bits-runner-builder/Syntax.md

Detailed Syntax

This documents specifies what is the allowed syntax for statements and expressions.

Symbols used

? 0 or 1 instances

* 0 or more instance

+ 1 or more instances

<TER> Terminal token, usually new line , but it can also sometimes be ,, else, or ;

<NL> New line

<ID> Identifier

<EXPR_BLOCK> Expression block

<STMT_BLOCK> Statements block

<EXPR> Expression

<STMT> Statement

Overall structure

<Statement Meta Module>
|
+ <Statement Meta Extern Function>
+ <Statemnet Variable>
+ <Statement Function>
  |
  + <Statement Block>
    |
    + <Statemnet Variable>
    + <Statement Assignment>
    + <Statement Return>
    + <Statement Loop>
      |
      + <Statement Block>...
    + <Statement Expression>
      |
      + <Expression>
      + <Expression If-Else>
        |
        + <Expression Block>...

Statement Meta Extern Function

@extern <ID> fun (: <NL>? <ID> <TYPE> (, <NL>? <ID> <TYPE>)*)? (-> <NL>? <TYPE>)?

@extern sum fun:
num1 sint32,
num2 sint32 ->
sint32

Statement Variable

<ID> <TYPE> <- <Expression>

Statement Function

<ID> fun (: <NL>? <ID> <TYPE> (, <NL>? <ID> <TYPE>)*)? (-> <NL>? <TYPE>)? <NL> <Statement Block> ;

stuff fun
;

stuff fun -> sint32
    ret 42
;

stuff fun: num1 sint32,
num2 sint32 ->
sint32
    ret num1 + num2
;

Statement Assignment

<ID> <- <EXPR> <TER>

num1 <- 5

Statement Block

( )*

Statement Expression

StatementLoop

loop [<StatementVariable> | <StatementAssignment>] (, <NL>? <Expression> (, <NL>? <Expression>)?)? <NL> <StatementBlock> ;

loop i sint32 <- 0, true, i < 10
    doStuff(i)
;

loop i sint32 <- 0,
true, i < 10
    doStuff(i)
;

loop i sint32 <- 0,
true,
i < 10
    doStuff(i)
;

loop (<ExpressionLogical> (, <NL>? <ExpressionLogical>)?)? <NL> <StatementBlock> ;

Statement Return

ret <Expression>? <NL>

ExpressionVariable:

<IDENT>

Expression If Else:

if <Expression> : <ExpressionBlock>

if num1 > 10: putchar('T')

if <Expression> : <NL> <ExpressionBlock> ;

if num1 > 10:
    num1 <- 500
    putchar('S')
;

if <Expression> : <ExpressionBlock> else <ExpressionBlock>

if num1 > 10: putchar('T') else putchar('N')

if <Expression> : <NL> <ExpressionBlock> else <NL> <ExpressionBlock> ;

if num1 > 10:
    putchar('T')
else
    putchar('N')
;

if <Expression> : <ExpressionBlock> else <NL> <ExpressionBlock> <NL> ;

if num1 > 10: putchar('T') else
    num1 <- 500
    putchar('F')
;

Expression Block

(<Statement> <NL>)* (<StatementExpression> <NL>?)? <TER>!