Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Improve printing of nested expressions #5918

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Improve printing of nested expressions #5918

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
80 changes: 38 additions & 42 deletions src/exprs.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -40,6 +40,37 @@
#include "hpc/aobjects.h"
#endif

struct ExprsState {

/****************************************************************************
**
*V PrintPrecedence . . . . . . . . . . . . . . . . current precedence level
**
** 'PrintPrecedence' contains the current precedence level, i.e., an integer
** indicating the binding power of the currently printed operator. If one of
** the operands is an operation that has lower binding power it is printed
** in parenthesis. If the right operand has the same binding power it is put
** in parenthesis, since all the operations are left associative.
** Precedence: 14: ^; 12: mod,/,*; 10: -,+; 8: in,=; 6: not; 4: and; 2: or.
** This sometimes puts in superfluous parenthesis: 2 * f( (3 + 4) ), since it
** doesn't know that a function call adds automatically parenthesis.
*/
UInt PrintPrecedence;

UInt OldPrintPrecedence;

};

static ModuleStateOffset ExprsStateOffset = -1;

extern inline struct ExprsState * ExprsState(void)
{
return (struct ExprsState *)StateSlotsAtOffset(ExprsStateOffset);
}

#define PrintPrecedence ExprsState()->PrintPrecedence
#define OldPrintPrecedence ExprsState()->OldPrintPrecedence

/****************************************************************************
**
*V EvalExprFuncs[<type>] . . . . . evaluator for expressions of type <type>
Expand Down Expand Up @@ -1224,7 +1255,10 @@ void InstallPrintExprFunc(unsigned int pos, PrintExprFunc f)
*/
void PrintExpr(Expr expr)
{
UInt oldPrec = OldPrintPrecedence = PrintPrecedence;
PrintPrecedence = 0;
(*PrintExprFuncs[TNUM_EXPR(expr)])(expr);
PrintPrecedence = oldPrec;
}


Expand All @@ -1244,34 +1278,6 @@ static void PrintUnknownExpr(Expr expr)
}


struct ExprsState {

/****************************************************************************
**
*V PrintPrecedence . . . . . . . . . . . . . . . . current precedence level
**
** 'PrintPrecedence' contains the current precedence level, i.e., an integer
** indicating the binding power of the currently printed operator. If one of
** the operands is an operation that has lower binding power it is printed
** in parenthesis. If the right operand has the same binding power it is put
** in parenthesis, since all the operations are left associative.
** Precedence: 14: ^; 12: mod,/,*; 10: -,+; 8: in,=; 6: not; 4: and; 2: or.
** This sometimes puts in superfluous parenthesis: 2 * f( (3 + 4) ), since it
** doesn't know that a function call adds automatically parenthesis.
*/
UInt PrintPrecedence;

};

static ModuleStateOffset ExprsStateOffset = -1;

extern inline struct ExprsState * ExprsState(void)
{
return (struct ExprsState *)StateSlotsAtOffset(ExprsStateOffset);
}

#define PrintPrecedence ExprsState()->PrintPrecedence

/****************************************************************************
**
*F PrintNot(<expr>) . . . . . . . . . . . . . print a boolean not operator
Expand All @@ -1280,9 +1286,7 @@ extern inline struct ExprsState * ExprsState(void)
*/
static void PrintNot(Expr expr)
{
UInt oldPrec;

oldPrec = PrintPrecedence;
UInt oldPrec = OldPrintPrecedence;
PrintPrecedence = 6;

// if necessary print the opening parenthesis
Expand All @@ -1296,8 +1300,6 @@ static void PrintNot(Expr expr)
// if necessary print the closing parenthesis
if ( oldPrec >= PrintPrecedence ) Pr("%2<)", 0, 0);
else Pr("%2<", 0, 0);

PrintPrecedence = oldPrec;
}


Expand All @@ -1310,9 +1312,7 @@ static void PrintNot(Expr expr)
*/
static void PrintAInv(Expr expr)
{
UInt oldPrec;

oldPrec = PrintPrecedence;
UInt oldPrec = OldPrintPrecedence;
PrintPrecedence = 11;

// if necessary print the opening parenthesis
Expand All @@ -1332,11 +1332,10 @@ static void PrintAInv(Expr expr)

static void PrintBinop(Expr expr)
{
UInt oldPrec; // old precedence level
const Char * op; // operand
BOOL printEqPrec = FALSE; // Print() at equal precedence
// remember the current precedence level
oldPrec = PrintPrecedence;

UInt oldPrec = OldPrintPrecedence;

// select the new precedence level
switch ( TNUM_EXPR(expr) ) {
Expand Down Expand Up @@ -1396,9 +1395,6 @@ static void PrintBinop(Expr expr)
(oldPrec == PrintPrecedence && printEqPrec))
Pr("%2<)", 0, 0);
else Pr("%2<", 0, 0);

// restore the old precedence level
PrintPrecedence = oldPrec;
}


Expand Down
20 changes: 19 additions & 1 deletion tst/testinstall/kernel/exprs.tst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -59,7 +59,25 @@ function ( x )
end
gap> Display( x -> 2 * f( 3 + 4 ));
function ( x )
return 2 * f( (3 + 4) );
return 2 * f( 3 + 4 );
end
gap> Display({}->1^(1,2,2*(4-1)));
function ( )
return 1 ^ (1,2,2 * (4 - 1));
end
gap> Display({}->1-[1-1]);
function ( )
return 1 - [ 1 - 1 ];
end
gap> Display(function ( )
> return 1 - function ( )
> return 1 - 1;
> end( );
> end);
function ( )
return 1 - function ( )
return 1 - 1;
end( );
end

# PrintTildeExpr, EvalTildeExpr
Expand Down
Loading