)
@@ -6,21 +6,21 @@
 
   %% EBNF Grammar: Arrays
   %% ArrayAccess ::=
-  %%      Identifier "[" Range {"," Range} "]"
-  %%    | ArrayAccess "[" Range {"," Range} "]"
+  %%      Identifier "[" XRMRange {"," XRMRange} "]"
+  %%    | ArrayAccess "[" XRMRange {"," XRMRange} "]"
   %%
   %% ArrayAccessPrime ::=
-  %%      Identifier "[" Range {"," Range} "]" "'"
-  %%    | ArrayAccess "[" Range {"," Range} "]" "'"
+  %%      Identifier "[" XRMRange {"," XRMRange} "]" "'"
+  %%    | ArrayAccess "[" XRMRange {"," XRMRange} "]" "'"
 
   sorts ArrayAccess
   context-free syntax
-    Identifier "[" {Range ","}+ "]"	-> ArrayAccess {cons("ArrayAccess")}
-    ArrayAccess "[" {Range ","}+ "]"	-> ArrayAccess {cons("ArrayAccess")}
+    Identifier "[" {XRMRange ","}+ "]"	-> ArrayAccess {cons("ArrayAccess")}
+    ArrayAccess "[" {XRMRange ","}+ "]"	-> ArrayAccess {cons("ArrayAccess")}
 
   sorts ArrayAccessPrime
   context-free syntax
-    ArrayAccess "[" {Range ","}+ "]" "'"
+    ArrayAccess "[" {XRMRange ","}+ "]" "'"
 			-> ArrayAccessPrime {cons("ArrayAccessPrime")}
-    Identifier "[" {Range ","}+ "]" "'"
+    Identifier "[" {XRMRange ","}+ "]" "'"
 			-> ArrayAccessPrime {cons("ArrayAccessPrime")}
Index: src/syn/xrm/XRM-MetaIf.sdf
--- src/syn/xrm/XRM-MetaIf.sdf	(revision 52)
+++ src/syn/xrm/XRM-MetaIf.sdf	(working copy)
@@ -7,23 +7,37 @@
   %% EBNF Grammar: Meta if-then-else
   %% (* if-then-else at top-level *)
   %% ModulesFileSection ::=
-  %%    "if" Expression "then" ModulesFileSection {ModulesFileSection} "end"
+  %%    "if" Expression "then" {ModulesFileSection} "end"
   %%  | "if" Expression "then"
-  %%       ModulesFileSection {ModulesFileSection}
+  %%       {ModulesFileSection}
   %%     "else"
-  %%       ModulesFileSection {ModulesFileSection}
+  %%       {ModulesFileSection}
   %%     "end"
   %%
   %% (* if-then-else inside modules *)
   %% DeclarationOrCommand ::=
-  %%   "if" Expression "then" DeclarationOrCommand {DeclarationOrCommand} "end"
+  %%    "if" Expression "then" {DeclarationOrCommand} "end"
   %%  | "if" Expression "then"
-  %%       DeclarationOrCommand {DeclarationOrCommand}
+  %%       {DeclarationOrCommand}
   %%     "else"
-  %%       DeclarationOrCommand {DeclarationOrCommand}
+  %%       {DeclarationOrCommand}
+  %%     "end"
+  %%
+  %% (* if-then-else inside expressions *)
+  %% (* NOTE: it's not possible to have more than 1 exp in the then-part
+  %%  * and else-part of the meta-if statements for expression. This is
+  %%  * because the current base and extended language don't have real
+  %%  * statements nor sequences of expressions. *)
+  %% Expression ::=
+  %%    "if" Expression "then" Expression "end"
+  %%  | "if" Expression "then"
+  %%       Expression
+  %%     "else"
+  %%       Expression
   %%     "end"
 
   context-free syntax
+
     %% if-then at top-level
     "if" Expression "then" ModulesFileSection* "end"
 			-> ModulesFileSection {cons("MetaIf")}
@@ -36,6 +50,7 @@
     "end"		-> ModulesFileSection {cons("MetaIf")}
 
   context-free syntax
+
     %% if-then within modules
     "if" Expression "then" DeclarationOrCommand* "end"
 			-> DeclarationOrCommand {cons("MetaIf")}
@@ -46,3 +61,20 @@
     "else"
       DeclarationOrCommand*
     "end"		-> DeclarationOrCommand {cons("MetaIf")}
+
+  %% NOTE: it's not possible to have more than 1 exp in the then-part
+  %% and else-part of the meta-if statements for expression. This is
+  %% because the current base and extended language don't have real
+  %% statements nor sequences of expressions.
+  context-free syntax
+
+    %% if-then within expressions
+    "if" Expression "then" Expression "end"
+			-> Expression {cons("MetaIf")}
+
+    %% if-then-else within expressions
+    "if" Expression "then"
+      Expression
+    "else"
+      Expression
+    "end"		-> Expression {cons("MetaIf")}
Index: src/syn/xrm/XRM-MetaFor.sdf
Index: src/syn/xrm/XRM-Expression.sdf
--- src/syn/xrm/XRM-Expression.sdf	(revision 52)
+++ src/syn/xrm/XRM-Expression.sdf	(working copy)
@@ -18,6 +18,9 @@
   %%            (* builtin functions calls using the "func" notation *)
   %%            | "func" "(" "rand" "," Expression {"," Expression} ")"
   %%            | "func" "(" "static_rand" "," Expression {"," Expression} ")"
+  %%
+  %% (* Ranges in XRM with different priority (for array accesses) *)
+  %% XRMRange ::= Expression | Expression ".." Expression
 
   context-free syntax
     ArrayAccess			-> Expression
@@ -39,6 +42,12 @@
     "func" "(" "static_rand" "," {Expression ","}+ ")"
     					-> Expression {cons("StaticRand")}
 
+  %% Ranges in XRM with different priority (for array accesses)
+  sorts XRMRange
+  context-free syntax
+    Expression			-> XRMRange
+    Expression ".." Expression	-> XRMRange {cons("Range")}
+
   %% NOTE: remember: priorities are transitive in SDF.
   %% The following priorities are marked either with "inherited" or "new".
   %% The former means that these priorities are inherited from the base
@@ -71,3 +80,21 @@
   > { %% inherited
       Expression			-> Range
     }
+  > { %% inherited
+      "!" Expression			-> Expression
+    }
+  > {left: %% inherited
+      Expression "&" Expression		-> Expression
+    }
+  > {left: %% inherited
+      Expression "|" Expression		-> Expression
+    }
+  > { %% inherited
+      Expression "?" Expression ":" Expression	-> Expression
+    }
+  > {non-assoc: %% new
+      Expression ".." Expression	-> XRMRange
+    }
+  > { %% new
+      Expression			-> XRMRange
+    }
Index: tests/xrm/desugar-if.xpm
--- tests/xrm/desugar-if.xpm	(revision 0)
+++ tests/xrm/desugar-if.xpm	(revision 0)
@@ -0,0 +1,15 @@
+if 0=1?0:2 then
+  const int success1 = 1;
+  if 0=1?0:2 then
+    const int success2 = 1;
+    if false?0:0 then
+      const int fail1 = 1;
+    else
+      const int success3 = 1;
+    end
+  else
+    const int fail2 = 1;
+  end
+else
+  const int fail3 = 1;
+end
Index: tests/xrm/if-exp.xpm
--- tests/xrm/if-exp.xpm	(revision 0)
+++ tests/xrm/if-exp.xpm	(revision 0)
@@ -0,0 +1,7 @@
+const int N = 3;
+const int success = 1;
+
+module test
+  x : [if true then 0 end..if false then 0 else 42 end];
+  [] x=0 -> x'=if 42 then success else -1 end;
+endmodule
Index: tests/xrm/cond-array-access.xpm
--- tests/xrm/cond-array-access.xpm	(revision 0)
+++ tests/xrm/cond-array-access.xpm	(revision 0)
@@ -0,0 +1,4 @@
+module test
+  x[4] : [0..42] init 0;
+  [] x[-1<0?0:-1]=0 -> true;
+endmodule
Index: tests/xrm/priorities-exp-array-subscript.xpm
--- tests/xrm/priorities-exp-array-subscript.xpm	(revision 0)
+++ tests/xrm/priorities-exp-array-subscript.xpm	(revision 0)
@@ -0,0 +1,9 @@
+module test
+  x[3] : bool init false;
+  y : bool init true;
+  x[4] : [0..42] init 0;
+
+  //[] true -> x[1|1]'=true;
+  [] x[true?2:3]=0 -> true;
+  [] true -> x[0..1&1]'=true;
+endmodule