SIMULA 67(ID:301/sim053)

  1 <program> :: {<block prefix>}<block> | {<block prefix>}<compound statement>
  2  <block prefix> ::= <class identifier>{(<actual paremeter list>)}
  3   <block> ::= <block head>;<compound tail>
  4    <block head> ::= <block head>;<declaration> | BEGIN <declaration>

  5 <declaration> ::= <type declaration> | <array declaration> | <switch declaration> | <procedure declaration> | <class declaration> | <external declaration>
  6  <type declaration> ::= <type><identifier list>
  7   <type> ::= BOOLEAN | CHARACTER | INTEGER | REAL | REF(<class declaration>) | TEXT
  8   <identifier list> ::= {<identifier list>,}<identifier>
  9  <array declaration> ::= {<type>} ARRAY <array list>
 10   <array list> ::={<array list>,} <array segment>
 11    <array segment> ::= <identifier list>[<bound pair list>]
 12     <bound pair list> ::= {<bound pair list>,}<arithmetic expression>:<arithmetic expression>
 13  <switch declaration> ::= SWITCH <switch identifier> := <switch list>
 14   <switch identifier> ::= <identifier>
 15   <switch list> ::= {<switch list>,}<designational expression>
 16  <procedure declaration> ::= {<type>} PROCEDURE <procedure heading>;<proceduere body>
 17   <procedure heading> ::= <procedure identifier>{<formal parameter part>;{<mode part>;}<specification part>}
 18    <formal parameter part> ::= (<identifier list>)
 19    <mode part> ::= {<value part>;}<name part> | {<name part>;}<value part>
 20     <value part> ::= VALUE <identifier list>
 21     <name part> ::= NAME <identifier list>
 22    <specification part> ::= {<specification part>;}<specifier><identifier list>
 23     <specifier> ::= {<type>} ARRAY | LABEL | {<virtual part>;}<identifier list>
 24   <procedure body> ::= <statement>
 25  <class declaration> :: {<prefix>} CLASS <class heding>;{<virtual part>;}<class body>
 26   <prefix> ::= <class identifier>
 27   <class heading> ::= <class identifier>{<formal paremeter part>;{<value part>;}<specification part>}
 28    <class identifier> ::= <identifier>
 29   <virtual part> ::= VIRTUAL: <virtual specification part>
 30    <virtual specification part> ::= {<virtual specification part>;}<virtual specifier><identifier list>
 31     <virtual specifier> ::= LABEL | {<type>} PROCEDURE | SWITCH
 32   <class body> ::= <split body> | <statement>
 33    <split body> :: <initial part> INNER; <compound tail>
 34     <initial part> ::= BEGIN | <block head>; | <initial part><statement>
 35  <external declaration> ::= EXTERNAL {<type>} PROCEDURE <external list> | EXTERNAL CLASS <external list>
 36   <external list> ::= {<external list>,}<external item>
 37    <external item> ::= <external identifier> | <identifier> = <external identifier>

 38 <compound statement> ::= BEGIN <compound tail>
 39  <compound tail> ::= END | <statement>;<compound tail>
 40   <statement> ::= <label list><statement> | <conditional statement> | <connection statement> | <repetition statement> | <unconditional statement>
 41    <label list> ::= {<label list>}<label>:
 42     <label> ::= <identifier>
 43    <conditional statement> ::= <if clause><connection statement> | <if clause><repetition statement> | <if clause><unconditional statement>{ELSE <statement>}
 44     <if clause> ::= IF <Boolean expression> THEN
 45    <connection statement> ::= INSPECT <object expression><connection part>{OTHERWISE <statement>}
 46     <connection part> ::= DO <statement> | <selective part>
 47      <selective part> ::= {<selective part>} WHEN <class identifier> DO <statement>
 48    <repetition statement> ::=<for statement> | <while statement>
 49     <for statement> ::= FOR <variable> :- <reference list> DO <statement> | FOR <variable> := <value list> DO <statement>
 50      <reference list> ::= {<reference list>,}<reference expression> {WHILE <Boolean expression>}
 51      <value list> ::= {<value list>,}<value list element>
 52       <value list element> ::= <value expression>{WHILE <Boolean expression>} | <arithmetic expression> STEP <arithmetic expression> UNTIL <arithmetic expression>
 53     <while statement> ::= WHILE <Boolean expression> DO <statement>
 54    <unconditional statement> ::= <basic statement> | {<block prefix>}<block> | {<block prefix>}<compound statement>
 55     <basic statement> ::= <activation statement> | <assignment statement> | <dummy statement> | <goto statement> | <object generator> | <procedure satement>
 56      <activation statement> ::=<activator><object expression>{<scheduling part>}
 57       <activator> ::= ACTIVATE | REACTIVATE
 58       <scheduling part> ::= AT <arithmetic expression>{PRIOR} | DELAY <arithmetic expression> {PRIOR} | BEFORE <object expression> | AFTER <object expression>
 59      <assignment statement> ::= <reference assignment> | <value assignment>
 60       <reference assignment> ::= <reference left part> :- <reference right part>
 61        <reference left part> ::= <variable> | <procedure identifiere>
 62        <reference right part> ::= <reference expression> | <reference assignment>
 63       <value assignment> ::= <value left part> := <value right part>
 64        <value left part> ::= <variable> | <procedure identifier> | <simple text expression>
 65        <value right part> ::= <value expression> | <value assignment>
 66      <dummy statement> ::= <empty>
 67      <goto statement> ::= GOTO <designational expression>
 68      <object generator> ::= NEW <class identifier> {(<actual parameter list>)}
 69      <procedure statement> ::= {<simple reference expression>,}<procedure identifier>{(<actual parameter list>)}
 70       <simple reference expression> ::= <simple object expression> | <simple text expression>
 71       <actual parameter list> ::= {<actual parameter list>,}<actual parameter>
 72        <actual parameter> ::= <expression> | <array identifier> | <procedure identifier> | <switch identifier>
 73         <array identifier> ::= {<simple object expression>.}<identifier>
 74         <procedure identifier> ::= {<simple reference expression>.}<identifier>

 75 <expression> ::= <designational expression> | <reference expression> | <value expression>
 76  <designational expression> ::= <simple designational expression> | <if clause> <simple designational expression> ELSE <designational expression>
 77   <simple designational expression> ::= (<designational expression>) | <labal> | <switch designator>
 78    <switch designator> ::= <switch identifier>[<arithmetic expression>]
 79  <reference expression> ::= <object expression> | <text expression>
 80   <object expression> ::= <simple object expression> | <if clause><simple object expression> ELSE <object expression>
 81    <simple object expression> ::= (<object expression>) | NONE | <function designator> | <local object> | <object generator> | <qualified object> | <variable>
 82     <fuction designator> ::= <procedure identifier> {(<actual parameter list>)}
 83     <local object> ::= THIS <class identifier>
 84     <qualified object> ::= <simple object expression> QUA <class identifier>
 85   <text expression> ::= <simple text expression> | <if clause><simple text expression> ELSE <text expression>
 86    <simple text expression> ::= (<text expression>) | NOTEXT | <function designator> | <variable>
 87   <value expression> ::= <arithmetic expression> | <Boolean expression> | <character expression> | <text value expression>
 88    <simple arithmetic expression> ::= <simple arithmetic expression> | <if clause><simple arithmetic expression> ELSE <arithmetic expression>
 89     <simple arithmetic expression> ::= {{<simple arithmetic expression>}<adding operator>}<arithmetic term>
 90      <adding operator> ::= + | -
 91      <arithmetic term> ::= {<arithmetic term><multiplying operator>}<arithmetic factor>
 92       <multiplying operator> ::= x | / | ÷
 93       <arithmetic factor> ::= {<arithmetic factor>^}<arithmetic primary>
 94        <arithmetic primary> ::= (<arithmetic expression>) | <function designator> | <unsigned number> | <variable>
 95         <unsigned number> ::= <decimal number> {<exponent part>} | <exponent part>
 96          <decimal number> ::= <unsigned integer>{<decimal fraction>} | <decimal fraction>
 97           <unsigned integer> ::= {<unsigned integer>}<digit>
 98           <decimal fraction> ::= .<unsigned integer>
 99          <exponent part> ::= \10{<adding operator>}<unsigned integer>
100    <Boolean expression> ::= <simple Boolean> | <if clause><simple Boolean> ELSE <Boolean expression>
101     <simple Boolean> ::= {<simple Boolean> \equ} <implication>
102      <implication> ::= {<implication> \imp}<Boolean term>
103       <Boolean term> ::= {<Boolean term> \or}<Boolean factor>
104        <Boolean factor> ::= {<Boolean factor> \and}{\not}<Boolean primary>
105         <Boolean primary> ::= (<Boolean expression>} | <logical value> | <function designator> | <relation> | <variable>
106          <logical value> ::= TRUE | FALSE
107          <relation> ::= <qualification relation> | <reference relation> | <value expression>
108           <qualification relation> ::= <simple object expression><qualification tester><class identifier>
109            <qualification tester> ::= IS | IN
110           <reference releation> ::= <object reference relation> | <text reference relation>
111            <object reference relation> ::= <simple object expression> <reference comparator><simple object expression>
112             <reference comparator> ::= == | =/=
113            <text reference relation> ::= <simple text expression><refernce comparator><simple text expression>
114           <value relation> ::= <arithmetic relation> | <character relation> | <text value relation>
115            <arithmetic relation> ::= <simple arithmetic expression><relational operator><simple arithmetic expression>
116             <relational operator> ::= < | ¾ | = | „ | > | ‚
117            <chracter relation> ::= <simple character expression><relational operator><simple character expression>
118            <text value relation> ::= <simple text value><relational operator><simple text value>
119    <character expression> ::= <simple character expression> | <if clause><simple character expression> ELSE <character expression>
120     <simple character expression> ::= (<character expression> | <character constant> | <function designator> | <variable>
121     <character constant> ::= ′<any basic symbol>′
122   <text value expression> ::= <simple text value> | <if clause><simple text value> ′ELSE′ <text value expression>
123    <simle text value> ::= <simple text expression> | <text constant>
124     <text constant> ::= ′<any sequence of basic symbols>′

125 <variable> ::= <simple object expression>.<variable> | <simple variable> | <subscripted variable>
126  <simple variable> ::= <identifier>
127   <identifier ::= {<identifier>}<letter> | <identifier><digit>
128    <letter> ::= A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z
129    <digit> ::= 0|1|2|3|4|5|6|7|8|9|0
130  <subscripted variable> ::= <array identifier>[<subscript list>]
131   <subscript list> ::= {<subscript list>,}<arithmetic expression>

# special signs:

÷    ... division - a line between two dots aligned verticaly  (92)
^    ... power - an up-arrow  (93)
\10  ... power of ten - a lowered "10"  (99)
\equ ... logical equation - three strokes aligned verticaly  (101)
\imp ... logical implication - a "U" turned counter-clockwise  (102)
\or  ... logical or - a sign like a "v"  (103)
\and ... logical and - like a flipped "v"  (104)
\not ... logical not "¬" - like a flipped and conter-clockwise turned "L" (104)