plEarlz.h

00001 /*
00002 <Copyright Header>
00003 Copyright (c) 2012 Jordan "Earlz" Earls  <http://lastyearswishes.com>
00004 All rights reserved.
00005 
00006 Redistribution and use in source and binary forms, with or without
00007 modification, are permitted provided that the following conditions
00008 are met:
00009 
00010 1. Redistributions of source code must retain the above copyright
00011    notice, this list of conditions and the following disclaimer.
00012 2. Redistributions in binary form must reproduce the above copyright
00013    notice, this list of conditions and the following disclaimer in the
00014    documentation and/or other materials provided with the distribution.
00015 3. The name of the author may not be used to endorse or promote products
00016    derived from this software without specific prior written permission.
00017    
00018 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
00019 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
00020 AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
00021 THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00022 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
00023 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
00024 OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
00025 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
00026 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
00027 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00028 
00029 This file is part of the MbedConsole project
00030 */
00031 
00032 #ifndef PLEARLZ_H
00033 #define PLEARLZ_H
00034 
00035 #define MAXSTACK 64
00036 #define MAXTEMPSTACK 64
00037 #define MAXLINELENGTH 128
00038 #define DICTIONARYSTEP 4 //how much memory to reserve when doing a reallocation for resizing
00039 #define CODEBLOCKSTEP 16
00040 
00041 enum ErrorType
00042 {
00043     None,
00044     StackOverflow,
00045     StackUnderflow
00046 };
00047 
00048 //arguments are in the bytecode, not the stack! But, things like Add has no arguments and uses the stack
00049 //pointers are assumed 32-bit?
00050 enum Opcode
00051 {
00052     BranchTrue, //argument is 16 bit vaddress
00053     BranchFalse, //argument is 16bit vaddress
00054     Branch,
00055     PushTemp, //pops from stack and pushes onto the temporary stack
00056     PopTemp, //pushes onto stack from temporary stack
00057     Push, //argument is 32bit number
00058     Drop, //trashes top value on stack
00059     Call, //call. argument is WORD entry pointer in dictionary
00060     CallInt, //call internal argument is function pointer
00061     Add,
00062     Sub,
00063     Mul,
00064     Div,
00065     Mod,
00066     Cgt, //takes two integers and compares for greater than pushes 1 if so, 0 if not
00067     Clt, //less than
00068     Cgte, //greater than or equal
00069     Clte,
00070     Ceq,
00071     Cneq,
00072     LoadStr, //argument is variable length string ending with 0. Pushes address onto stack
00073     LoadConst, //pushes the value pointed to by the argument
00074     StoreConst, //pops a value and stores it in the memory pointed to by the argument
00075     Load, //same as above, except the address is popped first. 
00076     Store,
00077     Swap, 
00078     New, //pushes a pointer to free memory for an integer
00079     NewVar, //pushes a pointer to memory. Size is specified by argument
00080     Delete, //pops a pointer and frees it. 
00081     Pick, //takes an integer position from the stack. Goes that many slots back in the stack and peeks at the value, and then pushes it on the top of the stack
00082     Ret //exit
00083 };
00084 
00085 typedef void (*BuiltinFunction)(void);
00086 typedef struct
00087 {
00088     char name[12];
00089     enum Type{
00090         Constant,
00091         ConstantString,
00092         Builtin,
00093         Function
00094     } type;
00095     union valueunion{
00096         int intvalue;
00097         BuiltinFunction builtin;
00098         char *string;
00099     } value;
00100 } WordKey;
00101 
00102 /**
00103 BranchTarget tracks branches/labels. 
00104 When a beginning conditional/looping structure is found, it adds a branch target to the list with `target` set to point to the relevant branch target in codeblock
00105 When an ending structure is found, it replaces the branch target(which starts at -1) with the actual branch address,
00106 **/
00107 typedef struct TargetNode
00108 {
00109     int target; //position inside of codeblock. Can't use pointers because life is cruel and the block could be reallocated at anytime. 
00110     TargetNode* previous; //previous instead of next because we're going to "destroy" this list in reverse
00111 } BranchTarget;  
00112 
00113 extern ErrorType pl_error;
00114 
00115 int pl_shell();
00116 
00117 static inline int is_whitespace(char c){
00118     return (c==' ') || (c=='\t') || (c=='\n') || (c=='\r');
00119 }
00120 
00121 static inline int is_numeric(char c){
00122     return (c>='0') && (c<='9');
00123 }
00124 
00125 static inline int is_alpha(char c){
00126     return ((c>='a') && (c<='z')) || ((c>='A') && (c<='Z'));
00127 }
00128 
00129 static inline int is_identifier(char c){
00130     return is_alpha(c) || is_numeric(c) || (c=='_');
00131 }
00132 
00133 static inline int is_quote(char c){
00134     return (c=='\"') || (c=='\'');
00135 }
00136 int forth_execute(uint8_t* block, int length);
00137 WordKey *pl_lookup(char* name);
00138 int pl_pop();
00139 void pl_push(int val);
00140 
00141 
00142 
00143 //builtin functions
00144 void bi_print();
00145 
00146 
00147 #endif