source_3_bnf.tex

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&& \textit{program}    &&\quad ::= &\quad && \textit{import-directive} ... \ \textit{statement} ...
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/3.1.1\#p6}{program}} \\[1mm]
&& \textit{import-directive}    &&\quad ::= &\quad && \textbf{\texttt{import}}\ \textbf{\texttt{\{}}\ \textit{import-names} \ \textbf{\texttt{\}}}\ \textbf{\texttt{from}}\  \textit{string} \ \textbf{\texttt{;}}
                                                           && \textrm{import directive} \\[1mm]
&& \textit{import-names}   && ::= &\quad &&  \epsilon\ | \  \textit{import-name} \ 
                                                   (\ \textbf{\texttt{,}} \ \textit{import-name}\ ) ...
                                                            && \textrm{import name list}   \\[1mm]
&& \textit{import-name}   && ::= &\quad &&  \textit{name}\ | \  \textit{name} \ \textbf{\texttt{as}}\ \textit{name} 
                                                            && \textrm{import name}   \\[1mm]
&& \textit{statement}    &&\quad ::= &\quad && \textbf{\texttt{const}}\  \textit{name} \ 
                                           \textbf{\texttt{=}}\  \textit{expression} \ \textbf{\texttt{;}}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.2\#p2}{constant declaration}} \\
&&                       && |   &\quad && \textit{let} \ \textbf{\texttt{;}}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/3.1.1\#p3}{variable declaration}} \\
&&                       && |   &\quad && \textbf{\texttt{function}}\  \textit{name} \ 
                                   \textbf{\texttt{(}}\  \textit{rest-names} \ \textbf{\texttt{)}}\ \textit{block} \quad
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.4\#p4}{function declaration}}\\
&&                       && |   &\quad && \textbf{\texttt{return}}\  \textit{expression} \ \textbf{\texttt{;}}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.4\#p4}{return statement}}\\
&&                       && |   &\quad && \textit{if-statement} \quad
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.3.2\#p13}{conditional statement}}\\
&&                       && |   &\quad && \textbf{\texttt{while}}\  
                                   \textbf{\texttt{(}}\  \textit{expression} \ \textbf{\texttt{)}} \
                                   \textit{block}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/4.1.2\#ex_4.7}{while loop}}\\
&&                       && |   &\quad && \textbf{\texttt{for}}\ \textbf{\texttt{(}} \ 
                                          (\ \textit{\href{https://sourceacademy.org/sicpjs/4.1.2\#ex_4.8}{expression}}_1 \ | \  \textit{\href{https://sourceacademy.org/sicpjs/4.1.2\#ex_4.9}{let}}\ ) \textbf{\texttt{;}} \\
&&                       &&     &\quad && \ \ \ \ \ \ \ \ \ \ \textit{expression}_2 \ \textbf{\texttt{;}} \\
&&                       &&     &\quad && \ \ \ \ \ \ \ \ \ \ \textit{expression}_3 \ \textbf{\texttt{)}} \ 
                                            \textit{block}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/4.1.2\#ex_4.8}{for loop}}\\
&&                       && |   &\quad && \textbf{\texttt{break}}\ \textbf{\texttt{;}}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/4.1.2\#ex_4.7}{break statement}}\\
&&                       && |   &\quad && \textbf{\texttt{continue}}\ \textbf{\texttt{;}}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/4.1.2\#ex_4.7}{continue statement}}\\
&&                       && |   &\quad &&  \textit{block} 
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.8\#p14}{block statement}}\\
&&                       && |   &\quad &&  \textit{expression} \ \textbf{\texttt{;}}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.1\#p3}{expression statement}} \\
&&                       && |   &\quad &&  \textbf{\texttt{debugger}} \ \textbf{\texttt{;}}
                                                           && \textrm{breakpoint} \\[1mm]
&& \textit{names}   && ::= &\quad &&  \epsilon\ | \  \textit{name} \ 
                                                   (\ \textbf{\texttt{,}} \ \textit{name}\ ) ...
                                                            && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.4\#p4}{name list}} \\[1mm]
&& \textit{rest-names}   && ::= &\quad &&  \epsilon\ | \  \texttt{...} \textit{name} \ |  \ \textit{name} \ 
                                           (\texttt{,}\ \textit{name}) ...\ [\texttt{, ...}\textit{name}]
                                                            && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.4\#p4}{name list} (\href{https://sourceacademy.org/sicpjs/3.4.2\#p17}{rest})} \\[1mm]
&& \textit{if-statement} && ::= &\quad &&  \textbf{\texttt{if}}\
                                   \textbf{\texttt{(}}\ \textit{expression} \ \textbf{\texttt{)}}\ 
                                   \textit{block} \\
&&                       &&     &      && [ \ \textbf{\texttt{else}}\
                                          (\ \textit{block}
                                          \ | \
                                          \textit{\href{https://sourceacademy.org/sicpjs/1.3.3\#footnote-1}{if-statement}} \ )\ ]
                                                            && \textrm{\href{https://sourceacademy.org/sicpjs/1.3.2\#p12}{conditional statement}} \\[1mm]
&& \textit{block}        && ::= &      && \textbf{\texttt{\{}}\  \textit{statement} ... \ \textbf{\texttt{\}}} \quad
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.8\#p14}{block statement}} \\[1mm]
&& \textit{let}          && ::= &\quad &&  \textbf{\texttt{let}}\  \textit{name} \ 
                                           \textbf{\texttt{=}}\  \textit{expression} 
                                                            && \textrm{\href{https://sourceacademy.org/sicpjs/3.1.1\#p3}{variable declaration}} \\[1mm]
&& \textit{assignment}   && ::= &\quad &&  \textit{name} \ 
                                           \textbf{\texttt{=}}\  \textit{expression} 
                                                            && \textrm{\href{https://sourceacademy.org/sicpjs/3.1.1\#p4}{variable assignment}} \\
&&                       && |   &\quad && \textit{expression} \textbf{\texttt{[}}
                                          \textit{expression} \textbf{\texttt{]}} \ 
                                           \textbf{\texttt{=}}\  \textit{expression} 
                                                           && \textrm{array assignment} \\[1mm]
&& \textit{expression}   && ::= &\quad &&  \textit{number}   && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.1\#p3}{primitive number expression}}\\
&&                       && |   &\quad && \textbf{\texttt{true}}\ |\ \textbf{\texttt{false}}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.6\#p1}{primitive boolean expression}}\\
&&                       && |   &\quad &&  \textit{string}   && \textrm{\href{https://sourceacademy.org/sicpjs/2.3.1}{primitive string expression}} \\
&&                       && |   &\quad && \textbf{\texttt{null}}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/2.2.1\#p1}{primitive list expression}} \\
&&                       && |   &\quad &&  \textit{name}   && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.2}{name expression}} \\
&&                       && |   &\quad &&  \textit{expression} \  \textit{binary-operator} \ 
                                            \textit{expression} \qquad
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.1\#p5}{binary operator combination}} \\
&&                       && |   &\quad &&   \textit{unary-operator} \ 
                                            \textit{expression}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.6\#p4}{unary operator combination}}\\
&&                       && |   &\quad &&  \textit{expression} \  \textit{binary-logical} \ 
                                            \textit{expression} \qquad
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.6\#p5}{logical composition}}\\
&&                       && |   &\quad &&   \textit{expression} \ 
                                            \textbf{\texttt{(}}\ \textit{spread-expressions}\
                                            \textbf{\texttt{)}}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.4\#p5}{function application}} \\
&&                       && |   &\quad &&   (\ \textit{name}\ | \
                                               \textbf{\texttt{(}}\ \textit{rest-names}\ \textbf{\texttt{)}}\
                                            )\    
                                            \texttt{\textbf{=>}}\ \textit{expression}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.3.2}{lambda expression (expr. body)}} \\
&&                       && |   &\quad &&   (\ \textit{name}\ | \
                                               \textbf{\texttt{(}}\ \textit{rest-names}\ \textbf{\texttt{)}}\
                                            )\    
                                            \texttt{\textbf{=>}}\ \textit{block}
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/2.2.4\#footnote-3}{lambda expression (block body)}} \\
&&                       && |   &\quad &&   \textit{expression} \ \textbf{\texttt{?}}\ 
                                            \textit{expression}
                                            \ \textbf{\texttt{:}}\
                                            \textit{expression}\
                                                           && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.6\#p1}{conditional expression}} \\
&&                       && |   &\quad && \textit{assignment} 
                                                           && \textrm{assignment} \\
&&                       && |   &\quad && \textit{expression} \textbf{\texttt{[}}
                                          \textit{expression} \textbf{\texttt{]}}
                                                           && \textrm{array access} \\
&&                       && |   &\quad &&   \textbf{\texttt{[}}\ 
                                            \textit{expressions}\
                                            \textbf{\texttt{]}}
                                                           && \textrm{literal array expression}\\
&&                       && |   &\quad &&  \textbf{\texttt{(}}\  \textit{expression} \ 
                                            \textbf{\texttt{)}} && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.1\#p6}{parenthesised expression}}\\[1mm]
&& \textit{binary-operator}    \ 
                        && ::= &\quad && \textbf{\texttt{+}}\ |\ \textbf{\texttt{-}}\ |\ \textbf{\texttt{*}}\ |\ \textbf{\texttt{/}}\ |\ \textbf{\texttt{\%}}\ |\ 
                                   \textbf{\texttt{===}}\ |\ \textbf{\texttt{!==}}\ \\
&&                       && |  &\quad &&  \texttt{\textbf{>}}\ |\ \texttt{\textbf{<}}\ |\ \texttt{\textbf{>=}}\ |\ \texttt{\textbf{<=}}
                                          && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.1\#p4}{binary operator}}\\[1mm]
&& \textit{unary-operator}    
                        && ::= &\quad && \textbf{\texttt{!}}\ |\ \textbf{\texttt{-}}
                        && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.6\#p4}{unary operator}}\\[1mm]          
&& \textit{binary-logical}   && ::=  &\quad &&  \textbf{\texttt{\&\&}}\ |\ \texttt{\textbf{||}}
                                          && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.6\#p5}{logical composition symbol}}\\[1mm]
&& \textit{expressions}  && ::= &\quad && \epsilon\ | \ \textit{expression}\ (
                                                               \ \textbf{\texttt{,}} \
                                                                 \textit{expression} \ 
                                                                      ) ...
                                                            && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.4\#p5}{element expressions}}\\[1mm]
&& \textit{spread-expressions}  && ::= &\quad && \epsilon\ | \ \textit{spread-expression}\ (
                                                               \ \textbf{\texttt{,}} \
                                                                 \textit{spread-expression} \ 
                                                                      ) ...\quad
                                                            && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.4\#p5}{argument expressions}}\\[1mm]
&& \textit{spread-expression}  && ::= &\quad && \textit{expression} \ |\ 
                                               \texttt{...}\ \textit{expression}
                                                            && \textrm{\href{https://sourceacademy.org/sicpjs/1.1.4\#p5}{argument expression} (\href{https://sourceacademy.org/sicpjs/3.4.2\#p17}{spread})}
\end{alignat*}