Implemented assignments

examples/hello/hello.q

@@ -11,6 +11,7 @@ hello() {
 	address += 4194304
 	address += 1
 
+	length = 0
 	length += 50
 	length -= 20
 	length *= 10

src/build/Assignment.go

@@ -0,0 +1,38 @@
+package build
+
+import (
+	"strconv"
+
+	"git.akyoto.dev/cli/q/src/build/asm"
+	"git.akyoto.dev/cli/q/src/build/expression"
+	"git.akyoto.dev/cli/q/src/errors"
+)
+
+// CompileAssignment compiles an assignment.
+func (f *Function) CompileAssignment(expr *expression.Expression) error {
+	name := expr.Children[0].Token.Text()
+	number, _ := strconv.Atoi(expr.Children[1].Token.Text())
+	register := f.Variables[name].Register
+
+	switch expr.Token.Text() {
+	case "=":
+		f.ExpressionToRegister(expr.Children[1], register)
+
+	case "+=":
+		f.Assembler.RegisterNumber(asm.ADD, register, number)
+
+	case "-=":
+		f.Assembler.RegisterNumber(asm.SUB, register, number)
+
+	case "*=":
+		f.Assembler.RegisterNumber(asm.MUL, register, number)
+
+	case "/=":
+		f.Assembler.RegisterNumber(asm.DIV, register, number)
+
+	default:
+		return errors.New(&errors.InvalidInstruction{Instruction: expr.Token.Text()}, f.File, expr.Token.Position)
+	}
+
+	return nil
+}

src/build/Function.go

@@ -109,37 +109,32 @@ func (f *Function) CompileInstruction(line token.List) error {
 		return f.CompileVariableDefinition(expr)
 	}
 
+	if isAssignment(expr) {
+		return f.CompileAssignment(expr)
+	}
+
 	if isFunctionCall(expr) {
 		return f.CompileFunctionCall(expr)
 	}
 
-	if expr.Token.Kind == token.Operator {
-		name := expr.Children[0].Token.Text()
-		number, _ := strconv.Atoi(expr.Children[1].Token.Text())
-		register := f.Variables[name].Register
-
-		switch expr.Token.Text() {
-		case "+=":
-			f.Assembler.RegisterNumber(asm.ADD, register, number)
-			return nil
-
-		case "-=":
-			f.Assembler.RegisterNumber(asm.SUB, register, number)
-			return nil
-
-		case "*=":
-			f.Assembler.RegisterNumber(asm.MUL, register, number)
-			return nil
-
-		case "/=":
-			f.Assembler.RegisterNumber(asm.DIV, register, number)
-			return nil
-		}
-	}
-
 	return errors.New(&errors.InvalidInstruction{Instruction: expr.Token.Text()}, f.File, expr.Token.Position)
 }
 
+// isAssignment returns true if the expression is an assignment.
+func isAssignment(expr *expression.Expression) bool {
+	return expr.Token.Kind == token.Operator && expr.Token.Bytes[len(expr.Token.Bytes)-1] == '='
+}
+
+// isFunctionCall returns true if the expression is a function call.
+func isFunctionCall(expr *expression.Expression) bool {
+	return expr.Token.Kind == token.Operator && expr.Token.Text() == "λ"
+}
+
+// isVariableDefinition returns true if the expression is a variable definition.
+func isVariableDefinition(expr *expression.Expression) bool {
+	return expr.Token.Kind == token.Operator && expr.Token.Text() == ":="
+}
+
 // ExpressionToRegister moves the result of an expression into the given register.
 func (f *Function) ExpressionToRegister(root *expression.Expression, register cpu.Register) error {
 	if root.IsLeaf() {

src/build/FunctionCall.go

@@ -2,7 +2,6 @@ package build
 
 import (
 	"git.akyoto.dev/cli/q/src/build/expression"
-	"git.akyoto.dev/cli/q/src/build/token"
 )
 
 // CompileFunctionCall compiles a top-level function call.
@@ -26,8 +25,3 @@ func (f *Function) CompileFunctionCall(expr *expression.Expression) error {
 
 	return nil
 }
-
-// isFunctionCall returns true if the expression is a function call.
-func isFunctionCall(expr *expression.Expression) bool {
-	return expr.Token.Kind == token.Operator && expr.Token.Text() == "λ"
-}

src/build/VariableDefinition.go

@@ -48,8 +48,3 @@ func (f *Function) CompileVariableDefinition(expr *expression.Expression) error
 
 	return nil
 }
-
-// isVariableDefinition returns true if the expression is a variable definition.
-func isVariableDefinition(expr *expression.Expression) bool {
-	return expr.Token.Kind == token.Operator && expr.Token.Text() == ":="
-}