Extend S" C" and ." so they can be interpreted.

Max length of strings made with S" and ." increased from 255 to 65535 characters.
Saves 1 byte per usage when cross compiling.

Author: Molorius

pkg/forth/builtin/02_core.f

@@ -227,9 +227,22 @@
     COMPILE, \ and compile it!
 ; IMMEDIATE
 : COUNT ( c-addr -- c-addr+1 n ) DUP CHAR+ SWAP C@ ;
-: STRING" '"' WORD ; \ read a string and put it on the stack
-: C" STRING" POSTPONE LITERAL ; IMMEDIATE
-: S" STRING" COUNT SWAP POSTPONE LITERAL POSTPONE LITERAL ; IMMEDIATE
+: STRING" '"' WORD ; ( -- c-addr ) \ read a string and put it on the stack as a counted string
+: LSTRING" '"' LWORD ; ( -- addr u ) \ read a string and put it on the stack as a string and length
+: C" \ this is an extended C" to allow it to run while interpreting
+    STRING" \ always parse the counted string
+    STATE @ IF \ but if we're compiling,
+        POSTPONE LITERAL \ compile the output
+    THEN
+; IMMEDIATE
+
+: S" \ this is the extended mechanics of S" to allow it to run while interpreting
+    LSTRING" \ always parse the string
+    STATE @ IF \ but if we're compiling,
+        SWAP POSTPONE LITERAL POSTPONE LITERAL \ compile the output
+    THEN
+; IMMEDIATE
+
 : [CHAR]
     BL WORD \ get the next word
     COUNT DROP \ get the address of the first letter

pkg/forth/builtin/10_print.f

@@ -56,7 +56,15 @@
     DROP \ remove c-addr
 ;
 
-: ." POSTPONE S" POSTPONE TYPE ; IMMEDIATE
+\ Can be used to print a string while interpreting or compiling.
+: ."
+    POSTPONE S"
+    STATE @ IF
+        POSTPONE TYPE
+    ELSE
+        TYPE
+    THEN
+; IMMEDIATE
 
 \ set EMIT to the system printchar by default
 ' ESP.PRINTCHAR IS EMIT

pkg/forth/primitive.go

@@ -87,7 +87,7 @@ func PrimitiveSetup(vm *VirtualMachine) error {
 			},
 		},
 		{
-			name: "WORD",
+			name: "WORD", // returns a counted string
 			goFunc: func(vm *VirtualMachine, entry *DictionaryEntry) error {
 				n, err := vm.Stack.PopNumber()
 				if err != nil {
@@ -98,7 +98,8 @@ func PrimitiveSetup(vm *VirtualMachine) error {
 					return JoinEntryError(err, entry, "could not parse string")
 				}
 				var de DictionaryEntry
-				cells, err := bytesToCells(str, true)
+				counted := true
+				cells, err := bytesToCells(str, counted)
 				if err != nil {
 					return JoinEntryError(err, entry, "could not convert bytes to cells")
 				}
@@ -119,6 +120,44 @@ func PrimitiveSetup(vm *VirtualMachine) error {
 				return nil
 			},
 		},
+		{
+			name: "LWORD", // returns a string and length
+			goFunc: func(vm *VirtualMachine, entry *DictionaryEntry) error {
+				n, err := vm.Stack.PopNumber()
+				if err != nil {
+					return JoinEntryError(err, entry, "could not pop delimiter")
+				}
+				str, err := vm.ParseArea.Word(byte(n))
+				if err != nil {
+					return JoinEntryError(err, entry, "could not parse string")
+				}
+				var de DictionaryEntry
+				counted := false
+				cells, err := bytesToCells(str, counted)
+				if err != nil {
+					return JoinEntryError(err, entry, "could not convert bytes to cells")
+				}
+				w := WordForth{cells, &de}
+				de = DictionaryEntry{
+					Word: &w,
+					Flag: Flag{Data: true},
+				}
+				c := CellAddress{
+					Entry:     &de,
+					Offset:    0,
+					UpperByte: false,
+				}
+				err = vm.Stack.Push(c)
+				if err != nil {
+					return JoinEntryError(err, entry, "could not push address")
+				}
+				err = vm.Stack.Push(CellNumber{uint16(len(str))})
+				if err != nil {
+					return JoinEntryError(err, entry, "could not push length")
+				}
+				return nil
+			},
+		},
 		{
 			name: "--CREATE-FORTH",
 			goFunc: func(vm *VirtualMachine, entry *DictionaryEntry) error {

pkg/forth/suite_test.go

@@ -366,7 +366,17 @@ func TestSuite(t *testing.T) {
 				T{ 1S 1ST !  1ST @    -> 1S  }T    \ CAN STORE CELL-WIDE VALUE
 			`,
 		},
-		// C"
+		{
+			name: "C\"",
+			setup: `
+				T{ : cq1 C" 123" ; -> }T
+				T{ : cq2 C" " ;    -> }T
+				T{ cq1 COUNT EVALUATE -> 123 }T
+				T{ cq2 COUNT EVALUATE ->     }T
+				\ This test is nonstandard, C" can be interpreted
+				T{ C" A String"DROP -> }T    \ There is no space between the " and 2DROP
+			`,
+		},
 		// DECIMAL does not have any tests
 		{
 			name: "DEFER",
@@ -1000,14 +1010,15 @@ func TestSuite(t *testing.T) {
 			setup: `
 				T{ : GC4 S" XY" ; ->   }T
 				T{ : GC5 S" A String"2DROP ; -> }T \ There is no space between the " and 2DROP
+				\ This test is from an extended mechanic, S" can be interpreted
+				T{ S" A String"2DROP -> }T    \ There is no space between the " and 2DROP
 			`,
 			code: `
 				T{ GC4 SWAP DROP  -> 2 }T
 				T{ GC4 DROP DUP C@ SWAP CHAR+ C@ -> 58 59 }T
 				T{ GC5 -> }T
 			`,
 		},
-		// S"
 		{
 			name: "S>D",
 			code: `