Critical fixes

compiler/check.v

@@ -631,7 +631,10 @@ fn builtin_result_type(name string) TypeInfo {
 		'sb_len' { TypeInfo{ kind: .int_t } }
 		'spawn' { TypeInfo{ kind: .int_t } }
 		'spawn_join' { TypeInfo{ kind: .unknown } }
-		'cwd', 'json_pretty' { TypeInfo{ kind: .string_t } }
+		'cwd', 'json_pretty', 'read_line', 'input' { TypeInfo{ kind: .string_t } }
+		'flag_val' { TypeInfo{ kind: .string_t } }
+		'flag_has' { TypeInfo{ kind: .int_t } }
+		'flag_positional' { TypeInfo{ kind: .array_t } }
 		'build_is_dir' { TypeInfo{ kind: .int_t } }
 		// build-module builtins (.vrmm)
 		'build_compile', 'build_assemble', 'build_link', 'build_exec', 'build_base',

compiler/codegen.v

@@ -1040,6 +1040,13 @@ fn builtin_spec(name string) (int, int) {
 		// concurrency
 		'spawn' { native_spawn, 1 }
 		'spawn_join' { native_spawn_join, 1 }
+		// interactive input
+		'read_line' { native_read_line, 0 }
+		'input' { native_input, 1 }
+		// getopt-style flag parsing
+		'flag_val' { native_flag_val, 1 }
+		'flag_has' { native_flag_has, 1 }
+		'flag_positional' { native_flag_positional, 0 }
 		'build_is_dir' { native_build_is_dir, 1 }
 		'cwd' { native_cwd, 0 }
 		'json_pretty' { native_json_pretty, 1 }
@@ -1301,7 +1308,7 @@ fn (mut g Gen) expr_type(e Expr) string {
 			'build_dir', 'build_join', 'build_root' { 'string' }
 			'json_encode', 'format', 'replace', 'pad', 'pad_left', 'repeat', 'sb_new', 'sb_add', 'sb_str' { 'string' }
 			'sb_len' { 'int' }
-			'cwd', 'json_pretty' { 'string' }
+			'cwd', 'json_pretty', 'read_line', 'input' { 'string' }
 			else { '' }
 		}
 	}

compiler/opcodes.v

@@ -182,3 +182,12 @@ const native_sb_len = 192
 // concurrency: spawn/join threads
 const native_spawn = 193
 const native_spawn_join = 194
+
+// interactive input: read a line from stdin
+const native_read_line = 195
+const native_input = 196
+
+// getopt-style flag parsing over args()
+const native_flag_val = 197
+const native_flag_has = 198
+const native_flag_positional = 199