stau.space
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CFG.md
+17
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CFG.md
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The following is a context-free grammar for the `iupi` language.
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```txt
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<epsilon> ::= ''
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<expr> ::= <operation> | <color>
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<language> ::= <unary operation> | <binary operation> | <color>
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<expr> ::= <binary operation> | <color>
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<unary operation> ::= <linear invert> | <value invert>
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<binary operation> ::= <add> | <multiply> | <subtract> | <divide>
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<interpolate> | <max> | <min>
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<operation> ::= <add> | <multiply> | <subtract> | <divide> | <value invert> | <linear invert> | <interpolate> | <contrast> | <max> | <min>
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<add> ::= <color> + <expr>
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<multiply> ::= <color> * <expr>
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<subtract> ::= <color> - <expr>
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<divide> ::= <color> / <expr>
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<value invert> ::= <expr> <^>
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<linear invert> ::= <expr> <|>
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<interpolate> ::= <color> <float> <expr>
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<hue shift> ::= <expr> & <integer>
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<max> ::= <color> ^ <expr>
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<min> ::= <color> ! <expr>
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<float> ::= .<digits> | <digits>.<digits>
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<integer> ::= <digits>
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<digits> ::= <digit><digits> | <epsilon>
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<digit> ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
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<hex> ::= A | B | C | D | E | F | <digit>
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<value invert> ::= <expr> <^>
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<linear invert> ::= <expr> <|>
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<color> ::= <RGB color> | <grayscale color>
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<RGB color> ::= (<integer>,<integer>,<integer>)
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<grayscale color> ::= (<integer>)
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<float> ::= .<decimals>
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<if> ::= <color> = <color> {<expr>} {<expr>}
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```
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<decimals> ::= <digit><decimals> | <epsilon>
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## Attributes
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Interesting lexeme attributes:
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<digits> ::= <digits><digit> | <epsilon>
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<digit> ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
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### Synthesization
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| Non-terminals | Synthesized attributes| Inherited attributes |
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|---------------|-----------------------|-----------------------|
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| `<colorHex>` | | `--` |
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| `<hex>` | Val | `--` |
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| `<+,>` | | `--` |
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<color> ::= (<digits>,<digits>,<digits>)
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### Base Attributes
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| Terminals | Attribute | Value |
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|-----------|-----------|-------|
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| `<digit> ::= 0` | Val | 0 |
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| `<digit> ::= 1` | Val | 1 |
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| `<digit> ::= 2` | Val | 2 |
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| `<digit> ::= 3` | Val | 3 |
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| `<digit> ::= 4` | Val | 4 |
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| `<digit> ::= 5` | Val | 5 |
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| `<digit> ::= 6` | Val | 6 |
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| `<digit> ::= 7` | Val | 7 |
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| `<digit> ::= 8` | Val | 8 |
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| `<digit> ::= 9` | Val | 9 |
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| `<hex> ::= A` | Val | 10 |
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| `<hex> ::= B` | Val | 11 |
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| `<hex> ::= C` | Val | 12 |
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| `<hex> ::= D` | Val | 13 |
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| `<hex> ::= E` | Val | 14 |
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| `<hex> ::= F` | Val | 15 |
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<epsilon> ::= ''
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```