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SandBoxLexicalScope
  
last edited 12 years ago by test1

Edit detail for SandBoxLexicalScope revision 9 of 12
1 2 3 4 5 6 7 8 9 10 11 12
Editor: Bill Page
Time: 2008/05/15 17:16:35 GMT-7
Note: union 
added:
An example of Union for branches of 'if' that yield different
types:
\begin{spad}
)abbrev domain BBB Bbb
Bbb: with
    foo: Integer -> Integer
  == add
    foo(a: Integer): Integer ==
     x:Union(Integer,Float)
     if a>0 then
         x := 1
     else
         x := 2.3
     x case Integer => (x*x)::Integer
     wholePart(x*x)
\end{spad}

\begin{axiom}
foo(0)
foo(1)
\end{axiom}

j is referenced out of scope 

axiom
for i in 1..5 repeat
        j:Integer := i^2
        output(i::OutputForm)$OutputPackage
   1
   2
   3
   4
   5
Type: Void
axiom
output(j::OutputForm)$OutputPackage
   25
Type: Void

The code above returns an error in OpenAxiom? 1.2.0 (Revision >= 563).

It sould be written like this: 

axiom
j: Integer
Type: Void
axiom
for i in 1..5 repeat
        j := i^2
        output(i::OutputForm)$OutputPackage
   1
   2
   3
   4
   5
Type: Void
axiom
output(j::OutputForm)$OutputPackage
   25
Type: Void

Oddly, using j out of scope is also allowed in Aldor: 

aldor
#pile
#include "axiom"
import from PositiveInteger
CheckScope1(): with
    checkscope1: () -> PositiveInteger
  == add
    checkscope1():PositiveInteger ==
      for i in 1..5 repeat
        j:PositiveInteger := i^2
        --output(i::OutputForm)$OutputPackage
      --output(j::OutputForm)$OutputPackage
      j
aldor
   Compiling FriCAS source code from file 
      /var/zope2/var/LatexWiki/8452782754204589047-25px003.as using 
      AXIOM-XL compiler and options 
-O -Fasy -Fao -Flsp -laxiom -Mno-AXL_W_WillObsolete -DAxiom -Y $AXIOM/algebra
      Use the system command )set compiler args to change these 
      options.
#1 (Warning) Deprecated message prefix: use `ALDOR_' instead of `_AXL'
   Compiling Lisp source code from file 
      ./8452782754204589047-25px003.lsp
   Issuing )library command for 8452782754204589047-25px003
   Reading /var/zope2/var/LatexWiki/8452782754204589047-25px003.asy
   CheckScope1 is now explicitly exposed in frame initial 
   CheckScope1 will be automatically loaded when needed from 
      /var/zope2/var/LatexWiki/8452782754204589047-25px003

axiom
checkscope1()
LatexWiki Image(1)
Type: PositiveInteger?

aldor
#pile
#include "axiom"
import from PositiveInteger
CheckScope2(): with
    checkscope2: () -> PositiveInteger
  == add
    checkscope2():PositiveInteger ==
      local j:PositiveInteger
      for i in 1..5 repeat
        j := i^2
        --output(i::OutputForm)
        --output(j::OutputForm)$OutputPackage
      j
aldor
   Compiling FriCAS source code from file 
      /var/zope2/var/LatexWiki/8264748852590484820-25px005.as using 
      AXIOM-XL compiler and options 
-O -Fasy -Fao -Flsp -laxiom -Mno-AXL_W_WillObsolete -DAxiom -Y $AXIOM/algebra
      Use the system command )set compiler args to change these 
      options.
#1 (Warning) Deprecated message prefix: use `ALDOR_' instead of `_AXL'
   Compiling Lisp source code from file 
      ./8264748852590484820-25px005.lsp
   Issuing )library command for 8264748852590484820-25px005
   Reading /var/zope2/var/LatexWiki/8264748852590484820-25px005.asy
   CheckScope2 is now explicitly exposed in frame initial 
   CheckScope2 will be automatically loaded when needed from 
      /var/zope2/var/LatexWiki/8264748852590484820-25px005

axiom
checkscope2()
LatexWiki Image(2)
Type: PositiveInteger?

Ralf Hemmecke wrote:

Ooops, what in would be illegal? I just had to replace (as I said) the braces by parentheses, since parens are used to group sequences of commands. (Same as braces in Aldor.)

spad
)abbrev domain AAA Aaa
Aaa: with
    bar: Integer -> Integer
  == add
    (x: Integer := 4; y: Integer := 3)
    bar(a: Integer): Integer == x + a + z
    z: Integer := 3 + y
spad
   Compiling FriCAS source code from file 
      /var/zope2/var/LatexWiki/2292316700013189339-25px007.spad using 
      old system compiler.
   AAA abbreviates domain Aaa 
------------------------------------------------------------------------
   initializing NRLIB AAA for Aaa 
   compiling into NRLIB AAA 
   compiling exported bar : Integer -> Integer
****** comp fails at level 2 with expression: ******
error in function bar 
(+ (+ |x| |a|) | << z >> |)
****** level 2  ******
$x:= z
$m:= $EmptyMode
$f:=
((((|a| # #) (|y| # #) (|x| # #) (* # # #) ...)))
   >> Apparent user error:
   cannot compile (+ (+ x a) z)

Bill Page wrote:

But this works since z is now in "scope" of the function body of bar. 

spad
)abbrev domain AAA Aaa
Aaa: with
    bar: Integer -> Integer
  == add
    (x: Integer := 4; y: Integer := 3)
    z: Integer
    bar(a: Integer): Integer == x + a + z
    z: Integer := 3 + y
spad
   Compiling FriCAS source code from file 
      /var/zope2/var/LatexWiki/6187271087318241578-25px008.spad using 
      old system compiler.
   AAA abbreviates domain Aaa 
------------------------------------------------------------------------
   initializing NRLIB AAA for Aaa 
   compiling into NRLIB AAA 
   compiling exported bar : Integer -> Integer
Time: 0.01 SEC.
(time taken in buildFunctor:  0)
;;;     ***       |Aaa| REDEFINED
;;;     ***       |Aaa| REDEFINED
Time: 0 SEC.
   Warnings: 
      [1] bar:  z has no value
   Cumulative Statistics for Constructor Aaa
      Time: 0.01 seconds
   finalizing NRLIB AAA 
   Processing Aaa for Browser database:
--->-->Aaa((bar ((Integer) (Integer)))): Not documented!!!!
--->-->Aaa(constructor): Not documented!!!!
--->-->Aaa(): Missing Description
; (DEFUN |AAA;bar;2I;1| ...) is being compiled.
;; The variable |z| is undefined.
;; The compiler will assume this variable is a global.
------------------------------------------------------------------------
   Aaa is now explicitly exposed in frame initial 
   Aaa will be automatically loaded when needed from 
      /var/zope2/var/LatexWiki/AAA.NRLIB/code

An example of Union for branches of if that yield different types: 

spad
)abbrev domain BBB Bbb
Bbb: with
    foo: Integer -> Integer
  == add
    foo(a: Integer): Integer ==
     x:Union(Integer,Float)
     if a>0 then
         x := 1
     else
         x := 2.3
     x case Integer => (x*x)::Integer
     wholePart(x*x)
spad
   Compiling FriCAS source code from file 
      /var/zope2/var/LatexWiki/3535628442473090144-25px009.spad using 
      old system compiler.
   BBB abbreviates domain Bbb 
------------------------------------------------------------------------
   initializing NRLIB BBB for Bbb 
   compiling into NRLIB BBB 
   compiling exported foo : Integer -> Integer
Time: 0.01 SEC.
(time taken in buildFunctor:  0)
;;;     ***       |Bbb| REDEFINED
;;;     ***       |Bbb| REDEFINED
Time: 0 SEC.
   Cumulative Statistics for Constructor Bbb
      Time: 0.01 seconds
   finalizing NRLIB BBB 
   Processing Bbb for Browser database:
--->-->Bbb((foo ((Integer) (Integer)))): Not documented!!!!
--->-->Bbb(constructor): Not documented!!!!
--->-->Bbb(): Missing Description
------------------------------------------------------------------------
   Bbb is now explicitly exposed in frame initial 
   Bbb will be automatically loaded when needed from 
      /var/zope2/var/LatexWiki/BBB.NRLIB/code

axiom
foo(0)
LatexWiki Image(3)
Type: PositiveInteger?
axiom
foo(1)
LatexWiki Image(4)
Type: PositiveInteger?

... --gdr, Sun, 11 May 2008 12:51:53 -0700 reply
Aldor (at least, the reference manual says) so makes variable declarations `local', unless modified by `free' or `fluid' modifiers.

Specification? --hemmecke, Tue, 13 May 2008 08:23:34 -0700 reply
Gaby, on which page of the AUG is this written?