# Built-in variables
nextVarAddr = 1
-HERE = nextVarAddr; nextVarAddr += 1
+H = nextVarAddr; nextVarAddr += 1
LATEST = nextVarAddr; nextVarAddr += 1
RSP0 = nextVarAddr # bottom of RS
PSP0 = RSP0 + size_RS # bottom of PS
TIB = PSP0 + size_PS # address of terminal input buffer
-mem[HERE] = TIB + size_TIB # location of bottom of dictionary
+mem[H] = TIB + size_TIB # location of bottom of dictionary
mem[LATEST] = 0 # no previous definition
-DICT = mem[HERE] # Save bottom of dictionary as constant
+DICT = mem[H] # Save bottom of dictionary as constant
# VM registers
type Reg
F_LENMASK = 127
function createHeader(name::AbstractString, flags::Int64)
- mem[mem[HERE]] = mem[LATEST]
- mem[LATEST] = mem[HERE]
- mem[HERE] += 1
+ mem[mem[H]] = mem[LATEST]
+ mem[LATEST] = mem[H]
+ mem[H] += 1
- mem[mem[HERE]] = length(name) | flags; mem[HERE] += 1
- putString(name, mem[HERE]); mem[HERE] += length(name)
+ mem[mem[H]] = length(name) | flags; mem[H] += 1
+ putString(name, mem[H]); mem[H] += length(name)
end
function defPrimWord(name::AbstractString, f::Function; flags::Int64=0)
createHeader(name, flags)
- codeWordAddr = mem[HERE]
+ codeWordAddr = mem[H]
mem[codeWordAddr] = defPrim(f, name=name)
- mem[HERE] += 1
+ mem[H] += 1
return codeWordAddr
end
function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
createHeader(name, flags)
- addr = mem[HERE]
- mem[mem[HERE]] = DOCOL
- mem[HERE] += 1
+ addr = mem[H]
+ mem[mem[H]] = DOCOL
+ mem[H] += 1
for wordAddr in wordAddrs
- mem[mem[HERE]] = wordAddr
- mem[HERE] += 1
+ mem[mem[H]] = wordAddr
+ mem[H] += 1
end
return addr
function defNewVar(name::AbstractString, initial::Int64; flags::Int64=0)
createHeader(name, flags)
- codeWordAddr = mem[HERE]
- varAddr = mem[HERE] + 1
+ codeWordAddr = mem[H]
+ varAddr = mem[H] + 1
- mem[mem[HERE]] = DOVAR; mem[HERE] += 1
- mem[mem[HERE]] = initial; mem[HERE] += 1
+ mem[mem[H]] = DOVAR; mem[H] += 1
+ mem[mem[H]] = initial; mem[H] += 1
return varAddr, codeWordAddr
end
function defConst(name::AbstractString, val::Int64; flags::Int64=0)
createHeader(name, flags)
- codeWordAddr = mem[HERE]
+ codeWordAddr = mem[H]
- mem[mem[HERE]] = DOCON; mem[HERE] += 1
- mem[mem[HERE]] = val; mem[HERE] += 1
+ mem[mem[H]] = DOCON; mem[H] += 1
+ mem[mem[H]] = val; mem[H] += 1
return codeWordAddr
end
# Dictionary entries for core built-in variables, constants
-HERE_CFA = defExistingVar("HERE", HERE)
+H_CFA = defExistingVar("H", H)
LATEST_CFA = defExistingVar("LATEST", LATEST)
PSP0_CFA = defConst("PSP0", PSP0)
end)
COMMA = defPrimWord(",", () -> begin
- mem[mem[HERE]] = popPS()
- mem[HERE] += 1
+ mem[mem[H]] = popPS()
+ mem[H] += 1
return NEXT
end)
mem[TOIN] += 1
end
- countAddr = mem[HERE]
- addr = mem[HERE]+1
+ countAddr = mem[H]
+ addr = mem[H]+1
# Start reading in word
count = 0
delim = popPS()
# Chew up initial occurrences of delim
- addr = mem[HERE]
+ addr = mem[H]
# Start reading input stream
count = 0
: DEPTH PSP@ PSP0 - ;
+: HERE H @ ;
+
: '\n' 10 ;
: BL 32 ;
: IF IMMEDIATE
['] 0BRANCH , \ compile 0BRANCH
- HERE @ \ save location of the offset on the stack
+ HERE \ save location of the offset on the stack
0 , \ compile a dummy offset
;
: THEN IMMEDIATE
DUP
- HERE @ SWAP - \ calculate the offset from the address saved on the stack
+ HERE SWAP - \ calculate the offset from the address saved on the stack
SWAP ! \ store the offset in the back-filled location
;
: ELSE IMMEDIATE
['] BRANCH , \ definite branch to just over the false-part
- HERE @ \ save location of the offset on the stack
+ HERE \ save location of the offset on the stack
0 , \ compile a dummy offset
SWAP \ now back-fill the original (IF) offset
DUP \ same as for THEN word above
- HERE @ SWAP -
+ HERE SWAP -
SWAP !
;
: BEGIN IMMEDIATE
- HERE @ \ save location on the stack
+ HERE \ save location on the stack
;
: UNTIL IMMEDIATE
['] 0BRANCH , \ compile 0BRANCH
- HERE @ - \ calculate the offset from the address saved on the stack
+ HERE - \ calculate the offset from the address saved on the stack
, \ compile the offset here
;
: AGAIN IMMEDIATE
['] BRANCH , \ compile BRANCH
- HERE @ - \ calculate the offset back
+ HERE - \ calculate the offset back
, \ compile the offset here
;
: WHILE IMMEDIATE
['] 0BRANCH , \ compile 0BRANCH
- HERE @ \ save location of the offset2 on the stack
+ HERE \ save location of the offset2 on the stack
0 , \ compile a dummy offset2
;
: REPEAT IMMEDIATE
['] BRANCH , \ compile BRANCH
SWAP \ get the original offset (from BEGIN)
- HERE @ - , \ and compile it after BRANCH
+ HERE - , \ and compile it after BRANCH
DUP
- HERE @ SWAP - \ calculate the offset2
+ HERE SWAP - \ calculate the offset2
SWAP ! \ and back-fill it in the original location
;
: DO IMMEDIATE
['] LIT , -1 , [COMPILE] IF
['] >R , ['] >R ,
- ['] LIT , HERE @ 0 , ['] >R ,
- HERE @
+ ['] LIT , HERE 0 , ['] >R ,
+ HERE
;
: ?DO IMMEDIATE
['] 2DUP , ['] - , [COMPILE] IF
['] >R , ['] >R ,
- ['] LIT , HERE @ 0 , ['] >R ,
- HERE @
+ ['] LIT , HERE 0 , ['] >R ,
+ HERE
;
: I RSP@ 3 - @ ;
: ?LEAVE IMMEDIATE
['] 0BRANCH , 13 ,
['] R> , ['] RDROP , ['] RDROP ,
- ['] LIT , HERE @ 7 + , ['] DUP , ['] -ROT , ['] - , ['] SWAP , ['] ! ,
+ ['] LIT , HERE 7 + , ['] DUP , ['] -ROT , ['] - , ['] SWAP , ['] ! ,
['] BRANCH ,
0 ,
;
[COMPILE] THEN
\ Branch back to begining of loop kernel
- ['] 0BRANCH , HERE @ - ,
+ ['] 0BRANCH , HERE - ,
\ Clean up
['] RDROP , ['] RDROP , ['] RDROP ,
\ Record address of loop end for any LEAVEs to use
- HERE @ SWAP !
+ HERE SWAP !
[COMPILE] ELSE
['] 2DROP , \ Clean up if loop was entirely skipped (?DO)
( C, appends a byte to the current compiled word. )
: C,
- HERE @ C!
- 1 HERE +!
+ HERE C!
+ 1 H +!
;
: S" IMMEDIATE ( -- addr len )
STATE @ IF ( compiling? )
['] LITSTRING , ( compile LITSTRING )
- HERE @ ( save the address of the length word on the stack )
+ HERE ( save the address of the length word on the stack )
0 , ( dummy length - we don't know what it is yet )
BEGIN
REPEAT
DROP ( drop the double quote character at the end )
DUP ( get the saved address of the length word )
- HERE @ SWAP - ( calculate the length )
+ HERE SWAP - ( calculate the length )
1- ( subtract 1 (because we measured from the start of the length word) )
SWAP ! ( and back-fill the length location )
ELSE ( immediate mode )
- HERE @ ( get the start address of the temporary space )
+ HERE ( get the start address of the temporary space )
BEGIN
>IN @ #TIB @ >= IF \ End of TIB?
1+ ( increment address )
REPEAT
DROP ( drop the final " character )
- HERE @ - ( calculate the length )
- HERE @ ( push the start address )
+ HERE - ( calculate the length )
+ HERE ( push the start address )
SWAP ( addr len )
THEN
;
;
: ALLOT ( n -- )
- HERE +! ( adds n to HERE, after this the old value of HERE is still on the stack )
+ H +! ( adds n to H, after this the old value of H is still on the stack )
;
: VARIABLE
: FORGET
BL WORD FIND ( find the word, gets the dictionary entry address )
DUP @ LATEST ! ( set LATEST to point to the previous word )
- HERE ! ( and store HERE with the dictionary address )
+ H ! ( and store H with the dictionary address )
;
( DUMP ------------------------------------------------------------------------ )
( Now we search again, looking for the next word in the dictionary. This gives us
the length of the word that we will be decompiling. (Well, mostly it does). )
- HERE @ ( address of the end of the last compiled word )
+ HERE ( address of the end of the last compiled word )
LATEST @ ( word last curr )
BEGIN
2 PICK ( word last curr word )
( MEMORY ------------------------------------------------------------------ )
: UNUSED ( -- cells )
- MEMSIZE HERE @ - ;
+ MEMSIZE HERE - ;
The Lambda Lab / projects / forth.jl.git / commitdiff