This commit is contained in:
Valk Richard Li 2020-01-04 22:15:29 +08:00 committed by GitHub
parent 98c58c4680
commit d24e7088e3
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GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 82 additions and 24 deletions

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@ -25,6 +25,7 @@ int main()
std::cout<<">> [lexer ] turn code into tokens."<<std::endl;
std::cout<<">> [parser] turn tokens into abstract syntax tree."<<std::endl;
std::cout<<">> [ast ] check the abstract syntax tree."<<std::endl;
std::cout<<">> [run ] run code."<<std::endl;
std::cout<<">> [exit ] quit nasal interpreter."<<std::endl;
}
else if(command=="cls")

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@ -25,6 +25,8 @@ class nasal_parse
abstract_syntax_tree string_expr();
abstract_syntax_tree nil_expr();
abstract_syntax_tree var_outside_definition();
abstract_syntax_tree loop_expr();
abstract_syntax_tree choose_expr();
};
void nasal_parse::print_detail_token()
@ -99,7 +101,7 @@ void nasal_parse::push_token()
if(!checked_tokens.empty())
{
parse_token_stream.push(checked_tokens.top());
this_token=checked_token.top();
this_token=checked_tokens.top();
checked_tokens.pop();
}
else
@ -145,7 +147,7 @@ void nasal_parse::main_generate()
case __while:
case __for:
case __foreach:
case __forindex:break;
case __forindex:this->push_token();root.get_children().push_back(loop_expr());break;
case __semi:break;
default:++error;print_parse_error(error_token_in_main,this_token.line,this_token.type);
}
@ -186,6 +188,7 @@ abstract_syntax_tree nasal_parse::nil_expr()
abstract_syntax_tree nasal_parse::var_outside_definition()
{
abstract_syntax_tree definition_node;
definition_node.set_type(__definition);
this->get_token();
if(this_token.type!=__var)
{
@ -204,7 +207,28 @@ abstract_syntax_tree nasal_parse::var_outside_definition()
++error;
print_parse_error(definition_lack_id,this_token.line);
}
return definition_node;
}
abstract_syntax_tree nasal_parse::loop_expr()
{
abstract_syntax_tree loop_main_node;
loop_main_node.set_type(__loop);
this->get_token();
switch(this_token.type)
{
case __for:
case __while:
case __foreach:
case __forindex:break;
}
return loop_main_node;
}
abstract_syntax_tree nasal_parse::choose_expr()
{
abstract_syntax_tree choose_main_node;
choose_main_node.set_type(__ifelse);
return choose_main_node;
}
#endif

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@ -6,28 +6,61 @@
<number> ::= <token_number>
<string> ::= <token_string>
<nil> ::= <token_reserve_word_nil>
<id> ::= <token_identifier>
<dynamic_id> ::= <token_dynamic_id>
<vector> ::= <[> {<scalar> <,>} <]>
<hash> ::= <{> {(<id> | <string>) <:> <scalar> <,>} <}>
<scalar> ::=
<number>
| <nil>
| <string>
| <call_identifier>
| <calculation>
| <function>
| <(> <scalar> <)>
| <hash>
| <vector>
<calculation_expr> ::=
<or_expr> {<and> <or_expr>}
<or_expr> ::=
<unary_expr> {<or> <unary_expr>}
| <unary_expr> {<or> <additive_expr>}
| <additive_expr> {<or> <unary_expr>}
| <additive_expr> {<or> <additive_expr>}
<unary_expr> ::=
<-> <additive_expr>
| <!> <additive_expr>
<additive_expr> ::=
<multive_expr> {<+> <multive_expr>}
| <multive_expr> {<-> <multive_expr>}
| <multive_expr> {<~> <multive_expr>}
<multive_expr> ::=
<scalar> {<*> <scalar>}
| <scalar> {</> <scalar>}
<function> ::=
<func> [<(> <)>] <statement>
| <func> [<(> <)>] <{> {<statement> <;>} <}>
| <func> <(> {<id> <,>} {<id> <=> <scalar> <,>} {<dynamic_id>} <)> <statement>
| <func> <(> {<id> <,>} {<id> <=> <scalar> <,>} {<dynamic_id>} <)> <{> {<statement> <;>} <}>
<call_identifier> ::=
<scalar> { (<[> {<scalar> <,>} <]>) | (<[> <scalar> <:> [<scalar>] <]>) | (<.> <id>) | (<(> {<scalar> <,>} <)>) | (<(> {<id> <:> <scalar> <,>} <)>) }
| <id> { (<[> {<scalar> <,>} <]>) | (<[> <scalar> <:> [<scalar>] <]>) | (<.> <id>) | (<(> {<scalar> <,>} <)>) | (<(> {<id> <:> <scalar> <,>} <)>) }
| <func> <id>
| <func> <id> <(> <)> { (<[> {<scalar> <,>} <]>) | (<[> <scalar> <:> [<scalar>] <]>) | (<.> <id>) | (<(> {<scalar> <,>} <)>) | (<(> {<id> <:> <scalar> <,>} <)>) }
<calculation> ::=
<and_calc>
| <or_calc>
| <additive_calc>
| <multive_calc>
| <scalar>
<and_calc> ::=
<or_calc> {<and> <or_calc>}
<or_calc> ::=
<additive_calc> {<or> <additive_calc>}
<additive_calc> ::=
<multive_calc> {<+>|<->|<~> <multive_calc>}
<multive_calc> ::=
<scalar> {<*>|</> <scalar>}
<definition> ::=
<var> <id>
| <var> <id> <=> <scalar>
| <var> <(> {(<id>) | (<call_identifier>) <,>} <)> <=> <scalar>
| <(> <var> {(<id>) | (<call_identifier>) <,>} <)> <=> <scalar>
| <var> <(> {(<id>) | (<call_identifier>) <,>} <)> <=> <(> {<scalar> <,>} <)>
| <(> <var> {(<id>) | (<call_identifier>) <,>} <)> <=> <(> {<scalar> <,>} <)>
<assignment> ::=
<call_identifier> <=> <scalar>
| <(> {<call_identifier> <,>} <)> <=> <scalar>
| <(> {<call_identifier> <,>} <)> <=> <(> {<scalar> <,>} <)>
<loop_expr> ::=
<for_loop>
| <while_loop>
@ -38,13 +71,13 @@
| <for> <(> [<statement>] <;> [<scalar>] <;> <statement> <)> <{> {<statement> <;>} <}>
<while_loop> ::=
<while> <(> <scalar> <)> <statement> [<;>]
| <while> <(> <scalar> <) <{> {<statement> <;>} <}>
| <while> <(> <scalar> <)> <{> {<statement> <;>} <}>
<forindex_loop> ::=
<forindex> <(> [<statement] <;> [<scalar>] <)> <statement> [<;>]
| <forindex> <(> [<statement] <;> [<scalar>] <) <{> {<statement> <;>} <}>
| <forindex> <(> [<statement] <;> [<scalar>] <)> <{> {<statement> <;>} <}>
<foreach_loop> ::=
<foreach> <(> [<statement] <;> [<scalar>] <)> <statement> [<;>]
| <foreach> <(> [<statement] <;> [<scalar>] <) <{> {<statement> <;>} <}>
| <foreach> <(> [<statement] <;> [<scalar>] <)> <{> {<statement> <;>} <}>
<choose_expr> ::= <choose_expr_if> {<choose_expr_elsif>} [<choose_expr_else>]
<choose_expr_if> ::=
@ -57,7 +90,7 @@
| <else> <if> <(> <scalar> <)> <{> {<statement> <;>} <}>
<choose_expr_else> ::=
<else> <statement> [<;>]
| <else> {<statement> <;>} <}>
| <else> <{> {<statement> <;>} <}>
<continue_expr> ::= <continue>
<break_expr> ::= <break>