Implemented if statements

src/build/core/CompileIf.go

@@ -0,0 +1,48 @@
+package core
+
+import (
+	"fmt"
+
+	"git.akyoto.dev/cli/q/src/build/asm"
+	"git.akyoto.dev/cli/q/src/build/ast"
+)
+
+// CompileIf compiles a branch instruction.
+func (f *Function) CompileIf(branch *ast.If) error {
+	condition := branch.Condition
+	tmpRight := f.cpu.Input[1]
+	err := f.ExpressionToRegister(condition.Children[1], tmpRight)
+
+	if err != nil {
+		return err
+	}
+
+	tmpLeft := f.cpu.Input[0]
+	err = f.ExpressionToRegister(condition.Children[0], tmpLeft)
+
+	if err != nil {
+		return err
+	}
+
+	f.assembler.RegisterRegister(asm.COMPARE, tmpLeft, tmpRight)
+	elseLabel := fmt.Sprintf("%s_if_%d_else", f.Name, f.count.branch)
+
+	switch condition.Token.Text() {
+	case "==":
+		f.assembler.Label(asm.JNE, elseLabel)
+	case "!=":
+		f.assembler.Label(asm.JE, elseLabel)
+	case ">":
+		f.assembler.Label(asm.JLE, elseLabel)
+	case "<":
+		f.assembler.Label(asm.JGE, elseLabel)
+	case ">=":
+		f.assembler.Label(asm.JL, elseLabel)
+	case "<=":
+		f.assembler.Label(asm.JG, elseLabel)
+	}
+
+	defer f.assembler.Label(asm.LABEL, elseLabel)
+	f.count.branch++
+	return f.CompileAST(branch.Body)
+}

src/build/core/CompileLoop.go

@@ -3,13 +3,14 @@ package core
 import (
 	"fmt"
 
+	"git.akyoto.dev/cli/q/src/build/asm"
 	"git.akyoto.dev/cli/q/src/build/ast"
 )
 
 // CompileLoop compiles a loop instruction.
 func (f *Function) CompileLoop(loop *ast.Loop) error {
 	label := fmt.Sprintf("%s_loop_%d", f.Name, f.count.loop)
-	f.assembler.Label(label)
+	f.assembler.Label(asm.LABEL, label)
 	defer f.assembler.Jump(label)
 	f.count.loop++
 	return f.CompileAST(loop.Body)

src/build/core/Function.go

@@ -45,7 +45,7 @@ func NewFunction(name string, file *fs.File, body token.List) *Function {
 // Compile turns a function into machine code.
 func (f *Function) Compile() {
 	defer close(f.finished)
-	f.assembler.Label(f.Name)
+	f.assembler.Label(asm.LABEL, f.Name)
 	f.err = f.CompileTokens(f.Body)
 	f.assembler.Return()
 }
@@ -90,6 +90,9 @@ func (f *Function) CompileASTNode(node ast.Node) error {
 	case *ast.Return:
 		return f.CompileReturn(node)
 
+	case *ast.If:
+		return f.CompileIf(node)
+
 	case *ast.Loop:
 		return f.CompileLoop(node)
 

src/build/core/state.go

@@ -21,7 +21,8 @@ type state struct {
 
 // counter stores how often a certain statement appeared so we can generate a unique label from it.
 type counter struct {
-	loop int
+	loop   int
+	branch int
 }
 
 // PrintInstructions shows the assembly instructions.