MiniKotlinCompiler/org.example.compiler/MiniKotlinCompiler

MiniKotlinCompiler

class MiniKotlinCompiler : MiniKotlinBaseVisitor<String>

Top-level compiler that translates a MiniKotlin parse tree into a Java source file expressed in continuation-passing style (CPS).

CPS overview

Every MiniKotlin function fun f(a: A): R is transformed into:

public static void f(A a, Continuation<R> continuation)

Instead of returning a value the function calls continuation.accept(value). The Continuation<T> interface is provided by the stdlib:

public interface Continuation<T> { void accept(T t); }

Mutable variables

Mutable var bindings are heap-boxed in a single-element array so that inner lambdas produced by the CPS transformation can close over and mutate them (Java lambdas require effectively-final captures):

var x: Int = 5  ->  Integer[] x_0 = new Integer[]{ 5 };
x = x + 1       ->  x_0[0] = x_0[0] + 1;

Responsibilities

This class handles statement-level compilation:

Function declarations and the Java main(String[]) entry point
return, if/else, while, var declaration, assignment
Standalone expression statements (e.g. println(x))

Expression-level compilation is delegated to ExpressionCompiler. Both share a SharedCounters instance so all generated names are unique.

Entry point

val compiler = MiniKotlinCompiler()
val javaSource: String = compiler.compile(programContext)

Constructors

MiniKotlinCompiler

constructor()

Functions

compile

fun compile(program: MiniKotlinParser.ProgramContext, className: String = "MiniProgram"): String

Compiles an entire MiniKotlin program to a single Java source file.

visit

open override fun visit(tree: ParseTree): String

visitAddSubExpr

open override fun visitAddSubExpr(ctx: MiniKotlinParser.AddSubExprContext): String

Visit a parse tree produced by the AddSubExpr labeled alternative in expression.

visitAndExpr

open override fun visitAndExpr(ctx: MiniKotlinParser.AndExprContext): String

Visit a parse tree produced by the AndExpr labeled alternative in expression.

visitArgumentList

open override fun visitArgumentList(ctx: MiniKotlinParser.ArgumentListContext): String

Visit a parse tree produced by argumentList.

visitBlock

open override fun visitBlock(ctx: MiniKotlinParser.BlockContext): String

Visit a parse tree produced by block.

visitBoolLiteral

open override fun visitBoolLiteral(ctx: MiniKotlinParser.BoolLiteralContext): String

Visit a parse tree produced by the BoolLiteral labeled alternative in primary.

visitChildren

open override fun visitChildren(node: RuleNode): String

visitComparisonExpr

open override fun visitComparisonExpr(ctx: MiniKotlinParser.ComparisonExprContext): String

Visit a parse tree produced by the ComparisonExpr labeled alternative in expression.

visitEqualityExpr

open override fun visitEqualityExpr(ctx: MiniKotlinParser.EqualityExprContext): String

Visit a parse tree produced by the EqualityExpr labeled alternative in expression.

visitErrorNode

open override fun visitErrorNode(node: ErrorNode): String

visitFunctionCallExpr

open override fun visitFunctionCallExpr(ctx: MiniKotlinParser.FunctionCallExprContext): String

Visit a parse tree produced by the FunctionCallExpr labeled alternative in expression.

visitFunctionDeclaration

open override fun visitFunctionDeclaration(ctx: MiniKotlinParser.FunctionDeclarationContext): String

Visit a parse tree produced by functionDeclaration.

visitIdentifierExpr

open override fun visitIdentifierExpr(ctx: MiniKotlinParser.IdentifierExprContext): String

Visit a parse tree produced by the IdentifierExpr labeled alternative in primary.

visitIfStatement

open override fun visitIfStatement(ctx: MiniKotlinParser.IfStatementContext): String

Visit a parse tree produced by ifStatement.

visitIntLiteral

open override fun visitIntLiteral(ctx: MiniKotlinParser.IntLiteralContext): String

Visit a parse tree produced by the IntLiteral labeled alternative in primary.

visitMulDivExpr

open override fun visitMulDivExpr(ctx: MiniKotlinParser.MulDivExprContext): String

Visit a parse tree produced by the MulDivExpr labeled alternative in expression.

visitNotExpr

open override fun visitNotExpr(ctx: MiniKotlinParser.NotExprContext): String

Visit a parse tree produced by the NotExpr labeled alternative in expression.

visitOrExpr

open override fun visitOrExpr(ctx: MiniKotlinParser.OrExprContext): String

Visit a parse tree produced by the OrExpr labeled alternative in expression.

visitParameter

open override fun visitParameter(ctx: MiniKotlinParser.ParameterContext): String

Visit a parse tree produced by parameter.

visitParameterList

open override fun visitParameterList(ctx: MiniKotlinParser.ParameterListContext): String

Visit a parse tree produced by parameterList.

visitParenExpr

open override fun visitParenExpr(ctx: MiniKotlinParser.ParenExprContext): String

Visit a parse tree produced by the ParenExpr labeled alternative in primary.

visitPrimaryExpr

open override fun visitPrimaryExpr(ctx: MiniKotlinParser.PrimaryExprContext): String

Visit a parse tree produced by the PrimaryExpr labeled alternative in expression.

visitProgram

open override fun visitProgram(ctx: MiniKotlinParser.ProgramContext): String

Visit a parse tree produced by program.

visitReturnStatement

open override fun visitReturnStatement(ctx: MiniKotlinParser.ReturnStatementContext): String

Visit a parse tree produced by returnStatement.

visitStatement

open override fun visitStatement(ctx: MiniKotlinParser.StatementContext): String

Visit a parse tree produced by statement.

visitStringLiteral

open override fun visitStringLiteral(ctx: MiniKotlinParser.StringLiteralContext): String

Visit a parse tree produced by the StringLiteral labeled alternative in primary.

visitTerminal

open override fun visitTerminal(node: TerminalNode): String

visitType

open override fun visitType(ctx: MiniKotlinParser.TypeContext): String

Visit a parse tree produced by type.

visitVariableAssignment

open override fun visitVariableAssignment(ctx: MiniKotlinParser.VariableAssignmentContext): String

Visit a parse tree produced by variableAssignment.

visitVariableDeclaration

open override fun visitVariableDeclaration(ctx: MiniKotlinParser.VariableDeclarationContext): String

Visit a parse tree produced by variableDeclaration.

visitWhileStatement

open override fun visitWhileStatement(ctx: MiniKotlinParser.WhileStatementContext): String

Visit a parse tree produced by whileStatement.