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   1 ;
   2 ; string.sh
   3 ;
   4 ; String handling routines (control terminated)
   5 ;
   6 ; © 1994-1998 Straylight
   7 ;
   8
   9 ;----- Licensing note -------------------------------------------------------
  10 ;
  11 ; This file is part of Straylight's BASIC Assembler Supplement.
  12 ;
  13 ; BAS is free software; you can redistribute it and/or modify
  14 ; it under the terms of the GNU General Public License as published by
  15 ; the Free Software Foundation; either version 2, or (at your option)
  16 ; any later version.
  17 ;
  18 ; BAS is distributed in the hope that it will be useful,
  19 ; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ; GNU General Public License for more details.
  22 ;
  23 ; You should have received a copy of the GNU General Public License
  24 ; along with BAS.  If not, write to the Free Software Foundation,
  25 ; 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  26
  27 ;----- Overview -------------------------------------------------------------
  28 ;
  29 ; Functions provided:
  30 ;
  31 ;  str_cpy
  32 ;  str_len
  33 ;  str_cmp
  34 ;  str_icmp
  35 ;  str_subst
  36 ;  str_error
  37 ;  str_buffer
  38
  39 ; --- str_cpy ---
  40 ;
  41 ; On entry:     R0 == destination string
  42 ;               R1 == source string
  43 ;
  44 ; On exit:      R0 == pointer to terminator of destination
  45 ;
  46 ; Use:          Copies a string from one block to another.  It leaves the
  47 ;               destination pointer at the end of the string so that any
  48 ;               subsequent copies concatenate other bits on the same string.
  49 ;               Single characters can of course be appended with
  50 ;
  51 ;                       MOV     Rx,#&cc
  52 ;                       STRB    Rx,[R0],#1
  53
  54                 IMPORT  str_cpy
  55
  56 ; --- str_len ---
  57 ;
  58 ; On entry:     R0 == pointer to string
  59 ;
  60 ; On exit:      R0 == length of the string
  61 ;
  62 ; Use:          Calculates the length of a string.
  63
  64                 IMPORT  str_len
  65
  66 ; --- str_cmp ---
  67 ;
  68 ; On entry:     R0 == pointer to string A
  69 ;               R1 == pointer to string B
  70 ;
  71 ; On exit:      Flags as appropriate
  72 ;
  73 ; Use:          Case-sensitively compares two strings.  You can use the
  74 ;               normal ARM condition codes after the compare, so you can
  75 ;               treat this fairly much like a normal CMP.
  76
  77                 IMPORT  str_cmp
  78
  79 ; --- str_icmp ---
  80 ;
  81 ; On entry:     R0 == pointer to string A
  82 ;               R1 == pointer to string B
  83 ;
  84 ; On exit:      Flags as appropriate
  85 ;
  86 ; Use:          As for str_cmp above, but case-insensitive.
  87
  88                 IMPORT  str_icmp
  89
  90 ; --- str_subst ---
  91 ;
  92 ; On entry:     R0 == Pointer to skeleton
  93 ;               R1 == Pointer to output buffer
  94 ;               R2-R11 == Pointer to filler strings (optional)
  95 ;
  96 ; On exit:      R0 == Pointer to start of buffer
  97 ;               R1 == Pointer to terminating null
  98 ;
  99 ; Use:          Performs string substitution, filling in a skeleton string
 100 ;               containing placeholders with `filler' strings.  The
 101 ;               placeholders are actually rather powerful.  The syntax of
 102 ;               these is as follows:
 103 ;
 104 ;                       `%' [<type>] <digit>
 105 ;
 106 ;               (spaces are for clarity -- in fact you must not include
 107 ;               spaces in the format string.)
 108 ;
 109 ;               <digit> is any charater between `0' and `9'.  It refers to
 110 ;               registers R2-R11 (so `0' means R2, `5' is R7 etc.)  How the
 111 ;               value is interpreted is determined by <type>.
 112 ;
 113 ;               <type> is one of:
 114 ;
 115 ;               s       String.  This is the default.  The register is
 116 ;                       considered to be a pointer to an ASCII string
 117 ;                       (control terminated).
 118 ;
 119 ;               i       Integer.  The (signed) decimal representation is
 120 ;                       inserted.  Leading zeros are suppressed.
 121 ;
 122 ;               x       Hex fullword.  The hexadecimal representation of the
 123 ;                       register is inserted.  Leading zeros are included.
 124 ;
 125 ;               b       Hex byte.  The hexadecimal representation of the
 126 ;                       least significant byte is inserted.  Leading zeros
 127 ;                       are included.
 128 ;
 129 ;               c       Character.  The ASCII character corresponding to the
 130 ;                       least significant byte is inserted.
 131
 132                 IMPORT  str_subst
 133
 134 ; --- str_error ---
 135 ;
 136 ; On entry:     R0 == Pointer to skeleton
 137 ;               R2-R11 == Pointers to fillin strings
 138 ;
 139 ; On exit:      R0 == Pointer to error in buffer
 140 ;               R1 == Pointer to terminator
 141 ;
 142 ; Use:          Fills in an error skeleton (containing a 4 byte error number
 143 ;               and a control terminated skeleton string as for str_subst)
 144 ;               and returns the address of the filled in error block.  The
 145 ;               error block is stored in a buffer obtained from str_buffer.
 146 ;
 147 ;               Filler strings may be held in the scratchpad.
 148
 149                 IMPORT  str_error
 150
 151 ; ---- str_buffer ---
 152 ;
 153 ; On entry:     --
 154 ;
 155 ; On exit:      R1 == pointer to the next free buffer
 156 ;
 157 ; Use:          Returns a pointer to a 256-byte buffer.  There are at present
 158 ;               2 buffers, which are returned alternately.
 159
 160                 IMPORT  str_buffer
 161
 162 ;----- That's all, folks ----------------------------------------------------
 163
 164                 END