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mirror of https://github.com/kanaka/mal.git synced 2024-10-27 06:40:14 +03:00
mal/impls/basic/step2_eval.in.bas
Joel Martin 8a19f60386 Move implementations into impls/ dir
- Reorder README to have implementation list after "learning tool"
  bullet.

- This also moves tests/ and libs/ into impls. It would be preferrable
  to have these directories at the top level.  However, this causes
  difficulties with the wasm implementations which need pre-open
  directories and have trouble with paths starting with "../../". So
  in lieu of that, symlink those directories to the top-level.

- Move the run_argv_test.sh script into the tests directory for
  general hygiene.
2020-02-10 23:50:16 -06:00

253 lines
4.9 KiB
QBasic
Executable File

GOTO MAIN
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 $INCLUDE: 'debug.in.bas'
REM READ(A$) -> R
MAL_READ:
GOSUB READ_STR
RETURN
REM EVAL_AST(A, E) -> R
SUB EVAL_AST
LV=LV+1
REM push A and E on the stack
Q=E:GOSUB PUSH_Q
GOSUB PUSH_A
IF ER<>-2 THEN GOTO EVAL_AST_RETURN
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 INC_REF_R
GOTO EVAL_AST_RETURN
EVAL_AST_SYMBOL:
H=E:K=A:GOSUB HASHMAP_GET
IF R3=0 THEN R=-1:ER=-1:E$="'"+S$(Z%(A+1))+"' not found":GOTO EVAL_AST_RETURN
GOSUB INC_REF_R
GOTO EVAL_AST_RETURN
EVAL_AST_SEQ:
REM setup the stack for the loop
GOSUB MAP_LOOP_START
EVAL_AST_SEQ_LOOP:
REM check if we are done evaluating the source sequence
IF Z%(A+1)=0 THEN GOTO EVAL_AST_SEQ_LOOP_DONE
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
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
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 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)
GOTO EVAL_AST_SEQ_LOOP
EVAL_AST_SEQ_LOOP_DONE:
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
GOSUB POP_A
GOSUB POP_Q:E=Q
LV=LV-1
END SUB
REM EVAL(A, E) -> R
SUB EVAL
LV=LV+1: REM track basic return stack level
REM push A and E on the stack
Q=E:GOSUB PUSH_Q
GOSUB PUSH_A
IF ER<>-2 THEN GOTO EVAL_RETURN
REM AZ=A:B=1:GOSUB PR_STR
REM PRINT "EVAL: "+R$+" [A:"+STR$(A)+", LV:"+STR$(LV)+"]"
GOSUB LIST_Q
IF R THEN GOTO APPLY_LIST
REM ELSE
CALL EVAL_AST
GOTO EVAL_RETURN
APPLY_LIST:
GOSUB EMPTY_Q
IF R THEN R=A:GOSUB INC_REF_R:GOTO EVAL_RETURN
EVAL_INVOKE:
CALL EVAL_AST
W=R
REM if error, return f/args for release by caller
IF ER<>-2 THEN GOTO EVAL_RETURN
AR=Z%(R+1): REM rest
F=Z%(R+2)
GOSUB TYPE_F
IF T<>9 THEN R=-1:ER=-1:E$="apply of non-function":GOTO EVAL_INVOKE_DONE
GOSUB DO_FUNCTION
EVAL_INVOKE_DONE:
AY=W:GOSUB RELEASE
GOTO EVAL_RETURN
EVAL_RETURN:
LV=LV-1: REM track basic return stack level
REM trigger GC
#cbm T=FRE(0)
#qbasic T=0
REM pop A and E off the stack
GOSUB POP_A
GOSUB POP_Q:E=Q
END SUB
REM DO_FUNCTION(F, AR)
DO_FUNCTION:
AZ=F:GOSUB PR_STR
F$=R$
AZ=AR:GOSUB PR_STR
AR$=R$
REM Get the function number
G=Z%(F+1)
REM Get argument values
A=Z%(Z%(AR+2)+1)
B=Z%(Z%(Z%(AR+1)+2)+1)
REM Switch on the function number
IF G=1 THEN GOTO DO_ADD
IF G=2 THEN GOTO DO_SUB
IF G=3 THEN GOTO DO_MULT
IF G=4 THEN GOTO DO_DIV
ER=-1:E$="unknown function"+STR$(G):RETURN
DO_ADD:
T=2:L=A+B:GOSUB ALLOC
GOTO DO_FUNCTION_DONE
DO_SUB:
T=2:L=A-B:GOSUB ALLOC
GOTO DO_FUNCTION_DONE
DO_MULT:
T=2:L=A*B:GOSUB ALLOC
GOTO DO_FUNCTION_DONE
DO_DIV:
T=2:L=A/B:GOSUB ALLOC
GOTO DO_FUNCTION_DONE
DO_FUNCTION_DONE:
RETURN
REM PRINT(A) -> R$
MAL_PRINT:
AZ=A:B=1:GOSUB PR_STR
RETURN
REM REP(A$) -> R$
REM Assume D has repl_env
SUB REP
R1=-1:R2=-1
GOSUB MAL_READ
R1=R
IF ER<>-2 THEN GOTO REP_DONE
A=R:E=D:CALL EVAL
R2=R
IF ER<>-2 THEN GOTO REP_DONE
A=R:GOSUB MAL_PRINT
REP_DONE:
REM Release memory from MAL_READ and EVAL
AY=R2:GOSUB RELEASE
AY=R1:GOSUB RELEASE
END SUB
REM MAIN program
MAIN:
GOSUB INIT_MEMORY
LV=0
REM create repl_env
GOSUB HASHMAP:D=R
REM + function
T=9:L=1:GOSUB ALLOC: REM native function
H=D:B$="+":C=R:GOSUB ASSOC1_S:D=R
REM - function
T=9:L=2:GOSUB ALLOC: REM native function
H=D:B$="-":C=R:GOSUB ASSOC1_S:D=R
REM * function
T=9:L=3:GOSUB ALLOC: REM native function
H=D:B$="*":C=R:GOSUB ASSOC1_S:D=R
REM / function
T=9:L=4:GOSUB ALLOC: REM native function
H=D:B$="/":C=R:GOSUB ASSOC1_S:D=R
ZT=ZI: REM top of memory after base repl_env
REPL_LOOP:
A$="user> ":GOSUB READLINE: REM call input parser
IF EZ=1 THEN GOTO QUIT
IF R$="" THEN GOTO REPL_LOOP
A$=R$:CALL REP: REM call REP
IF ER<>-2 THEN GOSUB PRINT_ERROR:GOTO REPL_LOOP
PRINT R$
GOTO REPL_LOOP
QUIT:
REM GOSUB PR_MEMORY_SUMMARY_SMALL
#cbm END
#qbasic SYSTEM
PRINT_ERROR:
PRINT "Error: "+E$
ER=-2:E$=""
RETURN