Squirrel grammar #237

mingodad · 2021-05-20T16:08:15Z

I'm testing this interesting parser generator https://ssw.jku.at/Research/Projects/Coco/ and as exercise I'm building a Squirrel/SquiLu grammar with it.

As usual any feedback is welcome !

This is the initial CocoR grammar just in case someone else want to try (edited with my latest):


#include "Scanner.nut"

COMPILER Squirrel

CHARACTERS
	letter    = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_".
	oct        = '0'..'7'.
	digit     = '0'..'9'.
	nzdigit    = '1'..'9'.
	cr        = '\r'.
	lf        = '\n'.
	tab       = '\t'.
	stringCh  = ANY - '"' - '\\' - cr - lf.
	charCh    = ANY - '\'' - '\\' - cr - lf.
	printable = '\u0020' .. '\u007e'.
	hex        = digit + 'a'..'f' + 'A'..'F'.

TOKENS
	TK_IDENTIFIER     = letter { letter | digit }.

	TK_FLOAT = ( '.' digit {digit} [('e'|'E')  ['+'|'-'] digit {digit}]
						 | digit {digit} '.' {digit} [('e'|'E')  ['+'|'-'] digit {digit}]
						 | digit {digit} ('e'|'E')  ['+'|'-'] digit {digit}
						 )
						 .

	TK_INTEGER   = ( /*nz*/ digit {digit}
						 //| '0' {oct}
						 | ("0x"|"0X") hex {hex}
						 )
						 .

	TK_STRING_LITERAL    = ['@'] '"' {stringCh |  '\\' (printable | ['\r'] '\n')} '"'
			| "'" { charCh | '\\' (printable | ['\r'] '\n')} "'"
			.

	badString = '"' {stringCh | '\\' printable} (cr | lf)
			| "'" {charCh | '\\' printable } (cr | lf)
			.

	TK_AND = "&&".
	TK_ATTR_CLOSE = "/>".
	TK_ATTR_OPEN = "</".
	TK_BASE = "base".
	TK_BIT_AND_EQ = "&=".
	TK_BIT_OR_EQ = "|=".
	TK_BIT_SHIFT_LEFT_EQ = "<<=".
	TK_BIT_SHIFT_RIGHT_EQ = ">>=".
	TK_BIT_XOR_EQ = "^=".
	TK_BREAK = "break".
	TK_CASE = "case".
	TK_CATCH = "catch".
	TK_CLASS = "class".
	TK_CLONE = "clone".
	TK_CONST = "const".
	TK_CONTINUE = "continue".
	TK_CONSTRUCTOR = "constructor".
	TK_DEFAULT = "default".
	TK_DELETE = "delete".
	TK_DIVEQ = "/=".
	TK_DO = "do".
	TK_DOUBLE_COLON = "::".
	TK_EQ = "==".
	TK_ELSE = "else".
	TK_ENUM = "enum".
	TK_FALSE = "false".
	TK___FILE__ = "__FILE__".
	TK_FOREACH = "foreach".
	TK_FOR = "for".
	TK_FUNCTION = "function".
	TK___FUNCTION__ = "__FUNCTION__".
	TK_GOTO = "goto".
	TK_GE = ">=".
	TK_IF = "if".
	TK_IN = "in".
	TK_INSTANCEOF = "instanceof".
	TK_LE = "<=".
	TK___LINE__ = "__LINE__".
	TK_LOCAL = "local".
	TK_MINUSEQ = "-=".
	TK_MINUSMINUS = "--".
	TK_MODEQ = "%=".
	TK_MULEQ = "*=".
	TK_NE = "!=".
	TK_NEWSLOT = "<-".
	TK_NULL = "null".
	TK_OR = "||".
	TK_PLUSEQ = "+=".
	TK_PLUSPLUS = "++".
	TK_RAWCALL = "rawcall".
	TK_RESUME = "resume".
	TK_RETURN = "return".
	TK_SHIFTL = ">>".
	TK_SHIFTR = "<<".
	TK_STATIC = "static".
	TK_SWITCH = "switch".
	TK_THIS = "this".
	TK_THROW = "throw".
	TK_3WAYSCMP = "<=>".
	TK_TRUE = "true".
	TK_TRY = "try".
	TK_TYPEOF = "typeof".
	TK_USHIFTR = ">>>".
	TK_VARPARAMS = "...".
	TK_WHILE = "while".
	TK_YIELD = "yield".




COMMENTS FROM "/*" TO "*/" NESTED
COMMENTS FROM "//" TO lf

IGNORE cr + lf + tab

PRODUCTIONS

Squirrel = {Statement}
	.

Statement =
	(
	IfStatement
	| WhileStatement
	| DoWhileStatement
	| ForStatement
	| ForEachStatement
	| SwitchStatement
	| LocalDeclStatement
	| ReturnStatement
	| YeldStatement
	| BreakStatement
	| ContinueStatement
	| FunctionStatement
	| ClassStatement
	| EnumStatement
	| Statements
	| TryCatchStatement
	| ThrowStatement
	| ConstStatement
	| CommaExpr
	) [';']
	.

IfStatement = TK_IF '(' CommaExpr ')' IfBlock [TK_ELSE IfBlock]
	.

IfBlock = Statement
	.

WhileStatement = TK_WHILE '(' CommaExpr ')' Statement
	.

DoWhileStatement = TK_DO Statement TK_WHILE '(' CommaExpr ')'
	.

ForStatement = TK_FOR '(' [LocalDeclStatement | CommaExpr] ';' [CommaExpr] ';' [CommaExpr] ')' Statement
	.

ForEachStatement = TK_FOREACH '(' TK_IDENTIFIER [',' TK_IDENTIFIER] TK_IN Expression ')' Statement
	.

SwitchStatement = TK_SWITCH '(' CommaExpr ')'  '{' {CaseStatement} [TK_DEFAULT ':' Statement] '}'
	.

CaseStatement = TK_CASE ExpressionScalar ':' [Statement]
	.

LocalDeclStatement = TK_LOCAL
	(
	TK_FUNCTION TK_IDENTIFIER CreateFunction
	|  AssignExpr {',' AssignExpr}
	)
	.

AssignExpr = TK_IDENTIFIER ['=' Expression]
	.

ReturnStatement = TK_RETURN [CommaExpr]
	.

YeldStatement = TK_YIELD [CommaExpr]
	.

BreakStatement = TK_BREAK
	.

ContinueStatement = TK_CONTINUE
	.

FunctionStatement = TK_FUNCTION TK_IDENTIFIER {"::" (TK_IDENTIFIER | TK_CONSTRUCTOR)} CreateFunction
	.

CreateFunction =  FunctionParams Statement
	.

CreateLambda =  FunctionParams Expression
	.

FunctionParams =  '(' [TK_VARPARAMS | OneFunctionParam {',' OneFunctionParam}] ')'
	.

OneFunctionParam =  TK_IDENTIFIER ['=' Expression]
	.

ClassStatement =
	TK_CLASS PrefixedExpr
	(';' | ClassExp)
	.

ClassExp = ["extends" Expression]
		[TK_ATTR_OPEN {ParseTable} TK_ATTR_CLOSE]
		'{' {ParseClass} '}'
	.

ParseClass = ParseTableOrClass [';']
	.

ParseTable = ParseTableOrClass [',']
	.

ParseTableOrClass =
	([TK_STATIC] TK_FUNCTION TK_IDENTIFIER | TK_CONSTRUCTOR) CreateFunction
	| '[' CommaExpr ']' '=' Expression
	| TK_STRING_LITERAL ':' Expression
	| TK_IDENTIFIER '=' Expression
	.

EnumStatement = TK_ENUM TK_IDENTIFIER '{' EnumItem {',' EnumItem} '}'
	.

EnumItem = TK_IDENTIFIER ['=' ExpectScalar]
	.

Statements = '{' {Statement} '}'
	.

TryCatchStatement = TK_TRY Statement TK_CATCH '(' TK_IDENTIFIER ')' Statement
	.

ThrowStatement = TK_THROW CommaExpr
	.

ConstStatement = TK_CONST (TK_IDENTIFIER '=' ExpectScalar)
	.

ExpectScalar = (['-'] (TK_INTEGER | TK_FLOAT)) | TK_STRING_LITERAL | TK_TRUE | TK_FALSE
	.

CommaExpr = Expression {',' Expression}
	.

Expression =
	LogicalOrExp [
		('=' | TK_NEWSLOT | TK_MINUSEQ | TK_PLUSEQ | TK_MULEQ | TK_DIVEQ | TK_MODEQ) Expression
		| '?' Expression ':' Expression
	]
	.

LogicalOrExp = LogicalAndExp {TK_OR LogicalOrExp}
	.

LogicalAndExp = BitwiseOrExp {TK_AND LogicalAndExp}
	.

BitwiseOrExp = BitwiseXorExp {'|' BitwiseXorExp}
	.

BitwiseXorExp = BitwiseAndExp {'^' BitwiseAndExp}
	.

BitwiseAndExp = EqExp {'&' EqExp}
	.

EqExp = CompExp {(TK_EQ | TK_NE | TK_3WAYSCMP) CompExp}
	.

CompExp = ShiftExp {('>' | '<' | TK_GE | TK_LE | TK_IN | TK_INSTANCEOF) ShiftExp}
	.

ShiftExp = PlusExp {(TK_USHIFTR | TK_SHIFTL | TK_SHIFTR) PlusExp}
	.

PlusExp = MultExp {('+' | '-') MultExp}
	.

MultExp = PrefixedExpr {('*' | '/' | '%') PrefixedExpr}
	.

PrefixedExpr = Factor
	{
		'.' (TK_IDENTIFIER | TK_CONSTRUCTOR)
		| '[' Expression ']'
		| (TK_MINUSMINUS | TK_PLUSPLUS)
		| FunctionCallArgs
	}
	.

Factor =
	TK_STRING_LITERAL
	| TK_BASE
	| TK_IDENTIFIER
	| TK_CONSTRUCTOR
	| TK_THIS
	| TK_DOUBLE_COLON PrefixedExpr
	| TK_NULL
	| TK_INTEGER
	| TK_FLOAT
	| TK_TRUE
	| TK_FALSE
	| '[' [Expression {[','] Expression}] ']'
	| '{' {ParseTable} '}'
	| TK_FUNCTION CreateFunction
	|  FunctionExp
	| TK_CLASS ClassExp
	| UnaryOP
	| TK_RAWCALL FunctionCallArgs
	| PrefixIncDec
	| DeleteExpr
	| '(' CommaExpr ')'
	| TK___LINE__
	| TK___FILE__
	.

FunctionExp = '@' CreateLambda
	.

UnaryOP =
	(
	'-' //(TK_INTEGER | TK_FLOAT)
	| '~' //TK_INTEGER
	| '!'
	| TK_TYPEOF
	| TK_RESUME
	| TK_CLONE
	) PrefixedExpr
	.

FunctionCallArgs = '(' [Expression {',' Expression}] ')'
	.

PrefixIncDec = (TK_MINUSMINUS | TK_PLUSPLUS) PrefixedExpr
	.

DeleteExpr =
	TK_DELETE PrefixedExpr
	.

ExpressionScalar =
	TK_INTEGER
	| TK_FLOAT
	| TK_STRING_LITERAL
	.

END Squirrel .

And here is the Squirrel EBNF accepted by https://www.bottlecaps.de/rr/ui to create railroad diagrams, copy the grammar bellow and paste on the Edit Grammar tab then switch to the View Diagram tab to view the railroad diagram.

//"/*" "*/" "//" lf cr  '+' lf  '+' tab
Squirrel ::=  ( Statement  )*
Statement ::=  ( IfStatement  | WhileStatement  | DoWhileStatement  | ForStatement  | ForEachStatement  | SwitchStatement  | LocalDeclStatement  | ReturnStatement  | YeldStatement  | BreakStatement  | ContinueStatement  | FunctionStatement  | ClassStatement  | EnumStatement  | Statements  | TryCatchStatement  | ThrowStatement  | ConstStatement  | CommaExpr  )  ( ';'  )?
IfStatement ::= TK_IF '(' CommaExpr ')' IfBlock  ( TK_ELSE IfBlock  )?
IfBlock ::= Statement
WhileStatement ::= TK_WHILE '(' CommaExpr ')' Statement
DoWhileStatement ::= TK_DO Statement TK_WHILE '(' CommaExpr ')'
ForStatement ::= TK_FOR '('  ( LocalDeclStatement  | CommaExpr  )? ';'  ( CommaExpr  )? ';'  ( CommaExpr  )? ')' Statement
ForEachStatement ::= TK_FOREACH '(' TK_IDENTIFIER  ( ',' TK_IDENTIFIER  )? TK_IN Expression ')' Statement
SwitchStatement ::= TK_SWITCH '(' CommaExpr ')' '{'  ( CaseStatement  )*  ( TK_DEFAULT ':' Statement  )? '}'
CaseStatement ::= TK_CASE ExpressionScalar ':'  ( Statement  )?
LocalDeclStatement ::= TK_LOCAL  ( TK_FUNCTION TK_IDENTIFIER CreateFunction  | AssignExpr  ( ',' AssignExpr  )*  )
AssignExpr ::= TK_IDENTIFIER  ( '=' Expression  )?
ReturnStatement ::= TK_RETURN  ( CommaExpr  )?
YeldStatement ::= TK_YIELD  ( CommaExpr  )?
BreakStatement ::= TK_BREAK
ContinueStatement ::= TK_CONTINUE
FunctionStatement ::= TK_FUNCTION TK_IDENTIFIER  ( "::"  ( TK_IDENTIFIER  | TK_CONSTRUCTOR  )  )* CreateFunction
CreateFunction ::= FunctionParams Statement
CreateLambda ::= FunctionParams Expression
FunctionParams ::= '('  ( TK_VARPARAMS  | OneFunctionParam  ( ',' OneFunctionParam  )*  )? ')'
OneFunctionParam ::= TK_IDENTIFIER  ( '=' Expression  )?
ClassStatement ::= TK_CLASS PrefixedExpr  ( ';'  | ClassExp  )
ClassExp ::=  ( "extends" Expression  )?  ( TK_ATTR_OPEN  ( ParseTable  )* TK_ATTR_CLOSE  )? '{'  ( ParseClass  )* '}'
ParseClass ::= ParseTableOrClass  ( ';'  )?
ParseTable ::= ParseTableOrClass  ( ','  )?
ParseTableOrClass ::=  (  ( TK_STATIC  )? TK_FUNCTION TK_IDENTIFIER  | TK_CONSTRUCTOR  ) CreateFunction  | '[' CommaExpr ']' '=' Expression  | TK_STRING_LITERAL ':' Expression  | TK_IDENTIFIER '=' Expression
EnumStatement ::= TK_ENUM TK_IDENTIFIER '{' EnumItem  ( ',' EnumItem  )* '}'
EnumItem ::= TK_IDENTIFIER  ( '=' ExpectScalar  )?
Statements ::= '{'  ( Statement  )* '}'
TryCatchStatement ::= TK_TRY Statement TK_CATCH '(' TK_IDENTIFIER ')' Statement
ThrowStatement ::= TK_THROW CommaExpr
ConstStatement ::= TK_CONST  ( TK_IDENTIFIER '=' ExpectScalar  )
ExpectScalar ::=  (  ( '-'  )?  ( TK_INTEGER  | TK_FLOAT  )  )  | TK_STRING_LITERAL  | TK_TRUE  | TK_FALSE
CommaExpr ::= Expression  ( ',' Expression  )*
Expression ::= LogicalOrExp  (  ( '='  | TK_NEWSLOT  | TK_MINUSEQ  | TK_PLUSEQ  | TK_MULEQ  | TK_DIVEQ  | TK_MODEQ  ) Expression  | '?' Expression ':' Expression  )?
LogicalOrExp ::= LogicalAndExp  ( TK_OR LogicalOrExp  )*
LogicalAndExp ::= BitwiseOrExp  ( TK_AND LogicalAndExp  )*
BitwiseOrExp ::= BitwiseXorExp  ( '|' BitwiseXorExp  )*
BitwiseXorExp ::= BitwiseAndExp  ( '^' BitwiseAndExp  )*
BitwiseAndExp ::= EqExp  ( '&' EqExp  )*
EqExp ::= CompExp  (  ( TK_EQ  | TK_NE  | TK_3WAYSCMP  ) CompExp  )*
CompExp ::= ShiftExp  (  ( '>'  | '<'  | TK_GE  | TK_LE  | TK_IN  | TK_INSTANCEOF  ) ShiftExp  )*
ShiftExp ::= PlusExp  (  ( TK_USHIFTR  | TK_SHIFTL  | TK_SHIFTR  ) PlusExp  )*
PlusExp ::= MultExp  (  ( '+'  | '-'  ) MultExp  )*
MultExp ::= PrefixedExpr  (  ( '*'  | '/'  | '%'  ) PrefixedExpr  )*
PrefixedExpr ::= Factor  ( '.'  ( TK_IDENTIFIER  | TK_CONSTRUCTOR  )  | '[' Expression ']'  |  ( TK_MINUSMINUS  | TK_PLUSPLUS  )  | FunctionCallArgs  )*
Factor ::= TK_STRING_LITERAL  | TK_BASE  | TK_IDENTIFIER  | TK_CONSTRUCTOR  | TK_THIS  | TK_DOUBLE_COLON PrefixedExpr  | TK_NULL  | TK_INTEGER  | TK_FLOAT  | TK_TRUE  | TK_FALSE  | '['  ( Expression  (  ( ','  )? Expression  )*  )? ']'  | '{'  ( ParseTable  )* '}'  | TK_FUNCTION CreateFunction  | FunctionExp  | TK_CLASS ClassExp  | UnaryOP  | TK_RAWCALL FunctionCallArgs  | PrefixIncDec  | DeleteExpr  | '(' CommaExpr ')'  | TK___LINE__  | TK___FILE__
FunctionExp ::= '@' CreateLambda
UnaryOP ::=  ( '-'  | '~'  | '!'  | TK_TYPEOF  | TK_RESUME  | TK_CLONE  ) PrefixedExpr
FunctionCallArgs ::= '('  ( Expression  ( ',' Expression  )*  )? ')'
PrefixIncDec ::=  ( TK_MINUSMINUS  | TK_PLUSPLUS  ) PrefixedExpr
DeleteExpr ::= TK_DELETE PrefixedExpr
ExpressionScalar ::= TK_INTEGER  | TK_FLOAT  | TK_STRING_LITERAL


letter ::= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_"
oct ::= '0'  .. '7'
digit ::= '0'  .. '9'
nzdigit ::= '1'  .. '9'
cr ::= '\r'
lf ::= '\n'
tab ::= '\t'
stringCh ::= ANY  '-' '"'  '-' '\'  '-' cr  '-' lf
charCh ::= ANY  '-' "'"  '-' '\'  '-' cr  '-' lf
printable ::= '\u0020'  .. '\u007e'
hex ::= digit  '+' 'a'  .. 'f'  '+' 'A'  .. 'F'
TK_IDENTIFIER  ::= letter  ( letter  | digit  )*
TK_FLOAT  ::=  ( '.' digit  ( digit  )*  (  ( 'e'  | 'E'  )  ( '+'  | '-'  )? digit  ( digit  )*  )?  | digit  ( digit  )* '.'  ( digit  )*  (  ( 'e'  | 'E'  )  ( '+'  | '-'  )? digit  ( digit  )*  )?  | digit  ( digit  )*  ( 'e'  | 'E'  )  ( '+'  | '-'  )? digit  ( digit  )*  )
TK_INTEGER  ::=  ( digit  ( digit  )*  |  ( "0x"  | "0X"  ) hex  ( hex  )*  )
TK_STRING_LITERAL  ::=  ( '@'  )? '"'  ( stringCh  | '\'  ( printable  |  ( '\r'  )? '\n'  )  )* '"'  | "'"  ( charCh  | '\'  ( printable  |  ( '\r'  )? '\n'  )  )* "'"
badString  ::= '"'  ( stringCh  | '\' printable  )*  ( cr  | lf  )  | "'"  ( charCh  | '\' printable  )*  ( cr  | lf  )
TK_AND  ::= "&&"
TK_ATTR_CLOSE  ::= "/>"
TK_ATTR_OPEN  ::= "</"
TK_BASE  ::= "base"
TK_BIT_AND_EQ  ::= "&="
TK_BIT_OR_EQ  ::= "|="
TK_BIT_SHIFT_LEFT_EQ  ::= "<<="
TK_BIT_SHIFT_RIGHT_EQ  ::= ">>="
TK_BIT_XOR_EQ  ::= "^="
TK_BREAK  ::= "break"
TK_CASE  ::= "case"
TK_CATCH  ::= "catch"
TK_CLASS  ::= "class"
TK_CLONE  ::= "clone"
TK_CONST  ::= "const"
TK_CONTINUE  ::= "continue"
TK_CONSTRUCTOR  ::= "constructor"
TK_DEFAULT  ::= "default"
TK_DELETE  ::= "delete"
TK_DIVEQ  ::= "/="
TK_DO  ::= "do"
TK_DOUBLE_COLON  ::= "::"
TK_EQ  ::= "=="
TK_ELSE  ::= "else"
TK_ENUM  ::= "enum"
TK_FALSE  ::= "false"
TK___FILE__  ::= "__FILE__"
TK_FOREACH  ::= "foreach"
TK_FOR  ::= "for"
TK_FUNCTION  ::= "function"
TK___FUNCTION__  ::= "__FUNCTION__"
TK_GOTO  ::= "goto"
TK_GE  ::= ">="
TK_IF  ::= "if"
TK_IN  ::= "in"
TK_INSTANCEOF  ::= "instanceof"
TK_LE  ::= "<="
TK___LINE__  ::= "__LINE__"
TK_LOCAL  ::= "local"
TK_MINUSEQ  ::= "-="
TK_MINUSMINUS  ::= "--"
TK_MODEQ  ::= "%="
TK_MULEQ  ::= "*="
TK_NE  ::= "!="
TK_NEWSLOT  ::= "<-"
TK_NULL  ::= "null"
TK_OR  ::= "||"
TK_PLUSEQ  ::= "+="
TK_PLUSPLUS  ::= "++"
TK_RAWCALL  ::= "rawcall"
TK_RESUME  ::= "resume"
TK_RETURN  ::= "return"
TK_SHIFTL  ::= ">>"
TK_SHIFTR  ::= "<<"
TK_STATIC  ::= "static"
TK_SWITCH  ::= "switch"
TK_THIS  ::= "this"
TK_THROW  ::= "throw"
TK_3WAYSCMP  ::= "<=>"
TK_TRUE  ::= "true"
TK_TRY  ::= "try"
TK_TYPEOF  ::= "typeof"
TK_USHIFTR  ::= ">>>"
TK_VARPARAMS  ::= "..."
TK_WHILE  ::= "while"
TK_YIELD  ::= "yield"

The text was updated successfully, but these errors were encountered:

mingodad · 2021-05-21T13:36:15Z

Looking through the compiler code it seems that there is a mistake here:

    void BitwiseOrExp()
    {
        BitwiseXorExp();
        for(;;) if(_token == _SC('|'))
        {BIN_EXP(_OP_BITW, &SQCompiler::BitwiseXorExp,BW_OR); ///!!!!<<< should be BitwiseOrExp ?
        }else return;
    }

mingodad · 2021-05-21T13:40:54Z

Or else the previous ones :

    void LogicalAndExp()
    {
        BitwiseOrExp();
        for(;;) switch(_token) {
        case TK_AND: {
            SQInteger first_exp = _fs->PopTarget();
            SQInteger trg = _fs->PushTarget();
            _fs->AddInstruction(_OP_AND, trg, 0, first_exp, 0);
            SQInteger jpos = _fs->GetCurrentPos();
            if(trg != first_exp) _fs->AddInstruction(_OP_MOVE, trg, first_exp);
            Lex(); INVOKE_EXP(&SQCompiler::LogicalAndExp); ///!!!<<< here we have full recursion could be BitwiseOrExp ?
            _fs->SnoozeOpt();
            SQInteger second_exp = _fs->PopTarget();
            if(trg != second_exp) _fs->AddInstruction(_OP_MOVE, trg, second_exp);
            _fs->SnoozeOpt();
            _fs->SetInstructionParam(jpos, 1, (_fs->GetCurrentPos() - jpos));
            _es.etype = EXPR;
            break;
            }

        default:
            return;
        }
    }

mingodad · 2021-05-21T13:43:00Z

My bad they are calling different functions to generate distinct code !

mingodad · 2021-05-21T14:10:36Z

It seems that the for loops here are meaningless:

@@ -469,11 +470,11 @@ public:
         _es.etype = EXPR;
     }
     void LogicalOrExp()
     {
         LogicalAndExp();
-        for(;;) if(_token == TK_OR) {
+        if(_token == TK_OR) {
             SQInteger first_exp = _fs->PopTarget();
             SQInteger trg = _fs->PushTarget();
             _fs->AddInstruction(_OP_OR, trg, 0, first_exp, 0);
             SQInteger jpos = _fs->GetCurrentPos();
             if(trg != first_exp) _fs->AddInstruction(_OP_MOVE, trg, first_exp);
@@ -482,18 +483,16 @@ public:
             SQInteger second_exp = _fs->PopTarget();
             if(trg != second_exp) _fs->AddInstruction(_OP_MOVE, trg, second_exp);
             _fs->SnoozeOpt();
             _fs->SetInstructionParam(jpos, 1, (_fs->GetCurrentPos() - jpos));
             _es.etype = EXPR;
-            break;
-        }else return;
+        }
     }
     void LogicalAndExp()
     {
         BitwiseOrExp();
-        for(;;) switch(_token) {
-        case TK_AND: {
+        if(_token == TK_AND) {
             SQInteger first_exp = _fs->PopTarget();
             SQInteger trg = _fs->PushTarget();
             _fs->AddInstruction(_OP_AND, trg, 0, first_exp, 0);
             SQInteger jpos = _fs->GetCurrentPos();
             if(trg != first_exp) _fs->AddInstruction(_OP_MOVE, trg, first_exp);
@@ -502,15 +501,10 @@ public:
             SQInteger second_exp = _fs->PopTarget();
             if(trg != second_exp) _fs->AddInstruction(_OP_MOVE, trg, second_exp);
             _fs->SnoozeOpt();
             _fs->SetInstructionParam(jpos, 1, (_fs->GetCurrentPos() - jpos));
             _es.etype = EXPR;
-            break;
-            }
-
-        default:
-            return;
         }
     }

mingodad · 2021-05-21T14:32:31Z

Following the code I discovered that in literal arrays the comma separator is optional, didn't knew this before.
Is this intended ?

local b = [1 2, 3 4];
print(b.len()); //Output -> 4

albertodemichelis · 2021-05-24T05:25:01Z

Yes, it was intended. In retrospect, I don't think it was a good decision but it really hasn't created any issue in my experience. FYI, this is also valid for function call parameters.

mingodad · 2021-05-25T08:59:34Z

Thank you for reply an clarify it !

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Squirrel grammar #237

Squirrel grammar #237

mingodad commented May 20, 2021 •

edited

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albertodemichelis commented May 24, 2021

mingodad commented May 25, 2021

Squirrel grammar #237

Squirrel grammar #237

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mingodad commented May 20, 2021 • edited Loading

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mingodad commented May 25, 2021

mingodad commented May 20, 2021 •

edited

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