basic: prepare ENV_GET for DEBUG-EVAL

Pass a BASIC string to ENV_GET and HASHMAP_GET (for DEBUG-EVAL).
Merge eval_find into eval_env.
Let HASHMAP_GET return its result into R for consistency.
Raise no exception from ENV_GET (for DEBUG-EVAL).

Move INC_REF_R outside of ENV_GET for clarity (the macroexpand part
will disappear soon anyway).

impls/basic/core.in.bas

@@ -380,10 +380,10 @@ DO_FUNCTION:
       GOTO DO_ASSOC_LOOP
   DO_GET:
     IF A=0 THEN R=0:GOTO INC_REF_R
-    H=A:K=B:GOSUB HASHMAP_GET
+    H=A:B$=S$(Z%(B+1)):GOSUB HASHMAP_GET
     GOTO INC_REF_R
   DO_CONTAINS:
-    H=A:K=B:GOSUB HASHMAP_CONTAINS
+    H=A:B$=S$(Z%(B+1)):GOSUB HASHMAP_CONTAINS
     GOTO RETURN_TRUE_FALSE
   DO_KEYS:
     T1=0

impls/basic/env.in.bas

@@ -63,27 +63,17 @@ ENV_SET_S:
   R=C
   RETURN
 
-REM ENV_FIND(E, K) -> R
-REM   Returns environment (R) containing K. If found, value found is
-REM   in R4
-SUB ENV_FIND
+REM ENV_GET(E, B$) -> R
+REM   - R3=1 if the key was found, else 0
+SUB ENV_GET
   T=E
   ENV_FIND_LOOP:
     H=Z%(T+1)
     REM More efficient to use GET for value (R) and contains? (R3)
     GOSUB HASHMAP_GET
-    REM if we found it, save value in R4 for ENV_GET
-    IF R3=1 THEN R4=R:R=T:GOTO ENV_FIND_DONE
+    REM if we found it, return it
+    IF R3=1 THEN GOTO ENV_FIND_DONE
     T=Z%(T+2): REM get outer environment
     IF T>0 THEN GOTO ENV_FIND_LOOP
-    R=-1
   ENV_FIND_DONE:
 END SUB
-
-REM ENV_GET(E, K) -> R
-ENV_GET:
-  CALL ENV_FIND
-  IF R=-1 THEN ER=-1:E$="'"+S$(Z%(K+1))+"' not found":GOTO ENV_GET_RETURN
-  R=R4
-  GOSUB INC_REF_R
-  GOTO ENV_GET_RETURN

impls/basic/step2_eval.in.bas

@@ -28,8 +28,8 @@ SUB EVAL_AST
   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
+    H=E:B$=S$(Z%(A+1)):GOSUB HASHMAP_GET
+    IF R3=0 THEN R=-1:ER=-1:E$="'"+B$+"' not found":GOTO EVAL_AST_RETURN
     GOSUB INC_REF_R
     GOTO EVAL_AST_RETURN
 

impls/basic/step3_env.in.bas

@@ -29,8 +29,9 @@ SUB EVAL_AST
   GOTO EVAL_AST_RETURN
 
   EVAL_AST_SYMBOL:
-    K=A:GOTO ENV_GET
-    ENV_GET_RETURN:
+    B$=S$(Z%(A+1)):CALL ENV_GET
+    IF R3=0 THEN R=-1:ER=-1:E$="'"+B$+"' not found":GOTO EVAL_AST_RETURN
+    GOSUB INC_REF_R
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/step4_if_fn_do.in.bas

@@ -30,8 +30,9 @@ SUB EVAL_AST
   GOTO EVAL_AST_RETURN
 
   EVAL_AST_SYMBOL:
-    K=A:GOTO ENV_GET
-    ENV_GET_RETURN:
+    B$=S$(Z%(A+1)):CALL ENV_GET
+    IF R3=0 THEN R=-1:ER=-1:E$="'"+B$+"' not found":GOTO EVAL_AST_RETURN
+    GOSUB INC_REF_R
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/step5_tco.in.bas

@@ -30,8 +30,9 @@ SUB EVAL_AST
   GOTO EVAL_AST_RETURN
 
   EVAL_AST_SYMBOL:
-    K=A:GOTO ENV_GET
-    ENV_GET_RETURN:
+    B$=S$(Z%(A+1)):CALL ENV_GET
+    IF R3=0 THEN R=-1:ER=-1:E$="'"+B$+"' not found":GOTO EVAL_AST_RETURN
+    GOSUB INC_REF_R
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/step6_file.in.bas

@@ -30,8 +30,9 @@ SUB EVAL_AST
   GOTO EVAL_AST_RETURN
 
   EVAL_AST_SYMBOL:
-    K=A:GOTO ENV_GET
-    ENV_GET_RETURN:
+    B$=S$(Z%(A+1)):CALL ENV_GET
+    IF R3=0 THEN R=-1:ER=-1:E$="'"+B$+"' not found":GOTO EVAL_AST_RETURN
+    GOSUB INC_REF_R
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/step7_quote.in.bas

@@ -143,8 +143,9 @@ SUB EVAL_AST
   GOTO EVAL_AST_RETURN
 
   EVAL_AST_SYMBOL:
-    K=A:GOTO ENV_GET
-    ENV_GET_RETURN:
+    B$=S$(Z%(A+1)):CALL ENV_GET
+    IF R3=0 THEN R=-1:ER=-1:E$="'"+B$+"' not found":GOTO EVAL_AST_RETURN
+    GOSUB INC_REF_R
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/step8_macros.in.bas

@@ -138,12 +138,13 @@ SUB MACROEXPAND
     REM symbol? in first position
     IF (Z%(B)AND 31)<>5 THEN GOTO MACROEXPAND_DONE
     REM defined in environment?
-    K=B:CALL ENV_FIND
-    IF R=-1 THEN GOTO MACROEXPAND_DONE
-    B=R4
+    B$=S$(Z%(B+1)):CALL ENV_GET
+    IF R3=0 THEN GOTO MACROEXPAND_DONE
+    B=R
     REM macro?
     IF (Z%(B)AND 31)<>11 THEN GOTO MACROEXPAND_DONE
 
+    GOSUB INC_REF_R
     F=B:AR=Z%(A+1):CALL APPLY
     A=R
 
@@ -177,8 +178,9 @@ SUB EVAL_AST
   GOTO EVAL_AST_RETURN
 
   EVAL_AST_SYMBOL:
-    K=A:GOTO ENV_GET
-    ENV_GET_RETURN:
+    B$=S$(Z%(A+1)):CALL ENV_GET
+    IF R3=0 THEN R=-1:ER=-1:E$="'"+B$+"' not found":GOTO EVAL_AST_RETURN
+    GOSUB INC_REF_R
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/step9_try.in.bas

@@ -138,12 +138,13 @@ SUB MACROEXPAND
     REM symbol? in first position
     IF (Z%(B)AND 31)<>5 THEN GOTO MACROEXPAND_DONE
     REM defined in environment?
-    K=B:CALL ENV_FIND
-    IF R=-1 THEN GOTO MACROEXPAND_DONE
-    B=R4
+    B$=S$(Z%(B+1)):CALL ENV_GET
+    IF R3=0 THEN GOTO MACROEXPAND_DONE
+    B=R
     REM macro?
     IF (Z%(B)AND 31)<>11 THEN GOTO MACROEXPAND_DONE
 
+    GOSUB INC_REF_R
     F=B:AR=Z%(A+1):CALL APPLY
     A=R
 
@@ -177,8 +178,9 @@ SUB EVAL_AST
   GOTO EVAL_AST_RETURN
 
   EVAL_AST_SYMBOL:
-    K=A:GOTO ENV_GET
-    ENV_GET_RETURN:
+    B$=S$(Z%(A+1)):CALL ENV_GET
+    IF R3=0 THEN R=-1:ER=-1:E$="'"+B$+"' not found":GOTO EVAL_AST_RETURN
+    GOSUB INC_REF_R
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/stepA_mal.in.bas

@@ -138,12 +138,13 @@ SUB MACROEXPAND
     REM symbol? in first position
     IF (Z%(B)AND 31)<>5 THEN GOTO MACROEXPAND_DONE
     REM defined in environment?
-    K=B:CALL ENV_FIND
-    IF R=-1 THEN GOTO MACROEXPAND_DONE
-    B=R4
+    B$=S$(Z%(B+1)):CALL ENV_GET
+    IF R3=0 THEN GOTO MACROEXPAND_DONE
+    B=R
     REM macro?
     IF (Z%(B)AND 31)<>11 THEN GOTO MACROEXPAND_DONE
 
+    GOSUB INC_REF_R
     F=B:AR=Z%(A+1):CALL APPLY
     A=R
 
@@ -177,8 +178,9 @@ SUB EVAL_AST
   GOTO EVAL_AST_RETURN
 
   EVAL_AST_SYMBOL:
-    K=A:GOTO ENV_GET
-    ENV_GET_RETURN:
+    B$=S$(Z%(A+1)):CALL ENV_GET
+    IF R3=0 THEN R=-1:ER=-1:E$="'"+B$+"' not found":GOTO EVAL_AST_RETURN
+    GOSUB INC_REF_R
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/types.in.bas

@@ -286,10 +286,9 @@ ASSOC1_S:
   AY=K:GOSUB RELEASE: REM map took ownership of key
   RETURN
 
-REM HASHMAP_GET(H, K) -> R
+REM HASHMAP_GET(H, B$) -> R
 REM   - returns R3 with whether we found it or not
 HASHMAP_GET:
-  B$=S$(Z%(K+1)): REM search key string
   R3=0: REM whether found or not (for HASHMAP_CONTAINS)
   R=0
   HASHMAP_GET_LOOP:

impls/basic/variables.txt

@@ -36,7 +36,7 @@ Calling arguments/temporaries:
 A   : common call argument (especially EVAL, EVAL_AST)
 A$  : common call argument (READLINE, reader, string temp, key value)
 B   : common call argument
-B$  : STRING arg (HASHMAP_GET temp), PR_STR_SEQ separator
+B$  : STRING arg for HASHMAP_GET, PR_STR_SEQ separator
     : INIT_CORE_SET_FUNCTION, ENV_SET_S, ASSOC1_S
 C   : common call argument, DO_TCO_FUNCTION temp in DO_APPLY
 E   : environment (EVAL, EVAL_AST)
@@ -60,7 +60,6 @@ P3  : PR_OBJECT, PR_MEMORY_VALUE
 R1  : REP, RE - MAL_READ result temp
 R2  : REP, RE - EVAL result temp
 R3  : HASHMAP_GET, DO_HASH_MAP, DO_KEYS_VALS temp and return value
-R4  : ENV_FIND temp and return value
 R6  : SLICE return value (last element)
 SZ  : size argument to ALLOC
 S1$ : REPLACE needle