Implement while loops, Fix variable references

backend_wat.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"errors"
+	"fmt"
 	"strconv"
 	"strings"
 	"unicode"
@@ -29,7 +30,7 @@ func getPrimitiveWATType(primitive PrimitiveType) string {
 		return "i32"
 	}
 
-	panic("unhandled type")
+	panic(fmt.Sprintf("unhandled type in getPrimitiveWATType(): %s", primitive))
 }
 
 func safeASCIIIdentifier(identifier string) string {
@@ -79,7 +80,7 @@ func pushConstantNumberWAT(primitive PrimitiveType, value any) string {
 		return "f64.const " + strconv.FormatFloat(value.(float64), 'f', -1, 64) + "\n"
 	}
 
-	panic("invalid type")
+	panic(fmt.Sprintf("invalid type passed to pushConstantNumberWAT(): %s", primitive))
 }
 
 func (c *Compiler) getAddressWATType() string {
@@ -97,10 +98,10 @@ func (c *Compiler) getWATType(t Type) string {
 	case Type_Named, Type_Array:
 		return c.getAddressWATType()
 	case Type_Tuple:
-		panic("tuple type passed to getWATType()")
+		panic(fmt.Sprintf("tuple type passed to getWATType(): %s", t))
 	}
 
-	panic("type not implemented in getWATType()")
+	panic(fmt.Sprintf("type not implemented in getWATType(): %s", t))
 }
 
 func castPrimitiveWAT(from PrimitiveType, to PrimitiveType) (string, error) {
@@ -182,7 +183,7 @@ func (c *Compiler) compileAssignmentExpressionWAT(assignment AssignmentExpressio
 	switch lhs.Type {
 	case Expression_VariableReference:
 		ref := lhs.Value.(VariableReferenceExpression)
-		local := strconv.Itoa(c.CurrentBlock.Locals[ref.Variable].Index)
+		local := strconv.Itoa(getLocal(c.CurrentBlock, ref.Variable).Index)
 		return exprWAT + "local.tee $" + local + "\n", nil
 	case Expression_ArrayAccess:
 		panic("TODO") // TODO
@@ -241,7 +242,7 @@ func (c *Compiler) compileExpressionWAT(expr Expression) (string, error) {
 			cast = getTypeCast(expr.ValueType.Value.(PrimitiveType))
 		}
 
-		return "local.get $" + strconv.Itoa(c.CurrentBlock.Locals[ref.Variable].Index) + "\n" + cast, nil
+		return "local.get $" + strconv.Itoa(getLocal(c.CurrentBlock, ref.Variable).Index) + "\n" + cast, nil
 	case Expression_Binary:
 		binary := expr.Value.(BinaryExpression)
 
@@ -467,6 +468,33 @@ func (c *Compiler) compileStatementWAT(stmt Statement, block *Block) (string, er
 			wat += "end\n"
 		}
 
+		return wat, nil
+	case Statement_WhileLoop:
+		while := stmt.Value.(WhileLoopStatement)
+
+		conditionWAT, err := c.compileExpressionWAT(while.Condition)
+		if err != nil {
+			return "", err
+		}
+
+		bodyWAT, err := c.compileBlockWAT(while.Body)
+		if err != nil {
+			return "", err
+		}
+
+		wat := "block\n"
+		wat += "loop\n"
+
+		wat += conditionWAT
+		wat += "i32.eqz\n"
+		wat += "br_if 1\n"
+
+		wat += bodyWAT
+		wat += "br 0\n"
+
+		wat += "end\n"
+		wat += "end\n"
+
 		return wat, nil
 	}
 

example/test.ely

@@ -1,7 +1,8 @@
-void b(u64 x) {
-	raw(u64, 0x69u64) = x;
+u32 c(u32 n) {
+	u32 sum = 0u32;
+	while(n > 0u32) {
+		sum += n;
+		n -= 1u32;
 	}
-
-u64 a() {
-	return raw(u64, 0x69u64);
+	return sum;
 }

lexer.go

@@ -22,7 +22,7 @@ const (
 
 type Keyword uint32
 
-var Keywords []string = []string{"import", "module", "void", "return", "true", "false", "if", "else", "raw"}
+var Keywords []string = []string{"import", "module", "void", "return", "true", "false", "if", "else", "raw", "while"}
 
 const (
 	Keyword_Import Keyword = iota
@@ -34,6 +34,7 @@ const (
 	Keyword_If
 	Keyword_Else
 	Keyword_Raw
+	Keyword_While
 )
 
 type Separator uint32

parser.go

@@ -40,6 +40,7 @@ const (
 	Statement_Return
 	Statement_DeclareLocalVariable
 	Statement_If
+	Statement_WhileLoop
 )
 
 type Statement struct {
@@ -72,6 +73,11 @@ type IfStatement struct {
 	ElseBlock        *Block
 }
 
+type WhileLoopStatement struct {
+	Condition Expression
+	Body      *Block
+}
+
 type ExpressionType uint32
 
 const (
@@ -681,7 +687,7 @@ func (p *Parser) tryAssignmentExpression() (*Expression, error) {
 		return p.tryBinaryExpression()
 	}
 
-	op, err := pCopy.tryOperator(Operator_Equals)
+	op, err := pCopy.tryOperator(Operator_Equals, Operator_PlusEquals, Operator_MinusEquals, Operator_MultiplyEquals, Operator_DivideEquals, Operator_ModuloEquals)
 	if err != nil {
 		return nil, err
 	}
@@ -695,6 +701,11 @@ func (p *Parser) tryAssignmentExpression() (*Expression, error) {
 		return nil, err
 	}
 
+	if *op != Operator_Equals {
+		operation := getOperation(*op)
+		expr = &Expression{Type: Expression_Binary, Value: BinaryExpression{Left: *lhs, Right: *expr, Operation: operation}, Position: lhs.Position}
+	}
+
 	*p = pCopy
 	return &Expression{Type: Expression_Assignment, Value: AssignmentExpression{Lhs: *lhs, Value: *expr}, Position: lhs.Position}, nil
 }
@@ -885,6 +896,32 @@ func (p *Parser) expectStatement(block *Block) (*Statement, error) {
 		return &Statement{Type: Statement_If, Value: IfStatement{Condition: *cond, ConditionalBlock: conditionalBlock, ElseBlock: elseBlock}, Position: token.Position}, nil
 	}
 
+	if token.Type == Type_Keyword && token.Value.(Keyword) == Keyword_While {
+		p.nextToken()
+
+		_, err := p.expectSeparator(Separator_OpenParen)
+		if err != nil {
+			return nil, err
+		}
+
+		cond, err := p.expectExpression()
+		if err != nil {
+			return nil, err
+		}
+
+		_, err = p.expectSeparator(Separator_CloseParen)
+		if err != nil {
+			return nil, err
+		}
+
+		body, err := p.expectBlock(block)
+		if err != nil {
+			return nil, err
+		}
+
+		return &Statement{Type: Statement_WhileLoop, Value: WhileLoopStatement{Condition: *cond, Body: body}, Position: token.Position}, nil
+	}
+
 	if token.Type == Type_Separator && token.Value.(Separator) == Separator_OpenCurly {
 		block, err := p.expectBlock(block)
 		if err != nil {

validator.go

@@ -462,6 +462,21 @@ func (v *Validator) validateStatement(stmt *Statement, functionLocals *[]Local)
 		}
 
 		stmt.Value = ifS
+	case Statement_WhileLoop:
+		while := stmt.Value.(WhileLoopStatement)
+
+		errors = append(errors, v.validateExpression(&while.Condition)...)
+		errors = append(errors, v.validateBlock(while.Body, functionLocals)...)
+
+		if len(errors) != 0 {
+			return errors
+		}
+
+		if while.Condition.ValueType.Type != Type_Primitive || while.Condition.ValueType.Value.(PrimitiveType) != Primitive_Bool {
+			errors = append(errors, v.createError("condition must evaluate to boolean", while.Condition.Position))
+		}
+
+		stmt.Value = while
 	default:
 		panic("stmt not implemented")
 	}