Especificação Formal
Esta especificação descreve a gramática da linguagem KriolLang usando uma forma modificada de Backus-Naur Form (BNF).
Programa
Seção intitulada “Programa”<program> ::= <statements>
<statements> ::= <statements> <statement> | <statement>
<statement> ::= <expression_statement> | <compound_statement> | <selection_statement> | <iteration_statement> | <jump_statement> | <function_declaration> | <molda_declaration> | <declaration> | <import_statement>Importação
Seção intitulada “Importação”<import_statement> ::= T_INPRISTAN <single_import><single_import> ::= T_STR_LITDeclaração de variáveis
Seção intitulada “Declaração de variáveis”<type_specifier> ::= T_TYPE_NUM | T_TYPE_NTER | T_TYPE_BOOL | T_TYPE_TEXTU | T_TYPE_PRIMITIVE | T_TYPE_IDENT
<constant> ::= T_INT_LIT | T_FLOAT_LIT | T_BOOL_LIT | T_STR_LIT | T_FSTR_LIT
<identifier> ::= T_IDENT<declarator> ::= <identifier><array_declarator>::= '[' T_INT_LIT ']' <declarator>
<declaration> ::= <type_specifier> <declarator> '=' <initializer> ';' | <type_specifier> <array_declarator> '=' <initializer> ';' | T_DIPOZ <type_specifier> <declarator> ';' | T_DIPOZ <type_specifier> <array_declarator> ';'
<initializer> ::= <expression> | <array_initializer> | <array_initializer> T_MUL T_INT_LIT
<typed_array_initializer> ::= '<' <type_specifier> '>' <array_initializer><array_initializer> ::= '[' <array_initializer_elements> ']'<array_initializer_elements>::= <value_expression> | <array_initializer_elements> ',' <value_expression><value_expression> ::= <constant_expression>Notas:
- Declarações sem inicializador são inválidas salvo se prefixadas com
dipoz. - A sintaxe de repetição
[valor] * Nrequer um literal inteiroN. - A sintaxe
<tipo>[...]cria um literal de array com tipo explícito. - Um literal
[ ... ]sem tipo explícito precisa de contexto, como uma variável ou campo de array. - Nomes de tipos de moldes declarados com
moldausamT_TYPE_IDENT, isto é, começam com letra maiúscula.
Expressões binárias
Seção intitulada “Expressões binárias”<logical_or_expression> ::= <logical_and_expression> | <logical_or_expression> T_OR <logical_and_expression>
<logical_and_expression> ::= <equality_expression> | <logical_and_expression> T_AND <equality_expression>
<equality_expression> ::= <relational_expression> | <equality_expression> T_EQ <relational_expression> | <equality_expression> T_NE <relational_expression>
<relational_expression> ::= <additive_expression> | <relational_expression> T_LT <additive_expression> | <relational_expression> T_GT <additive_expression> | <relational_expression> T_LE <additive_expression> | <relational_expression> T_GE <additive_expression>
<additive_expression> ::= <multiplicative_expression> | <additive_expression> T_PLUS <multiplicative_expression> | <additive_expression> T_MINUS <multiplicative_expression>
<multiplicative_expression> ::= <unary_expression> | <multiplicative_expression> T_MUL <primary_expression> | <multiplicative_expression> T_DIV <primary_expression>Outras expressões
Seção intitulada “Outras expressões”<expression> ::= <assignment_expression><constant_expression> ::= <logical_or_expression>
<unary_expression> ::= <primary_expression> | T_NOT <unary_expression> | T_MINUS <unary_expression>
<primary_expression> ::= <postfix_expression>
<postfix_expression> ::= <primary_atom> | <postfix_expression> '(' <argument_list> ')' | <postfix_expression> '(' ')' | <postfix_expression> '[' <expression> ']' | <postfix_expression> '.' T_IDENT | <postfix_expression> '::' T_IDENT
<primary_atom> ::= <identifier> | <constant> | <record_literal> | <typed_array_initializer> | '(' <expression> ')'
<record_literal> ::= T_TYPE_IDENT '::' '{' <record_field_initializers> '}' | T_TYPE_IDENT '::' '{' '}'
<record_field_initializers> ::= T_IDENT ':' <initializer> | <record_field_initializers> ',' T_IDENT ':' <initializer>
<assignment_expression> ::= <constant_expression> | <primary_expression> <assignment_operator> <assignment_expression>
<assignment_operator> ::= '=' | '+=' | '-=' | '*=' | '/='Moldes (molda)
Seção intitulada “Moldes (molda)”<molda_declaration> ::= T_MOLDA T_TYPE_IDENT '{' <molda_field_declarations> '}'
<molda_field_declarations> ::= <molda_field_declaration> | <molda_field_declarations> <molda_field_declaration>
<molda_field_declaration> ::= <type_specifier> <declarator> ';' | <type_specifier> <array_declarator> ';'Notas:
- Um molde declarado com
moldadeve declarar pelo menos um campo. - Atribuição a campos usa a mesma regra de assignment de outros alvos
atribuíveis, como
valor.campo = expr. - Campos podem ser arrays de tamanho fixo.
- Acesso e atribuição podem encadear campos e índices, como
pessoa.enderesus[0].rua = "medio".
Funções
Seção intitulada “Funções”<function_declaration> ::= T_FN <declarator> '(' <parameter_optional_list> ')' <type_specifier> <compound_statement> | T_FN <declarator> '(' <parameter_optional_list> ')' <compound_statement>
<parameter_optional_list> ::= <parameter_list> | λ
<parameter_list> ::= <parameter_declaration> | <parameter_list> ',' <parameter_declaration>
<parameter_declaration> ::= <type_specifier> <declarator>
<argument_list> ::= <argument_list> ',' <expression> | <expression>
<function_call> ::= <identifier> '(' <argument_list> ')' | <identifier> '(' ')'
<expression_statement>::= <expression> ';' | ';'<compound_statement> ::= '{' <statements> '}' | '{' '}'Seleção
Seção intitulada “Seleção”<selection_statement> ::= T_SI <expression> <compound_statement> | T_SI <expression> <compound_statement> T_SINON <else_then>
<else_then> ::= <compound_statement> | <selection_statement>Iteração
Seção intitulada “Iteração”<iteration_statement> ::= T_NKUANTU <expression> <compound_statement> | T_PA <expression> ';' <expression> ';' <expression> <compound_statement><jump_statement> ::= T_PARA ';' | T_KONTINUA ';' | T_DIVOLVI <expression> ';' | T_DIVOLVI ';' | T_SAI '(' <expression> ')' ';' | T_KONFIRMA '(' <expression> ')' ';'Referências
Seção intitulada “Referências”Este projeto é possível graças a (mas não apenas) essas referências:
- https://github.com/lsegal/my_toy_compiler
- https://llvm.org/docs/tutorial/MyFirstLanguageFrontend/index.html
- https://github.com/xkbeyer/liquid
- https://kuree.gitbooks.io/the-go-programming-language-report/content/18/text.html
- https://cs.wmich.edu/~gupta/teaching/cs4850/sumII06/The%20syntax%20of%20C%20in%20Backus-Naur%20form.htm
- S. Sarda, Mayur Pandey, TotalBoox, and TBX, LLVM Essentials. Packt Publishing, 2015.
- C. Donnelly and R. Stallman, Bison: the Yacc-comp. parser generator. 2015
- L. Segal, “Writing Your Own Toy Compiler Using Flex, Bison and LLVM,” Sep. 18, 2009. http://gnuu.org/2009/09/18/writing-your-own-toy-compiler/ (accessed Jun., 2022).