GOTO MAIN
-REM $INCLUDE: 'readline.in.bas'
+REM $INCLUDE: 'mem.in.bas'
REM $INCLUDE: 'types.in.bas'
+REM $INCLUDE: 'readline.in.bas'
REM $INCLUDE: 'reader.in.bas'
REM $INCLUDE: 'printer.in.bas'
REM $INCLUDE: 'env.in.bas'
RETURN
REM EVAL_AST(A, E) -> R
-REM called using GOTO to avoid basic return address stack usage
-REM top of stack should have return label index
-EVAL_AST:
+SUB EVAL_AST
REM push A and E on the stack
- X=X+2:X%(X-1)=E:X%(X)=A
+ Q=E:GOSUB PUSH_Q
+ GOSUB PUSH_A
IF ER<>-2 THEN GOTO EVAL_AST_RETURN
- GOSUB DEREF_A
-
- T=Z%(A,0)AND31
+ GOSUB TYPE_A
IF T=5 THEN GOTO EVAL_AST_SYMBOL
IF T>=6 AND T<=8 THEN GOTO EVAL_AST_SEQ
REM scalar: deref to actual value and inc ref cnt
- R=A:GOSUB DEREF_R
- Z%(R,0)=Z%(R,0)+32
+ R=A
+ GOSUB INC_REF_R
GOTO EVAL_AST_RETURN
EVAL_AST_SYMBOL:
- K=A:GOSUB ENV_GET
+ K=A:GOTO ENV_GET
+ ENV_GET_RETURN:
GOTO EVAL_AST_RETURN
EVAL_AST_SEQ:
- REM allocate the first entry (T already set above)
- L=0:N=0:GOSUB ALLOC
-
- REM make space on the stack
- X=X+4
- REM push type of sequence
- X%(X-3)=T
- REM push sequence index
- X%(X-2)=-1
- REM push future return value (new sequence)
- X%(X-1)=R
- REM push previous new sequence entry
- X%(X)=R
+ REM setup the stack for the loop
+ GOSUB MAP_LOOP_START
EVAL_AST_SEQ_LOOP:
- REM update index
- X%(X-2)=X%(X-2)+1
-
REM check if we are done evaluating the source sequence
- IF Z%(A,1)=0 THEN GOTO EVAL_AST_SEQ_LOOP_DONE
-
- REM if hashmap, skip eval of even entries (keys)
- IF (X%(X-3)=8) AND ((X%(X-2) AND 1)=0) THEN GOTO EVAL_AST_DO_REF
- GOTO EVAL_AST_DO_EVAL
+ IF Z%(A+1)=0 THEN GOTO EVAL_AST_SEQ_LOOP_DONE
- EVAL_AST_DO_REF:
- R=A+1:GOSUB DEREF_R: REM deref to target of referred entry
- Z%(R,0)=Z%(R,0)+32: REM inc ref cnt of referred value
- GOTO EVAL_AST_ADD_VALUE
+ REM call EVAL for each entry
+ GOSUB PUSH_A
+ IF T<>8 THEN A=Z%(A+2)
+ IF T=8 THEN A=Z%(A+3)
+ Q=T:GOSUB PUSH_Q: REM push/save type
+ CALL EVAL
+ GOSUB POP_Q:T=Q: REM pop/restore type
+ GOSUB POP_A
+ M=R
- EVAL_AST_DO_EVAL:
- REM call EVAL for each entry
- A=A+1:GOSUB EVAL
- A=A-1
- GOSUB DEREF_R: REM deref to target of evaluated entry
+ REM if error, release the unattached element
+ REM TODO: is R=0 correct?
+ IF ER<>-2 THEN AY=R:GOSUB RELEASE:R=0:GOTO EVAL_AST_SEQ_LOOP_DONE
- EVAL_AST_ADD_VALUE:
+ REM for hash-maps, copy the key (inc ref since we are going to
+ REM release it below)
+ IF T=8 THEN N=M:M=Z%(A+2):Z%(M)=Z%(M)+32
- REM update previous value pointer to evaluated entry
- Z%(X%(X)+1,1)=R
- IF ER<>-2 THEN GOTO EVAL_AST_SEQ_LOOP_DONE
-
- REM allocate the next entry
- REM same new sequence entry type
- T=X%(X-3):L=0:N=0:GOSUB ALLOC
-
- REM update previous sequence entry value to point to new entry
- Z%(X%(X),1)=R
- REM update previous ptr to current entry
- X%(X)=R
+ REM update the return sequence structure
+ REM release N (and M if T=8) since seq takes full ownership
+ C=1:GOSUB MAP_LOOP_UPDATE
REM process the next sequence entry from source list
- A=Z%(A,1)
+ A=Z%(A+1)
GOTO EVAL_AST_SEQ_LOOP
EVAL_AST_SEQ_LOOP_DONE:
- REM if no error, get return value (new seq)
- IF ER=-2 THEN R=X%(X-1)
- REM otherwise, free the return value and return nil
- IF ER<>-2 THEN R=0:AY=X%(X-1):GOSUB RELEASE
-
- REM pop previous, return, index and type
- X=X-4
+ REM cleanup stack and get return value
+ GOSUB MAP_LOOP_DONE
GOTO EVAL_AST_RETURN
EVAL_AST_RETURN:
REM pop A and E off the stack
- E=X%(X-1):A=X%(X):X=X-2
+ GOSUB POP_A
+ GOSUB POP_Q:E=Q
+END SUB
- REM pop EVAL AST return label/address
- RN=X%(X):X=X-1
- ON RN GOTO EVAL_AST_RETURN_1,EVAL_AST_RETURN_2,EVAL_AST_RETURN_3
-
-REM EVAL(A, E)) -> R
-EVAL:
+REM EVAL(A, E) -> R
+SUB EVAL
LV=LV+1: REM track basic return stack level
REM push A and E on the stack
- X=X+2:X%(X-1)=E:X%(X)=A
+ Q=E:GOSUB PUSH_Q
+ GOSUB PUSH_A
REM PRINT "EVAL A:"+STR$(A)+",X:"+STR$(X)+",LV:"+STR$(LV)+",FRE:"+STR$(FRE(0))
EVAL_TCO_RECUR:
- REM AZ=A:PR=1:GOSUB PR_STR
- REM PRINT "EVAL: "+R$+" [A:"+STR$(A)+", LV:"+STR$(LV)+"]"
+ IF ER<>-2 THEN GOTO EVAL_RETURN
- GOSUB DEREF_A
+ REM AZ=A:B=1:GOSUB PR_STR
+ REM PRINT "EVAL: "+R$+" [A:"+STR$(A)+", LV:"+STR$(LV)+"]"
GOSUB LIST_Q
IF R THEN GOTO APPLY_LIST
REM ELSE
- REM push EVAL_AST return label/address
- X=X+1:X%(X)=1
- GOTO EVAL_AST
- EVAL_AST_RETURN_1:
-
+ CALL EVAL_AST
GOTO EVAL_RETURN
APPLY_LIST:
GOSUB EMPTY_Q
- IF R THEN R=A:Z%(R,0)=Z%(R,0)+32:GOTO EVAL_RETURN
+ IF R THEN R=A:GOSUB INC_REF_R:GOTO EVAL_RETURN
- A0=A+1
- R=A0:GOSUB DEREF_R:A0=R
+ A0=Z%(A+2)
REM get symbol in A$
- IF (Z%(A0,0)AND31)<>5 THEN A$=""
- IF (Z%(A0,0)AND31)=5 THEN A$=S$(Z%(A0,1))
+ IF (Z%(A0)AND 31)<>5 THEN A$=""
+ IF (Z%(A0)AND 31)=5 THEN A$=S$(Z%(A0+1))
IF A$="def!" THEN GOTO EVAL_DEF
IF A$="let*" THEN GOTO EVAL_LET
GOTO EVAL_INVOKE
EVAL_GET_A3:
- A3=Z%(Z%(Z%(A,1),1),1)+1
- R=A3:GOSUB DEREF_R:A3=R
+ A3=Z%(Z%(Z%(Z%(A+1)+1)+1)+2)
EVAL_GET_A2:
- A2=Z%(Z%(A,1),1)+1
- R=A2:GOSUB DEREF_R:A2=R
+ A2=Z%(Z%(Z%(A+1)+1)+2)
EVAL_GET_A1:
- A1=Z%(A,1)+1
- R=A1:GOSUB DEREF_R:A1=R
+ A1=Z%(Z%(A+1)+2)
RETURN
EVAL_DEF:
REM PRINT "def!"
GOSUB EVAL_GET_A2: REM set A1 and A2
- X=X+1:X%(X)=A1: REM push A1
- A=A2:GOSUB EVAL: REM eval a2
- A1=X%(X):X=X-1: REM pop A1
+ Q=A1:GOSUB PUSH_Q
+ A=A2:CALL EVAL: REM eval a2
+ GOSUB POP_Q:A1=Q
IF ER<>-2 THEN GOTO EVAL_RETURN
REM set a1 in env to a2
- K=A1:V=R:GOSUB ENV_SET
+ K=A1:C=R:GOSUB ENV_SET
GOTO EVAL_RETURN
EVAL_LET:
REM PRINT "let*"
GOSUB EVAL_GET_A2: REM set A1 and A2
- X=X+1:X%(X)=A2: REM push/save A2
+ Q=A2:GOSUB PUSH_Q: REM push/save A2
REM create new environment with outer as current environment
- O=E:GOSUB ENV_NEW
+ C=E:GOSUB ENV_NEW
E=R
EVAL_LET_LOOP:
- IF Z%(A1,1)=0 THEN GOTO EVAL_LET_LOOP_DONE
+ IF Z%(A1+1)=0 THEN GOTO EVAL_LET_LOOP_DONE
- X=X+1:X%(X)=A1: REM push A1
+ Q=A1:GOSUB PUSH_Q: REM push A1
REM eval current A1 odd element
- A=Z%(A1,1)+1:GOSUB EVAL
- A1=X%(X):X=X-1: REM pop A1
+ A=Z%(Z%(A1+1)+2):CALL EVAL
+ GOSUB POP_Q:A1=Q: REM pop A1
+
+ IF ER<>-2 THEN GOTO EVAL_LET_LOOP_DONE
- REM set environment: even A1 key to odd A1 eval'd above
- K=A1+1:V=R:GOSUB ENV_SET
+ REM set key/value in the environment
+ K=Z%(A1+2):C=R:GOSUB ENV_SET
AY=R:GOSUB RELEASE: REM release our use, ENV_SET took ownership
REM skip to the next pair of A1 elements
- A1=Z%(Z%(A1,1),1)
+ A1=Z%(Z%(A1+1)+1)
GOTO EVAL_LET_LOOP
EVAL_LET_LOOP_DONE:
- A2=X%(X):X=X-1: REM pop A2
- A=A2:GOSUB EVAL: REM eval A2 using let_env
+ GOSUB POP_Q:A2=Q: REM pop A2
+ A=A2:CALL EVAL: REM eval A2 using let_env
GOTO EVAL_RETURN
EVAL_DO:
- A=Z%(A,1): REM rest
+ A=Z%(A+1): REM rest
- REM push EVAL_AST return label/address
- X=X+1:X%(X)=2
- GOTO EVAL_AST
- REM return label/address already popped by EVAL_AST
- EVAL_AST_RETURN_2:
+ CALL EVAL_AST
- X=X+1:X%(X)=R: REM push eval'd list
+ GOSUB PUSH_R: REM push eval'd list
A=R:GOSUB LAST: REM return the last element
- AY=X%(X):X=X-1: REM pop eval'd list
+ GOSUB POP_Q:AY=Q: REM pop eval'd list
GOSUB RELEASE: REM release the eval'd list
GOTO EVAL_RETURN
EVAL_IF:
GOSUB EVAL_GET_A1: REM set A1
- REM push A
- X=X+1:X%(X)=A
- A=A1:GOSUB EVAL
- REM pop A
- A=X%(X):X=X-1
- IF (R=0) OR (R=1) THEN GOTO EVAL_IF_FALSE
+ GOSUB PUSH_A: REM push/save A
+ A=A1:CALL EVAL
+ GOSUB POP_A: REM pop/restore A
+ IF (R=0) OR (R=2) THEN GOTO EVAL_IF_FALSE
EVAL_IF_TRUE:
AY=R:GOSUB RELEASE
EVAL_IF_FALSE:
AY=R:GOSUB RELEASE
REM if no false case (A3), return nil
- IF Z%(Z%(Z%(A,1),1),1)=0 THEN R=0:GOTO EVAL_RETURN
+ GOSUB COUNT
+ IF R<4 THEN R=0:GOSUB INC_REF_R:GOTO EVAL_RETURN
GOSUB EVAL_GET_A3: REM set A1 - A3 after EVAL
A=A3:GOTO EVAL_TCO_RECUR: REM TCO loop
EVAL_FN:
GOSUB EVAL_GET_A2: REM set A1 and A2
- A=A2:P=A1:GOSUB MAL_FUNCTION
+ T=10:L=A2:M=A1:N=E:GOSUB ALLOC: REM mal function
GOTO EVAL_RETURN
EVAL_INVOKE:
- REM push EVAL_AST return label/address
- X=X+1:X%(X)=3
- GOTO EVAL_AST
- EVAL_AST_RETURN_3:
+ CALL EVAL_AST
REM if error, return f/args for release by caller
IF ER<>-2 THEN GOTO EVAL_RETURN
REM push f/args for release after call
- X=X+1:X%(X)=R
+ GOSUB PUSH_R
- F=R+1
-
- AR=Z%(R,1): REM rest
- R=F:GOSUB DEREF_R:F=R
+ AR=Z%(R+1): REM rest
+ F=Z%(R+2)
REM if metadata, get the actual object
- IF (Z%(F,0)AND31)>=16 THEN F=Z%(F,1)
+ GOSUB TYPE_F
+ IF T=14 THEN F=Z%(F+1):GOSUB TYPE_F
- IF (Z%(F,0)AND31)=9 THEN GOTO EVAL_DO_FUNCTION
- IF (Z%(F,0)AND31)=10 THEN GOTO EVAL_DO_MAL_FUNCTION
+ ON T-8 GOTO EVAL_DO_FUNCTION,EVAL_DO_MAL_FUNCTION,EVAL_DO_MAL_FUNCTION
REM if error, pop and return f/args for release by caller
- R=X%(X):X=X-1
- ER=-1:ER$="apply of non-function":GOTO EVAL_RETURN
+ GOSUB POP_R
+ ER=-1:E$="apply of non-function":GOTO EVAL_RETURN
EVAL_DO_FUNCTION:
REM regular function
- IF Z%(F,1)<60 THEN GOSUB DO_FUNCTION:GOTO DO_TCO_FUNCTION_RETURN_EVAL
+ IF Z%(F+1)<60 THEN GOSUB DO_FUNCTION:GOTO EVAL_DO_FUNCTION_SKIP
REM for recur functions (apply, map, swap!), use GOTO
- IF Z%(F,1)>60 THEN X=X+1:X%(X)=2:GOTO DO_TCO_FUNCTION
- DO_TCO_FUNCTION_RETURN_EVAL:
+ IF Z%(F+1)>60 THEN CALL DO_TCO_FUNCTION
+ EVAL_DO_FUNCTION_SKIP:
REM pop and release f/args
- AY=X%(X):X=X-1:GOSUB RELEASE
+ GOSUB POP_Q:AY=Q
+ GOSUB RELEASE
GOTO EVAL_RETURN
EVAL_DO_MAL_FUNCTION:
- E4=E: REM save the current environment for release
+ Q=E:GOSUB PUSH_Q: REM save the current environment for release
- REM create new environ using env stored with function
- O=Z%(F+1,1):BI=Z%(F+1,0):EX=AR:GOSUB ENV_NEW_BINDS
+ REM create new environ using env and params stored in function
+ C=Z%(F+3):A=Z%(F+2):B=AR:GOSUB ENV_NEW_BINDS
REM release previous env if it is not the top one on the
REM stack (X%(X-2)) because our new env refers to it and
REM we no longer need to track it (since we are TCO recurring)
- IF E4<>X%(X-2) THEN AY=E4:GOSUB RELEASE
+ GOSUB POP_Q:AY=Q
+ GOSUB PEEK_Q_2
+ IF AY<>Q THEN GOSUB RELEASE
REM claim the AST before releasing the list containing it
- A=Z%(F,1):Z%(A,0)=Z%(A,0)+32
+ A=Z%(F+1):Z%(A)=Z%(A)+32
REM add AST to pending release queue to free as soon as EVAL
REM actually returns (LV+1)
- Y=Y+1:Y%(Y,0)=A:Y%(Y,1)=LV+1
+ LV=LV+1:GOSUB PEND_A_LV:LV=LV-1
REM pop and release f/args
- AY=X%(X):X=X-1:GOSUB RELEASE
+ GOSUB POP_Q:AY=Q
+ GOSUB RELEASE
REM A set above
E=R:GOTO EVAL_TCO_RECUR: REM TCO loop
EVAL_RETURN:
- REM AZ=R: PR=1: GOSUB PR_STR
+ REM AZ=R: B=1: GOSUB PR_STR
REM PRINT "EVAL_RETURN R: ["+R$+"] ("+STR$(R)+"), LV:"+STR$(LV)+",ER:"+STR$(ER)
REM release environment if not the top one on the stack
- IF E<>X%(X-1) THEN AY=E:GOSUB RELEASE
+ GOSUB PEEK_Q_1
+ IF E<>Q THEN AY=E:GOSUB RELEASE
LV=LV-1: REM track basic return stack level
GOSUB RELEASE_PEND
REM trigger GC
- TA=FRE(0)
+ #cbm T=FRE(0)
+ #qbasic T=0
REM pop A and E off the stack
- E=X%(X-1):A=X%(X):X=X-2
+ GOSUB POP_A
+ GOSUB POP_Q:E=Q
- RETURN
+END SUB
REM PRINT(A) -> R$
MAL_PRINT:
- AZ=A:PR=1:GOSUB PR_STR
+ AZ=A:B=1:GOSUB PR_STR
RETURN
REM RE(A$) -> R
REM Assume D has repl_env
REM caller must release result
RE:
- R1=0
+ R1=-1
GOSUB MAL_READ
R1=R
IF ER<>-2 THEN GOTO RE_DONE
- A=R:E=D:GOSUB EVAL
+ A=R:E=D:CALL EVAL
RE_DONE:
REM Release memory from MAL_READ
- IF R1<>0 THEN AY=R1:GOSUB RELEASE
+ AY=R1:GOSUB RELEASE
RETURN: REM caller must release result of EVAL
REM REP(A$) -> R$
REM Assume D has repl_env
-REP:
- R1=0:R2=0
- GOSUB MAL_READ
- R1=R
- IF ER<>-2 THEN GOTO REP_DONE
+SUB REP
+ R2=-1
- A=R:E=D:GOSUB EVAL
+ GOSUB RE
R2=R
IF ER<>-2 THEN GOTO REP_DONE
A=R:GOSUB MAL_PRINT
- RT$=R$
REP_DONE:
REM Release memory from MAL_READ and EVAL
- IF R2<>0 THEN AY=R2:GOSUB RELEASE
- IF R1<>0 THEN AY=R1:GOSUB RELEASE
- R$=RT$
- RETURN
+ AY=R2:GOSUB RELEASE
+END SUB
REM MAIN program
MAIN:
LV=0
REM create repl_env
- O=-1:GOSUB ENV_NEW:D=R
+ C=0:GOSUB ENV_NEW:D=R
REM core.EXT: defined in Basic
E=D:GOSUB INIT_CORE_NS: REM set core functions in repl_env
REPL_LOOP:
A$="user> ":GOSUB READLINE: REM call input parser
- IF EOF=1 THEN GOTO QUIT
+ IF EZ=1 THEN GOTO QUIT
+ IF R$="" THEN GOTO REPL_LOOP
- A$=R$:GOSUB REP: REM call REP
+ A$=R$:CALL REP: REM call REP
IF ER<>-2 THEN GOSUB PRINT_ERROR:GOTO REPL_LOOP
PRINT R$
GOTO REPL_LOOP
QUIT:
- REM P1=ZT: P2=-1: GOSUB PR_MEMORY
- GOSUB PR_MEMORY_SUMMARY
- END
+ REM GOSUB PR_MEMORY_SUMMARY_SMALL
+ #cbm END
+ #qbasic SYSTEM
PRINT_ERROR:
- PRINT "Error: "+ER$
- ER=-2:ER$=""
+ PRINT "Error: "+E$
+ ER=-2:E$=""
RETURN