Loops

compiler/compiler.v

@@ -41,6 +41,11 @@ const op_print = u8(28)
 const op_println = u8(29)
 const op_assert = u8(30)
 const op_enter = u8(31)
+const op_mkarray = u8(32)
+const op_aget = u8(33)
+const op_aset = u8(34)
+const op_alen = u8(35)
+const op_apush = u8(36)
 
 // compile parses and compiles VuurRaaf source into an object file.
 pub fn compile(src string) !obj.Obj {
@@ -151,6 +156,12 @@ fn (mut g Gen) gen_stmt(st Stmt) ! {
 			g.code << op_store
 			g.code << obj.encode_i64(i64(idx))
 		}
+		.index_assign {
+			g.gen_expr(st.base)!
+			g.gen_expr(st.idx)!
+			g.gen_expr(st.expr)!
+			g.code << op_aset
+		}
 		.if_stmt {
 			else_l := g.new_label()
 			end_l := g.new_label()
@@ -186,6 +197,87 @@ fn (mut g Gen) gen_stmt(st Stmt) ! {
 			g.fixups << Fixup{ name: loop_l, off: u32(g.code.len) - 8 }
 			g.emit_label(end_l)
 		}
+		.for_range_stmt {
+			// for i in a..b / for i in a...b  →  i := a; while i <(<=) b { body; i++ }
+			var_idx := g.new_local()
+			bound_idx := g.new_local()
+			loop_l := g.new_label()
+			end_l := g.new_label()
+			g.gen_expr(st.expr)!
+			g.gen_expr(st.cond)!
+			g.emit_store(bound_idx)
+			g.emit_store(var_idx)
+			g.emit_label(loop_l)
+			g.emit_load(var_idx)
+			g.emit_load(bound_idx)
+			g.code << if st.inclusive { op_le } else { op_lt }
+			g.code << op_jz
+			g.code << obj.encode_i64(0)
+			g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
+			prev := g.locals[st.target] or { -1 }
+			g.locals[st.target] = var_idx
+			for s in st.body {
+				g.gen_stmt(s)!
+			}
+			if prev >= 0 {
+				g.locals[st.target] = prev
+			} else {
+				g.locals.delete(st.target)
+			}
+			g.emit_load(var_idx)
+			g.code << op_push_i
+			g.code << obj.encode_i64(1)
+			g.code << op_add
+			g.emit_store(var_idx)
+			g.code << op_jmp
+			g.code << obj.encode_i64(0)
+			g.fixups << Fixup{ name: loop_l, off: u32(g.code.len) - 8 }
+			g.emit_label(end_l)
+		}
+		.for_in_stmt {
+			// for x in arr  →  idx := 0; while idx < len(arr) { x := arr[idx]; body; idx++ }
+			arr_idx := g.new_local()
+			idx_idx := g.new_local()
+			elem_idx := g.new_local()
+			loop_l := g.new_label()
+			end_l := g.new_label()
+			g.gen_expr(st.expr)!
+			g.emit_store(arr_idx)
+			g.code << op_push_i
+			g.code << obj.encode_i64(0)
+			g.emit_store(idx_idx)
+			g.emit_label(loop_l)
+			g.emit_load(idx_idx)
+			g.emit_load(arr_idx)
+			g.code << op_alen
+			g.code << op_lt
+			g.code << op_jz
+			g.code << obj.encode_i64(0)
+			g.fixups << Fixup{ name: end_l, off: u32(g.code.len) - 8 }
+			g.emit_load(arr_idx)
+			g.emit_load(idx_idx)
+			g.code << op_aget
+			g.emit_store(elem_idx)
+			prev := g.locals[st.target] or { -1 }
+			g.locals[st.target] = elem_idx
+			for s in st.body {
+				g.gen_stmt(s)!
+			}
+			if prev >= 0 {
+				g.locals[st.target] = prev
+			} else {
+				g.locals.delete(st.target)
+			}
+			g.emit_load(idx_idx)
+			g.code << op_push_i
+			g.code << obj.encode_i64(1)
+			g.code << op_add
+			g.emit_store(idx_idx)
+			g.code << op_jmp
+			g.code << obj.encode_i64(0)
+			g.fixups << Fixup{ name: loop_l, off: u32(g.code.len) - 8 }
+			g.emit_label(end_l)
+		}
 		.ret_stmt {
 			if st.has_val {
 				g.gen_expr(st.expr)!
@@ -214,6 +306,18 @@ fn (mut g Gen) gen_expr(e Expr) ! {
 			g.code << obj.encode_i64(0)
 			g.relocs << obj.Reloc{ offset: u32(g.code.len) - 8, name: e.str_v, kind: 1 }
 		}
+		.array_lit {
+			for el in e.elems {
+				g.gen_expr(el)!
+			}
+			g.code << op_mkarray
+			g.code << obj.encode_i64(i64(e.elems.len))
+		}
+		.index {
+			g.gen_expr(*e.left)!
+			g.gen_expr(*e.right)!
+			g.code << op_aget
+		}
 		.bool_lit {
 			g.code << op_push_i
 			g.code << obj.encode_i64(e.int_v)
@@ -251,6 +355,23 @@ fn (mut g Gen) gen_call(e Expr) ! {
 		g.code << if e.name == 'print' { op_print } else { op_println }
 		return
 	}
+	if e.name == 'len' {
+		if e.args.len != 1 {
+			return error('len() takes exactly one argument (line ${e.line})')
+		}
+		g.gen_expr(e.args[0])!
+		g.code << op_alen
+		return
+	}
+	if e.name == 'push' {
+		if e.args.len != 2 {
+			return error('push() takes exactly two arguments (line ${e.line})')
+		}
+		g.gen_expr(e.args[0])!
+		g.gen_expr(e.args[1])!
+		g.code << op_apush
+		return
+	}
 	for a in e.args {
 		g.gen_expr(a)!
 	}
@@ -340,6 +461,24 @@ fn (mut g Gen) intern(s string) int {
 	return idx
 }
 
+fn (mut g Gen) new_local() int {
+	idx := g.local_cnt
+	g.local_cnt++
+	return idx
+}
+
+fn (mut g Gen) emit_load(idx int) {
+	g.code << op_load
+	g.code << obj.encode_i64(i64(idx))
+}
+
+fn (mut g Gen) emit_store(idx int) {
+	g.code << op_store
+	g.code << obj.encode_i64(i64(idx))
+}
+
+
+
 fn (mut g Gen) new_label() string {
 	g.next_lbl++
 	return 'L${g.next_lbl}'