gh-193: Make DEL use STR.

Closes #193.

Author: python-processing-unit

docs/SPECIFICATION.html

@@ -96,7 +96,7 @@
 
 The first assignment to a symbol MUST use a typed form such as `TYPE name = expression`, with one or more spaces between the type and name and optional spaces around `=`. Subsequent assignments MAY omit the type annotation, but the symbol's type MUST remain unchanged for the lifetime of that name, including after deletion and re-assignment.
 
-Assignments to undeclared identifiers without a type annotation MUST raise a runtime error. A binding MUST remain allocated until it is deleted with `DEL(name)`.
+Assignments to undeclared identifiers without a type annotation MUST raise a runtime error. A binding MUST remain allocated until it is deleted with `DEL("name")`.
 
 The built-in `ASSIGN(target, expression)` MUST provide expression-position assignment. The `target` MAY be a plain identifier or an indexed target. If the identifier does not yet exist, the typed form `ASSIGN(TYPE name, expression)` MUST be used, and that typed form is valid only for plain identifiers.
 
@@ -695,9 +695,9 @@
 
 #### 9.1.1 Symbol and type operators
 
-- `BOOL DEL(SYMBOL name)` = MUST delete the readable runtime binding designated by `name`. Deletion MUST preserve the symbol's recorded static type as defined in [5.1](#51-declarations-bindings-and-lifetime). Deleting an undeclared, never-assigned, or already-deleted symbol MUST raise a runtime error. Deleting a frozen or permanently frozen binding MUST raise a runtime error. On success, `DEL` MUST return `FALSE`.
+- `BOOL DEL(STR target)` = MUST evaluate `target`, require the result to be a `STR`, and parse that string as exactly one Prefix target expression. The parsed target MUST be either a plain identifier such as `name` or an indexed identifier such as `name<key>` or `name<k1, k2, ...>`. If the parsed target is a plain identifier, `DEL` MUST delete the readable runtime binding designated by that identifier. Deletion MUST preserve the symbol's recorded static type as defined in [5.1](#51-declarations-bindings-and-lifetime). Deleting an undeclared, never-assigned, or already-deleted symbol MUST raise a runtime error. Deleting a frozen or permanently frozen binding MUST raise a runtime error.
 
-- `BOOL DEL(target<key>)` or `BOOL DEL(target<k1, k2, ...>)` = MUST delete the map entry identified by the final key in the chain of map indices. `target` MUST resolve to a `MAP` value and all intermediate lookups MUST resolve to nested `MAP` values; indexing a non-`MAP` MUST raise a runtime error. If an intermediate key does not exist, the operation MUST be a no-op. After deletion the modified map MUST be written back to the environment. `DEL` in indexed form MUST return `FALSE` whether it deleted an entry or completed as a no-op.
+- When the parsed `DEL` target is indexed, the base target MUST resolve to a `MAP` value and all intermediate lookups MUST resolve to nested `MAP` values; indexing a non-`MAP` MUST raise a runtime error. The map entry identified by the final key in the chain MUST be deleted. If an intermediate key does not exist, the operation MUST be a no-op. After deletion the modified map MUST be written back to the environment. `DEL` MUST return `FALSE` on success, including indexed no-op cases.
 
 - `ANY ASSIGN(target, ANY value)` = MUST evaluate `value`, assign it to `target`, and return the assigned value. `target` MAY be a plain identifier, a tensor indexed target, or a map indexed target. If a plain identifier has not yet been declared, the typed form `ASSIGN(TYPE name, value)` MUST be used. The typed form MUST NOT be used with indexed targets.
 

lib/std/image/init.pre

@@ -131,6 +131,6 @@ FUNC BOOL SHOW(TNS img){
     ! ShellExecuteW(hwnd, operation, file, params, dir, showcmd)
     ! Use NULL hwnd (0), operation "open", empty params and dir, showcmd=1
     win32.WIN_CALL("shell32", "ShellExecuteW", "PSSSSI", "P", 0d0, "open", img_path, "", "", 0d1)
-    DEL(img_path)
+    DEL("img_path")
     RETURN(FALSE)
 }

lib/std/path.pre

@@ -15,13 +15,14 @@ FUNC STR BASEPATH(STR path){ ! returns directory portion of path
         RETURN("")
     }
     STR dir = REPLACE(npath, JOIN("/", base), "")
+    DEL("npath")
     POP("dir")
 }
 
 FUNC STR BASENAME(STR path){ ! returns filename portion of path
     TNS tpath = SPLIT(NORMALIZE_PATH(path), "/")
     STR basename = tpath[MAX(TLEN(tpath, 0d1), 0d1)]
-    DEL(tpath)
+    DEL("tpath")
     POP("basename")
 }
 
@@ -32,15 +33,15 @@ FUNC TNS SPLITEXT(STR path){ ! returns [name without ext, ext]
     TNS parts = SPLIT(base, ".")
     ! If there is no dot, return the path unchanged and empty ext
     IF(EQ(TLEN(parts, 0d1), 0d1)){
-        DEL(base)
+        DEL("base")
         TNS result = [npath, ""]
         POP("result")
     }
     ! Extension is the last segment (1-based indexing)
     STR ext = parts[ TLEN(parts, 0d1) ]
     ! Name is base without the final "." + ext suffix
     STR name = REPLACE(base, JOIN(".", ext), "")
-    DEL(parts)
+    DEL("parts")
     STR delex = ""
     IF(EQ(dir, "")){
         delex = name
@@ -51,8 +52,8 @@ FUNC TNS SPLITEXT(STR path){ ! returns [name without ext, ext]
             delex = JOIN(dir, name)
         }
     }
-    DEL(dir)
-    DEL(name)
+    DEL("dir")
+    DEL("name")
     TNS result = [delex, ext]
     POP("result")
 }
@@ -76,7 +77,7 @@ FUNC STR TEMPFILE(STR local_path){
         STR temp = "/tmp/"
     }
     STR final_path = JOIN(temp, local_path)
-    DEL(temp)
+    DEL("temp")
     POP("final_path")
 }
 

lib/std/waveforms.pre

@@ -19,7 +19,7 @@ FUNC TNS SQUARE(INT freq, INT ms, INT amp, INT sr){
     INT frames = /(*(sr, ms), MS_DEN)
     TNS shape = [frames]
     TNS out = TNS(shape, 0d0)
-    DEL(shape)
+    DEL("shape")
     INT period = CDIV(sr, freq)
     IF(LTE(period, 0d0)){ RETURN(out) }
     INT half = /(period, 0d2)
@@ -29,11 +29,11 @@ FUNC TNS SQUARE(INT freq, INT ms, INT amp, INT sr){
         IF(GTE(pos, half)){ v = NEG(amp) }
         out[idx] = AUDIO_CLAMP(v)
     }
-    DEL(frames)
-    DEL(period)
-    DEL(half)
-    DEL(pos)
-    DEL(v)
+    DEL("frames")
+    DEL("period")
+    DEL("half")
+    DEL("pos")
+    DEL("v")
     RETURN(out)
 }
 
@@ -44,7 +44,7 @@ FUNC TNS SAWTOOTH(INT freq, INT ms, INT amp, INT sr){
     INT frames = /(*(sr, ms), MS_DEN)
     TNS shape = [frames]
     TNS out = TNS(shape, 0d0)
-    DEL(shape)
+    DEL("shape")
     INT period = CDIV(sr, freq)
     IF(LTE(period, 0d0)){ RETURN(out) }
     PARFOR(idx, frames){
@@ -54,12 +54,12 @@ FUNC TNS SAWTOOTH(INT freq, INT ms, INT amp, INT sr){
         INT v = -(tmp, amp)
         out[idx] = AUDIO_CLAMP(v)
     }
-    DEL(frames)
-    DEL(period)
-    DEL(pos)
-    DEL(num)
-    DEL(tmp)
-    DEL(v)
+    DEL("frames")
+    DEL("period")
+    DEL("pos")
+    DEL("num")
+    DEL("tmp")
+    DEL("v")
     RETURN(out)
 }
 
@@ -70,7 +70,7 @@ FUNC TNS TRIANGLE(INT freq, INT ms, INT amp, INT sr){
     INT frames = /(*(sr, ms), MS_DEN)
     TNS shape = [frames]
     TNS out = TNS(shape, 0d0)
-    DEL(shape)
+    DEL("shape")
     INT period = CDIV(sr, freq)
     IF(LTE(period, 0d0)){ RETURN(out) }
     INT half = /(period, 0d2)
@@ -89,14 +89,14 @@ FUNC TNS TRIANGLE(INT freq, INT ms, INT amp, INT sr){
         }
         out[idx] = AUDIO_CLAMP(v)
     }
-    DEL(frames)
-    DEL(period)
-    DEL(half)
-    DEL(pos)
-    DEL(v)
-    DEL(num)
-    DEL(tmp)
-    DEL(t)
+    DEL("frames")
+    DEL("period")
+    DEL("half")
+    DEL("pos")
+    DEL("v")
+    DEL("num")
+    DEL("tmp")
+    DEL("t")
     RETURN(out)
 }
 
@@ -108,7 +108,7 @@ FUNC TNS SINE(INT freq, INT ms, INT amp, INT sr){
     TNS shape = [frames]
     TNS base = SAWTOOTH(freq, ms, amp, sr)
     TNS out = TNS(shape, 0d0)
-    DEL(shape)
+    DEL("shape")
     PARFOR(idx, frames){
         INT previ = idx
         IF(GT(idx, 0d1)){ previ = -(idx, 0d1) }
@@ -121,13 +121,13 @@ FUNC TNS SINE(INT freq, INT ms, INT amp, INT sr){
         INT v = /(sum, 0d3)
         out[idx] = AUDIO_CLAMP(v)
     }
-    DEL(frames)
-    DEL(previ)
-    DEL(nexti)
-    DEL(a)
-    DEL(b)
-    DEL(c)
-    DEL(sum)
+    DEL("frames")
+    DEL("previ")
+    DEL("nexti")
+    DEL("a")
+    DEL("b")
+    DEL("c")
+    DEL("sum")
     RETURN(out)
 }
 
@@ -140,7 +140,7 @@ FUNC TNS PULSE(INT freq, INT ms, INT amp, INT sr, INT duty){
     INT frames = /(*(sr, ms), MS_DEN)
     TNS shape = [frames]
     TNS out = TNS(shape, 0d0)
-    DEL(shape)
+    DEL("shape")
     INT period = CDIV(sr, freq)
     IF(LTE(period, 0d0)){ RETURN(out) }
     INT thresh = /(*(period, duty), 0d100)
@@ -150,11 +150,11 @@ FUNC TNS PULSE(INT freq, INT ms, INT amp, INT sr, INT duty){
         IF(GTE(pos, thresh)){ v = NEG(amp) }
         out[idx] = AUDIO_CLAMP(v)
     }
-    DEL(frames)
-    DEL(period)
-    DEL(thresh)
-    DEL(pos)
-    DEL(v)
+    DEL("frames")
+    DEL("period")
+    DEL("thresh")
+    DEL("pos")
+    DEL("v")
     RETURN(out)
 }
 
@@ -224,12 +224,12 @@ FUNC TNS ENVELOPE_ADSR( ^
         }
         out[idx] = AUDIO_CLAMP(v)
     }
-    DEL(slen)
-    DEL(frames)
-    DEL(a)
-    DEL(d)
-    DEL(r)
-    DEL(s_len)
+    DEL("slen")
+    DEL("frames")
+    DEL("a")
+    DEL("d")
+    DEL("r")
+    DEL("s_len")
     RETURN(out)
 }
 
@@ -260,14 +260,14 @@ FUNC TNS LOWPASS(TNS inp, INT cutoff, INT sr){
         IF(GTE(count, 0d1)){ avg = /(sum, count) }
         out[idx] = AUDIO_CLAMP(avg)
     }
-    DEL(slen)
-    DEL(frames)
-    DEL(period)
-    DEL(start)
-    DEL(j)
-    DEL(sum)
-    DEL(count)
-    DEL(avg)
+    DEL("slen")
+    DEL("frames")
+    DEL("period")
+    DEL("start")
+    DEL("j")
+    DEL("sum")
+    DEL("count")
+    DEL("avg")
     RETURN(out)
 }
 
@@ -285,8 +285,8 @@ FUNC TNS HIGHPASS(TNS inp, INT cutoff, INT sr){
         INT b = low[i1]
         out[i1] = AUDIO_CLAMP(-(a, b))
     }
-    DEL(slen)
-    DEL(frames)
-    DEL(low)
+    DEL("slen")
+    DEL("frames")
+    DEL("low")
     RETURN(out)
 }