diff options
| -rw-r--r-- | eval.c | 15 | ||||
| -rw-r--r-- | txr.1 | 49 |
2 files changed, 59 insertions, 5 deletions
@@ -73,7 +73,8 @@ val op_table, pm_table; val dyn_env; val eval_error_s; -val dwim_s, progn_s, prog1_s, let_s, let_star_s, lambda_s, call_s, dvbind_s; +val dwim_s, progn_s, prog1_s, prog2_s; +val let_s, let_star_s, lambda_s, call_s, dvbind_s; val sys_catch_s, handler_bind_s, cond_s, if_s, iflet_s, when_s, usr_var_s; val defvar_s, defvarl_s, defparm_s, defparml_s, defun_s, defmacro_s, macro_s; val tree_case_s, tree_bind_s, mac_param_bind_s; @@ -4145,6 +4146,16 @@ static val me_case(val form, val menv) cons(cond_s, condpairs), nao); } +static val me_prog2(val form, val menv) +{ + val arg1 = cadr(form); + + (void) menv; + + return list(progn_s, arg1, + cons(prog1_s, cddr(form)), nao); +} + static val me_tb(val form, val menv) { val opsym = pop(&form); @@ -6271,6 +6282,7 @@ void eval_init(void) dwim_s = intern(lit("dwim"), user_package); progn_s = intern(lit("progn"), user_package); prog1_s = intern(lit("prog1"), user_package); + prog2_s = intern(lit("prog2"), user_package); let_s = intern(lit("let"), user_package); let_star_s = intern(lit("let*"), user_package); lambda_s = intern(lit("lambda"), user_package); @@ -6484,6 +6496,7 @@ void eval_init(void) reg_mac(caseq_star_s, func_n2(me_case)); reg_mac(caseql_star_s, func_n2(me_case)); reg_mac(casequal_star_s, func_n2(me_case)); + reg_mac(prog2_s, func_n2(me_prog2)); reg_mac(intern(lit("tb"), user_package), func_n2(me_tb)); reg_mac(intern(lit("tc"), user_package), func_n2(me_tc)); reg_mac(intern(lit("ignerr"), user_package), func_n2(me_ignerr)); @@ -15085,16 +15085,20 @@ share any portion of the environment at any level of nesting. .desc The .code progn -operator evaluates forms in order, and returns the value -of the last form. The return value of the form +operator evaluates each +.meta form +in in left-to-right order, and returns the value +of the last form. The value of the form .code (progn) is .codn nil . The .code prog1 -operator evaluates forms in order, and returns the value -of the first form. The return value of the form +operator evaluates each +.meta form +in left-to-right order, and returns the value +of the first form. The value of the form .code (prog1) is .codn nil . @@ -15106,6 +15110,43 @@ of a body of forms, the value of the last of which is returned. These operators are said to feature an implicit .codn progn . +.TP* "Dialect Note:" +In ANSI Common Lisp, +.code prog1 +requires at least one argument. + +.coNP Macro @ prog2 +.synb +.mets (prog2 << form *) +.syne +.desc +The +.code prog2 +evaluates each +.meta form +in left-to-right order. The value is that of the second form, if present, +otherwise it is +.codn nil . + +The form +.code "(prog2 1 2 3)" +yields +.codn 2 . +The value of +.code "(prog2 1 2)" +is also +.codn 2 ; +.code "(prog2 1)" +and +.code "(prog2)" +yield +.codn nil . + +.TP* "Dialect Note:" +In ANSI Common Lisp, +.code prog2 +requires at least two arguments. + .coNP Operator @ cond .synb .mets (cond >> {( test << form *)}*) |