Initial revision

[ssr] / StraySrc / Libraries / Sapphire / sail / _sh / ctrl

;
; ctrl.sh
;
; Control flow handling
;
; © 1995 Straylight
;

;----- Overview -------------------------------------------------------------
;
; Functions provided:
;
;  ctrl_let
;  ctrl_timeEq
;  ctrl_for
;  ctrl_next
;  ctrl_repeat
;  ctrl_until
;  ctrl_while
;  ctrl_endwhile
;  ctrl_gosub
;  ctrl_return
;  ctrl_if
;  ctrl_else
;  ctrl_goto
;  ctrl_case
;  ctrl_when
;  ctrl_otherwise
;  ctrl_end
;  ctrl_swap
;  ctrl_ptr
;  ctrl_ext
;  ctrl_close
;  ctrl_bput
;  ctrl_findDATA
;  ctrl_read
;  ctrl_restore
;  ctrl_sys
;  ctrl_setUpRegs
;  ctrl_resolveRegs
;  ctrl_fn
;  ctrl_equals
;  ctrl_proc
;  ctrl_endproc
;  ctrl_data
;  ctrl_def
;  ctrl_local
;  ctrl_leftS
;  ctrl_midS
;  ctrl_rightS
;  ctrl_dim
;  ctrl_store
;  ctrl_load
;  ctrl_compare

                [       :LNOT::DEF:ctrl__dfn
                GBLL    ctrl__dfn

; --- ctrl_let ---

                IMPORT  ctrl_let

; --- ctrl_timeEq ---

                IMPORT  ctrl_timeEq

; --- ctrl_for ---

                IMPORT  ctrl_for

; --- ctrl_next ---

                IMPORT  ctrl_next

; --- ctrl_repeat ---

                IMPORT  ctrl_repeat

; --- ctrl_until ---

                IMPORT  ctrl_until

; --- ctrl_while ---

                IMPORT  ctrl_while

; --- ctrl_endwhile ---

                IMPORT  ctrl_endwhile

; --- ctrl_gosub ---

                IMPORT  ctrl_gosub

; --- ctrl_return ---

                IMPORT  ctrl_return

; --- ctrl_if ---

                IMPORT  ctrl_if

; --- ctrl_else ---

                IMPORT  ctrl_else

; --- ctrl_goto ---

                IMPORT  ctrl_goto

; --- ctrl_case ---

                IMPORT  ctrl_case

; --- ctrl_when ---

                IMPORT  ctrl_when

; --- ctrl_otherwise ---

                IMPORT  ctrl_otherwise

; --- ctrl_end ---

                IMPORT  ctrl_end

; --- ctrl_swap ---

                IMPORT  ctrl_swap

; --- ctrl_ptr ---

                IMPORT  ctrl_ptr

; --- ctrl_ext ---

                IMPORT  ctrl_ext

; --- ctrl_close ---

                IMPORT  ctrl_close

; --- ctrl_bput ---

                IMPORT  ctrl_bput

; --- ctrl__findDATA ---
;
; On entry:     All the normal things
;
; On exit:      R0 == *address* in file of next DATA
;
; Use:          Sets the internal data pointer to the first DATA statement
;               fromthe current position.

                IMPORT  ctrl_findDATA

; --- ctrl_read ---

                IMPORT  ctrl_read

; --- ctrl_restore ---

                IMPORT  ctrl_restore

; --- ctrl_sys ---

                IMPORT  ctrl_sys

; --- ctrl_setUpRegs ---
;
; On entry:     R7-R10 == position info
;
; On exit:      R0-R8 set up for sys call
;               R9,R10 == rvalue of first parameter
;               On the stack:
;                 new position info, R7-R12
;                 place to stracc free
;
; Use:          Sets up all the registers as required by a SYS or SYSCALL
;               command.

                IMPORT  ctrl_setUpRegs

; --- ctrl_resolveRegs ---
;
; On entry:     R0 == pointer to register block
;
; On exit:      CS if flags were required, CC otherwise
;
; Use:          Resolves the registers returned from a SYS or SYSCALL
;               into the appropriate variables.  The code assumes that
;               we have possibly just read a TO command, and goes on
;               from there.

                IMPORT  ctrl_resolveRegs

; --- FN ---
;
; OK, maybe it shouldn't be here.  I don't really care.
;
; Hack warning: This is a hack.  We unwind express_read's stack and stuff
;               them away somewhere completely different.

                IMPORT  ctrl_fn

; --- = ---

                IMPORT  ctrl_equals

; --- PROC ---

                IMPORT  ctrl_proc

; --- ENDPROC ---

                IMPORT  ctrl_endproc

; --- DATA ---

                IMPORT  ctrl_data

; --- DEF  ---

                IMPORT  ctrl_def

; --- LOCAL ---

                IMPORT  ctrl_local

; --- ctrl_leftS ---

                IMPORT  ctrl_leftS

; --- ctrl_midS ---

                IMPORT  ctrl_midS

; --- ctrl_rightS ---

                IMPORT  ctrl_rightS

; --- ctrl_dim ---

                IMPORT  ctrl_dim

; --- ctrl_store ---
;
; On entry:     R0,R1 == lvalue to store in
;               R2,R3 == rvalue to write
;
;               If bit 31 of R1 is set, then for strings only, the old
;               string is NOT removed from the stracc. This is
;               so that variables can be restored after a procedure.
;
; On exit:      --
;
; Use:          Stores an rvalue into an lvalue.

                IMPORT  ctrl_store

; --- ctrl_load ---
;
; On entry:     R0,R1 == lvalue to read
;
; On exit:      R2,R3 == rvalue read from lvalue
;
; Use:          Loads the current value of the given lvalue.

                IMPORT  ctrl_load

; --- ctrl_compare ---
;
; On entry:     R0,R1 == thing to compare
;               R2,R3 == thing to compare the other thing with
;
; On exit:      The flags indicate the result of the comparison
;
; Use:          Compares two things.  Note that R3 contains the dominant
;               type. If it is comparing strings, the string in R0,R1
;               will be removed from stracc.

                IMPORT  ctrl_compare

                ]

;----- That's all, folks ----------------------------------------------------

                END