Oberon [3]

SCANNER oberon_scan

PARSER  oberon_pars

GLOBAL {
 # include <stdio.h>
 # include <math.h>
}

PREC LEFT  '=' '#' '<' '<=' '>' '>=' 'IN' 'IS'
     LEFT  '+' '-' 'OR'
     LEFT  '*' '/' 'DIV' 'MOD' '&'
     NONE  '~' UNARY

RULE
root 	= module  .

identdef = <
	= tok_identifier '*'
	.
	= tok_identifier
	.
> . /* identdef */

qualident = <
	= tok_identifier '.' tok_identifier
	.
	= tok_identifier
	.
> . /* qualident */

number = <
	= int_const
	.
	= real_const
	.
> . /* number */

/**********************************************************************/
/**********************************************************************/
/**********************************************************************/

expression = <
	= expression '=' expression
	.
	= expression '#' expression
	.
	= expression '<' expression
	.
	= expression '<=' expression
	.
	= expression '>' expression
	.
	= expression '>=' expression
	.
	= expression 'IN' expression
	.
	= expression 'IS' expression
	.
	= expression '+' expression
	.
	= expression '-' expression
	.
	= expression 'OR' expression
	.
	= expression '*' expression
	.
	= expression '/' expression
	.
	= expression 'DIV' expression
	.
	= expression 'MOD' expression
	.
	= expression '&' expression
	.
	= '~' expression PREC UNARY
	.
	= '+' expression PREC UNARY
	.
	= '-' expression PREC UNARY
	.
	= '(' expression ')'
	.
	= set
	.
	= designator
	.
	= procedureCall
	.
	= number
	.
	= char_const
	.
	= string_const
	.
	= 'NIL'
	.
> . /* expression */

const_expression = expression.

expression_ls = <
	= expression
	.
	= expression_ls ',' expression
	.
> . /* expression_ls */

const_expression_ls = <
	= const_expression
	.
	= const_expression_ls ',' const_expression
	.
> . /* expression_ls */

const_expression_range = <
	= const_expression
	.
	= const_expression_range '..' const_expression
	.
> . /* const_expression_range */

designator = <
	= tok_identifier
	.
	= designator '.' tok_identifier
	.
	= designator '(' expression_ls ')'
	.
	= designator '(' ')'
	.
	= designator '[' expression_ls ']'
	.
	= designator '^'
	.
> . /* designator */


set = '{' element_ls '}' .

element_ls = <
	= /* epsilon */
	.
	element_s = <
		= element
		.
		= element_s ',' element
		.
	> . /* element_s */
>. /* element_ls */

element = <
	= expression
	.
	= expression '..' expression
	.
> . /* element */

/**********************************************************************/
/**********************************************************************/
/**********************************************************************/

type = <
	= qualident
	.
	= arrayType
	.
	= recordType
	.
	= pointerType
	.
	= procedureType
	.
> . /* type */

arrayType = <
	= 'ARRAY' const_expression_ls 'OF' type
	.
> . /* arrayType */

recordType = <
	= 'RECORD' fieldListSequence 'END'
	.
	= 'RECORD' qualident fieldListSequence 'END'
	.
> . /* arrayType */

pointerType = <
	= 'POINTER' 'TO' type
	.
> . /* pointerType */

procedureType = <
	= 'PROCEDURE'
	.
	= 'PROCEDURE' formalParameters
	.
> . /* procedureType */

fieldListSequence = <
	= fieldList
	.
	= fieldList ';' fieldListSequence
	.
> . /* fieldListSequence */

fieldList = <
	= /* epsilon */
	.
	= identList ':' type
	.
>. /* fieldList */

identList = <
	= identdef
	.
	= identdef ',' identList
	.
>. /* identList */

formalParameters = <
	= '(' fpSection_ls ')'
	.
	= '(' fpSection_ls ')' ':' qualident
	.
> . /* formalParameters */

fpSection_ls = <
	= /* epsilon */
	.
	fpSection_s = <
		= fpSection
		.
		= fpSection ';' fpSection_ls
		.
	> . /* fpSection_s */
> . /* fpSection_ls */

fpSection = <
	= 'VAR' ident_ls ':' formalType
	.
	= ident_ls ':' formalType
	.
> . /* fpSection */

ident_ls = <
	= tok_identifier
	.
	= tok_identifier ',' ident_ls
	.
> . /* ident_ls */

formalType = <
	= 'ARRAY' 'OF' formalType
	.
	= qualident
	.
	= procedureType
	.
> . /* formalType */

/**********************************************************************/
/**********************************************************************/
/**********************************************************************/

statement = <
	= assignment
	.
	= procedureCall
	.
	= ifStatement
	.
	= caseStatement
	.
	= whileStatement
	.
	= repeatStatement
	.
	= loopStatement
	.
	= withStatement
	.
	= exitStatement
	.
	= returnStatement
	.
> . /* statement */

assignment = designator ':=' expression .

procedureCall = <
	= designator
	.
> . /* procedureCall */

ifStatement = <
	= 'IF' expression 'THEN' statementSequence ifStatement_ElseIf_ls 'ELSE' statementSequence 'END'
	.
	= 'IF' expression 'THEN' statementSequence ifStatement_ElseIf_ls 'END'
	.
>. /* ifStatement */

ifStatement_ElseIf_ls = <
	= /* epsilon */
	.
	= 'ELSIF' expression 'THEN' statementSequence ifStatement_ElseIf_ls
	.
>. /* ifStatement_ElseIf_ls */

caseStatement = <
	= 'CASE' expression 'OF' caseExp_ls 'ELSE' statementSequence 'END'
	.
	= 'CASE' expression 'OF' caseExp_ls 'END'
	.
> . /* caseStatement */

caseExp = <
	= /* epsilon */
	.
	= caseLabelList ':' statementSequence
	.
> . /* caseExp */

caseExp_ls = <
	= caseExp
	.
	= caseExp '|' caseExp_ls
	.
> . /* caseExp_ls */

caseLabelList = <
	= caseLabels
	.
	= caseLabels ',' caseLabelList
	.
> . /* caseLabelList */

caseLabels = const_expression_range.

whileStatement = 'WHILE' expression 'DO' statementSequence 'END' .

repeatStatement = 'REPEAT' statementSequence 'UNTIL' expression.

loopStatement = 'LOOP' statementSequence 'END' .

withStatement = 'WITH' qualident ':' qualident 'DO' statementSequence 'END' .

exitStatement = 'EXIT' .

returnStatement = <
	= 'RETURN' expression
	.
	= 'RETURN'
	.
> . /* returnStatement */

statementSequence = <
	= statement
	.
	statementSequence_ls = <
		= statement ';'
		.
		= statement ';' statementSequence
		.
	> . /* statementSequence_ls */
> . /* statementSequence */

/**********************************************************************/
/**********************************************************************/
/**********************************************************************/

constantDeclaration = identdef '=' const_expression .

typeDeclaration = identdef '=' type .

varDeclaration = ident_ls ':' type .

declarationSequence = <
	= declarationSequence_head_ls declarationSequence_foot_ls
	.
> . /* declarationSequence */

declarationSequence_head_ls = <
	= /* epsilon */
	.
	= 'CONST' ConstDecl_ls declarationSequence_head_ls
	.
	= 'TYPE' TypeDecl_ls declarationSequence_head_ls
	.
	= 'VAR' VarDecl_ls declarationSequence_head_ls
	.
> . /* declarationSequence_head_ls */

declarationSequence_foot_ls = <
	= /* epsilon */
	.
	= procedureDecl ';' declarationSequence_foot_ls
	.
	= forwardDecl ';' declarationSequence_foot_ls
	.
> . /* declarationSequence_foot_ls */

ConstDecl_ls = <
	= /* epsilon */
	.
	= constantDeclaration ';' ConstDecl_ls
	.
> . /* ConstDecl_ls */

TypeDecl_ls = <
	= /* epsilon */
	.
	= typeDeclaration ';' TypeDecl_ls
	.
> . /* TypeDecl_ls */

VarDecl_ls = <
	= /* epsilon */
	.
	= varDeclaration ';' VarDecl_ls
	.
> . /* VarDecl_ls */

/**********************************************************************/
/**********************************************************************/
/**********************************************************************/

procedureDecl = procedureHead ';' procedureBody tok_identifier .

procedureHead = <
	='PROCEDURE' '*' identdef formalParameters
	.
	='PROCEDURE' identdef formalParameters
	.
	='PROCEDURE' identdef
	.
	='PROCEDURE' '*' identdef
	.
> . /* procedureHead */

procedureBody = <
	= declarationSequence 'END'
	.
	= declarationSequence 'BEGIN' statementSequence 'END'
	.
> . /* procedureBody */

forwardDecl = <
	= 'PROCEDURE' '^' tok_identifier
	.
	= 'PROCEDURE' '^' tok_identifier '*'
	.
	= 'PROCEDURE' '^' tok_identifier formalParameters
	.
	= 'PROCEDURE' '^' tok_identifier '*' formalParameters
	.
> . /* forwardDecl */

/**********************************************************************/
/**********************************************************************/
/**********************************************************************/

import_block = <
	= /* epsilon */
	.
	= 'IMPORT' import_ls ';'
	.
> . /* import_ls */

import_ls = <
	= import
	.
	= import ',' import_ls
	.
> . /* import_ls */

import = <
	= tok_identifier
	.
	= tok_identifier ':=' tok_identifier
	.
> . /* import */

/**********************************************************************/
/**********************************************************************/
/**********************************************************************/

module = <
	= 'MODULE' tok_identifier ';' import_block declarationSequence 'BEGIN' statementSequence 'END' tok_identifier '.'
	.
	= 'MODULE' tok_identifier ';' import_block declarationSequence 'END' tok_identifier '.'
	.
> . /* module */

/**********************************************************************/
/**********************************************************************/
/**********************************************************************/


/****************************************/

/* Tokens */
int_const:      [Value: long]         {Value := 0;     } .
real_const:     [Value: double]       {Value := 0.0;   } .
char_const:     [Value: char]     	  {Value := '\0';  } .
string_const:   [Value: tStringRef]   {Value := "";    } .
tok_identifier: [Value: tStringRef]   {Value := "";    } .

/* non-terminal attributes */
MODULE attributes
PROPERTY SYN
DECLARE
END attributes