Start converting UBNF (ugly BNF) into BNF
This commit is contained in:
parent
6b6d084096
commit
cd18b51176
|
|
@ -7,147 +7,147 @@
|
|||
This does not follow standard BNF/EBNF syntax, I will rewrite it once I get all the definitions correct and complete.**
|
||||
|
||||
### 2.1 Input Elements and Tokens
|
||||
```
|
||||
<input character> ->
|
||||
``` bnf
|
||||
<input character> ::=
|
||||
ASCII characters but not SEOF
|
||||
|
||||
<input> ->
|
||||
<input> ::=
|
||||
<input elements> SEOF
|
||||
|
||||
<input elements> ->
|
||||
<input elements> ::=
|
||||
<input element> | <input elements> <input element>
|
||||
|
||||
<token> ->
|
||||
<token> ::=
|
||||
<variable identifier> | <keyword> | <floating-point literal>
|
||||
| <integer literal> | <string literal> | <separator> | <operator>
|
||||
```
|
||||
### 2.2 White Space
|
||||
```
|
||||
<white space> ->
|
||||
<white space> ::=
|
||||
ASCII SP character (space)
|
||||
| ASCII HT character (horizontal tab)
|
||||
| ASCII VT character (vertical tab)
|
||||
| ASCII FF character (form feed)
|
||||
| <line terminator>
|
||||
|
||||
<line terminator> ->
|
||||
<line terminator> ::=
|
||||
CR | LF | CR LF
|
||||
```
|
||||
### 2.3 Comments
|
||||
```
|
||||
<comment> ->
|
||||
<comment> ::=
|
||||
!< <opt_characters in line> <line terminator>
|
||||
|
||||
<characters in line> ->
|
||||
<characters in line> ::=
|
||||
<comment character> | <characters in line> <comment character>
|
||||
|
||||
<comment character> ->
|
||||
<comment character> ::=
|
||||
<input character> but not <line terminator>
|
||||
```
|
||||
### 2.4 Variable Identifiers
|
||||
```
|
||||
<variable identifier> ->
|
||||
<variable identifier> ::=
|
||||
<arithmetic variable identifier> | <string variable identifier>
|
||||
|
||||
<arithmetic identifier> ->
|
||||
<arithmetic identifier> ::=
|
||||
<letter> <opt_letters or digits>
|
||||
|
||||
<letters or digits> ->
|
||||
<letters or digits> ::=
|
||||
<letter or digit> | <letters or digits> <letter or digit>
|
||||
|
||||
<letter> -> one of
|
||||
<letter> ::= one of
|
||||
[a-z][A-Z]
|
||||
|
||||
<letter or digit> -> one of
|
||||
<letter or digit> ::= one of
|
||||
[a-z][A-Z][0-9]
|
||||
|
||||
<string variable identifier> ->
|
||||
<string variable identifier> ::=
|
||||
<arithmetic variable identifier>#
|
||||
```
|
||||
### 2.5 Keywords
|
||||
```
|
||||
<keyword> ->
|
||||
<keyword> ::=
|
||||
PLATYPUS | IF | THEN | ELSE | USING | REPEAT | INPUT | OUTPUT
|
||||
```
|
||||
### 2.6 Integer Literals
|
||||
```
|
||||
<integer literal> ->
|
||||
<integer literal> ::=
|
||||
<decimal integer literal> | <octal integer literal>
|
||||
|
||||
<decimal integer literal> ->
|
||||
<decimal integer literal> ::=
|
||||
0 | <non-zero digit> <opt_digits>
|
||||
|
||||
<digits> ->
|
||||
<digits> ::=
|
||||
<digit> | <digits> <digit>
|
||||
|
||||
<digit> ->
|
||||
<digit> ::=
|
||||
0 | <non-zero digit>
|
||||
|
||||
<non-zero digit> -> one of
|
||||
<non-zero digit> ::= one of
|
||||
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
|
||||
|
||||
<octal integer literal> ->
|
||||
<octal integer literal> ::=
|
||||
0 <octal digit> <octal digits>
|
||||
|
||||
<octal digit> ->
|
||||
<octal digit> ::=
|
||||
0 | 1 | 2 | 3 | 4 | 5 | 6 | 7
|
||||
|
||||
<octal digits> ->
|
||||
<octal digits> ::=
|
||||
<octal digit> | <octal digits> <octal digit>
|
||||
|
||||
```
|
||||
### 2.7 Floating-point Literals
|
||||
```
|
||||
<floating-point literal> ->
|
||||
<floating-point literal> ::=
|
||||
<decimal integer literal> . <opt_digits>
|
||||
```
|
||||
### 2.8 String Literals
|
||||
```
|
||||
<string literal> ->
|
||||
<string literal> ::=
|
||||
"<opt_string characters>"
|
||||
|
||||
<string chacters> ->
|
||||
<string chacters> ::=
|
||||
<input character> | <string characters> <input character>
|
||||
```
|
||||
### 2.9 Separators
|
||||
```
|
||||
<separator> ->
|
||||
<separator> ::=
|
||||
( | ) | { | } | , | ; | " |.
|
||||
```
|
||||
### 2.10 Operators
|
||||
```
|
||||
<operator> ->
|
||||
<operator> ::=
|
||||
<arithmetic operator> | <string concatenation operator>
|
||||
| <relational operator> | <logical operator>
|
||||
| <assignment operator>
|
||||
|
||||
<arithmetic operator> ->
|
||||
<arithmetic operator> ::=
|
||||
+ | - | * | /
|
||||
|
||||
<string concatenation operator> ->
|
||||
<string concatenation operator> ::=
|
||||
<<
|
||||
|
||||
<relational operator> ->
|
||||
<relational operator> ::=
|
||||
> | < | == | <>
|
||||
|
||||
<logical operator> ->
|
||||
<logical operator> ::=
|
||||
.AND. | .OR.
|
||||
|
||||
<assignment operator> ->
|
||||
<assignment operator> ::=
|
||||
=
|
||||
```
|
||||
## 3. The PLATYPUS Syntactic Specification
|
||||
### 3.1 PLATYPUS Program
|
||||
```
|
||||
<program> ->
|
||||
<program> ::=
|
||||
PLATYPUS {<opt_statements>} SEOF
|
||||
|
||||
<statements> ->
|
||||
<statements> ::=
|
||||
<statement> | <statements> <statement>
|
||||
```
|
||||
### 3.2 Statements
|
||||
```
|
||||
<statement> ->
|
||||
<statement> ::=
|
||||
<assignment statement>
|
||||
| <selection statement>
|
||||
| <iteration statement>
|
||||
|
|
@ -156,59 +156,59 @@ This does not follow standard BNF/EBNF syntax, I will rewrite it once I get all
|
|||
```
|
||||
### 3.3 Assignment Statement
|
||||
```
|
||||
<assignment statement> ->
|
||||
<assignment statement> ::=
|
||||
<assignment expression> ;
|
||||
|
||||
<assignment expression> ->
|
||||
<assignment expression> ::=
|
||||
<arithmetic variable identifier> = <arithmetic expression>
|
||||
| <string variable identifier> = <string expression>
|
||||
```
|
||||
#### 3.2.2 Selection Statement (`if` statement)
|
||||
```
|
||||
<selection statement> ->
|
||||
<selection statement> ::=
|
||||
IF (<conditional expression>) THEN <opt_statements>
|
||||
ELSE {<opt_statements>};
|
||||
```
|
||||
#### 3.2.3 Iteration Statement (the loop statement)
|
||||
```
|
||||
<iteration statement> ->
|
||||
<iteration statement> ::=
|
||||
USING (<assignment expression> , <conditional expression>, <assignment expression>) REPEAT { <opt_statements> };
|
||||
```
|
||||
#### 3.2.4 Input Statement
|
||||
```
|
||||
<input statement> ->
|
||||
<input statement> ::=
|
||||
INPUT (<variable list>);
|
||||
|
||||
<variable list> ->
|
||||
<variable list> ::=
|
||||
<variable identifier> | <variable list>,<variable identifier>
|
||||
```
|
||||
#### 3.2.5 Output Statement
|
||||
```
|
||||
<output statement> ->
|
||||
<output statement> ::=
|
||||
OUTPUT(<opt_variable list> | <opt_string literal>);
|
||||
```
|
||||
### 3.3 Expressions
|
||||
#### 3.3.1 Arithmetic Expressions
|
||||
```
|
||||
<arithmetic expression> ->
|
||||
<arithmetic expression> ::=
|
||||
<unary arithmetic expression>
|
||||
| <additive arithmetic expression>
|
||||
|
||||
<unary arithmetic expression> ->
|
||||
<unary arithmetic expression> ::=
|
||||
- <primary arithmetic expression>
|
||||
| + <primary arithmetic expression
|
||||
|
||||
<additive arithmetic expression> ->
|
||||
<additive arithmetic expression> ::=
|
||||
<additive arithmetic expression> + <multiplicative arithmetic expression>
|
||||
| <additive arithmetic expression> - <multiplicative arithmetic expression>
|
||||
| <multiplicative arithmetic expression>
|
||||
|
||||
<multiplicative arithmetic expression> ->
|
||||
<multiplicative arithmetic expression> ::=
|
||||
<multiplicative arithmetic expression> * <primary arithmetic expression>
|
||||
| <multiplicative arithmetic expression> / <primary arithmetic expression>
|
||||
| <primary arithmetic expression>
|
||||
|
||||
<primary arithmetic expression> ->
|
||||
<primary arithmetic expression> ::=
|
||||
<variable identifier>
|
||||
| <floating-point literal>
|
||||
| <integer literal>
|
||||
|
|
@ -216,11 +216,11 @@ This does not follow standard BNF/EBNF syntax, I will rewrite it once I get all
|
|||
```
|
||||
#### 3.3.2 String Expression
|
||||
```
|
||||
<string expression> ->
|
||||
<string expression> ::=
|
||||
<primary string expression>
|
||||
| <string expression> << <primary string expression>
|
||||
|
||||
<primary string expression> ->
|
||||
<primary string expression> ::=
|
||||
<string variable identifier>
|
||||
| <string literal>
|
||||
```
|
||||
|
|
@ -228,30 +228,30 @@ This does not follow standard BNF/EBNF syntax, I will rewrite it once I get all
|
|||
```
|
||||
// BNF from C specification adapted to PLATYPUS
|
||||
// source: https://cs.wmich.edu/~gupta/teaching/cs4850/sumII06/The%20syntax%20of%20C%20in%20Backus-Naur%20form.htm
|
||||
<conditional expression> ->
|
||||
<conditional expression> ::=
|
||||
<logical OR expression>
|
||||
|
||||
<logical OR expression> ->
|
||||
<logical OR expression> ::=
|
||||
<logical AND expression>
|
||||
| <logical OR expression> .OR. <logical AND expression>
|
||||
|
||||
<logical AND expression> ->
|
||||
<logical AND expression> ::=
|
||||
<relational expression>
|
||||
| <logical AND expression> .AND. <relational expression>
|
||||
// END BNF from C specification
|
||||
```
|
||||
#### 3.3.4 Relational Expression
|
||||
```
|
||||
<relational expression> ->
|
||||
<relational expression> ::=
|
||||
<primary a_relational expression> <relational operator> <primary a_relational expression>
|
||||
| <primary s_relational expression> <relational operator> <primary s_relational expression>
|
||||
|
||||
<primary a_relational expression> ->
|
||||
<primary a_relational expression> ::=
|
||||
<floating-point literal>
|
||||
| <integer literal>
|
||||
| <variable identifier>
|
||||
|
||||
<primary s_relational expression> ->
|
||||
<primary s_relational expression> ::=
|
||||
<string literal>
|
||||
| <string variable identifier>
|
||||
```
|
||||
Loading…
Reference in New Issue