basic: merge env_find into env_get

Author: asarhaddon

impls/basic/env.in.bas

@@ -63,27 +63,16 @@ 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, K) -> R
+REM R3 is either 0 (missing key) or 1, then R is the increfed value.
+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 INC_REF_R
     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

@@ -29,8 +29,7 @@ SUB EVAL_AST
 
   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
+    IF R3=0 THEN ER=-1:E$="'"+S$(Z%(A+1))+"' not found" ELSE GOSUB INC_REF_R
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/step3_env.in.bas

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

impls/basic/step4_if_fn_do.in.bas

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

impls/basic/step5_tco.in.bas

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

impls/basic/step6_file.in.bas

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

impls/basic/step7_quote.in.bas

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

impls/basic/step8_macros.in.bas

@@ -138,9 +138,9 @@ 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
+    K=B:GOSUB ENV_GET
+    IF R3=0 THEN GOTO MACROEXPAND_DONE
+    B=R
     REM macro?
     IF (Z%(B)AND 31)<>11 THEN GOTO MACROEXPAND_DONE
 
@@ -177,8 +177,8 @@ SUB EVAL_AST
   GOTO EVAL_AST_RETURN
 
   EVAL_AST_SYMBOL:
-    K=A:GOTO ENV_GET
-    ENV_GET_RETURN:
+    K=A:GOSUB ENV_GET
+    IF R3=0 THEN ER=-1:E$="'"+S$(Z%(A+1))+"' not found"
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/step9_try.in.bas

@@ -138,9 +138,9 @@ 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
+    K=B:GOSUB ENV_GET
+    IF R3=0 THEN GOTO MACROEXPAND_DONE
+    B=R
     REM macro?
     IF (Z%(B)AND 31)<>11 THEN GOTO MACROEXPAND_DONE
 
@@ -177,8 +177,8 @@ SUB EVAL_AST
   GOTO EVAL_AST_RETURN
 
   EVAL_AST_SYMBOL:
-    K=A:GOTO ENV_GET
-    ENV_GET_RETURN:
+    K=A:GOSUB ENV_GET
+    IF R3=0 THEN ER=-1:E$="'"+S$(Z%(A+1))+"' not found"
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/stepA_mal.in.bas

@@ -138,9 +138,9 @@ 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
+    K=B:GOSUB ENV_GET
+    IF R3=0 THEN GOTO MACROEXPAND_DONE
+    B=R
     REM macro?
     IF (Z%(B)AND 31)<>11 THEN GOTO MACROEXPAND_DONE
 
@@ -177,8 +177,8 @@ SUB EVAL_AST
   GOTO EVAL_AST_RETURN
 
   EVAL_AST_SYMBOL:
-    K=A:GOTO ENV_GET
-    ENV_GET_RETURN:
+    K=A:GOSUB ENV_GET
+    IF R3=0 THEN ER=-1:E$="'"+S$(Z%(A+1))+"' not found"
     GOTO EVAL_AST_RETURN
 
   EVAL_AST_SEQ:

impls/basic/variables.txt

@@ -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