All: add keywords.

Also, fix nth and count to match cloure.

4 files changed, 87 insertions, 13 deletions

diff --git a/ps/core.ps b/ps/core.ps
index 191e5c3..52c9b05 100644
--- a/ps/core.ps
+++ b/ps/core.ps
@@ -87,8 +87,8 @@ end } def
     _list_from_array
 end } def
 
-% [listA listB] -> concat -> [listA... listB...]
-/concat { % replaces matric concat
+% [listA listB] -> do_concat -> [listA... listB...]
+/do_concat {
     dup _count 0 eq { %if just concat
         pop 0 _list
     }{ dup _count 1 eq { %elseif concat of single item
@@ -102,6 +102,15 @@ end } def
     } ifelse } ifelse
 } def
 
+% [obj] -> do_count -> number
+/do_count {
+    0 _nth dup _nil? {
+        pop 0
+    }{
+        _count
+    } ifelse
+} def
+
 % [obj ...] -> first -> obj
 /first {
     0 _nth _first
@@ -220,7 +229,10 @@ end } def
     (nil?)    { 0 _nth _nil? }
     (true?)   { 0 _nth _true? }
     (false?)  { 0 _nth _false? }
+    (symbol)  { 0 _nth _symbol }
     (symbol?) { 0 _nth _symbol? }
+    (keyword) { 0 _nth _keyword }
+    (keyword?) { 0 _nth _keyword? }
 
     (pr-str)  { /data get ( ) true _pr_str_args }
     (str)     { /data get () false _pr_str_args }
@@ -254,12 +266,12 @@ end } def
 
     (sequential?) { 0 _nth _sequential? }
     (cons)    { cons }
-    (concat)  { concat }
+    (concat)  { do_concat }
     (nth)     { dup 0 _nth exch 1 _nth _nth }
     (first)   { first }
     (rest)    { rest }
     (empty?)  { 0 _nth _count 0 eq }
-    (count)   { 0 _nth _count }
+    (count)   { do_count }
     (conj)    { conj }
     (apply)   { apply }
     (map)     { map }
diff --git a/ps/printer.ps b/ps/printer.ps
index 3062e2d..52d6c1e 100644
--- a/ps/printer.ps
+++ b/ps/printer.ps
@@ -45,13 +45,24 @@
         /slen obj 10 add log ceiling cvi def
         obj 10 slen string cvrs
     }{ /stringtype obj type eq { % if string
-        print_readably {
-            (")
-            obj (\\) (\\\\) replace
-                (") (\\") replace
-            (") concatenate concatenate
-        }{
-            obj
+        obj length 0 gt { % if string length > 0
+            obj 0 get 127 eq { %if starts with 0x7f (keyword)
+                obj dup length string copy
+                dup 0 58 put % 58 is ':'
+            }{ print_readably {
+                (")
+                obj (\\) (\\\\) replace
+                    (") (\\") replace
+                (") concatenate concatenate
+            }{
+                obj
+            } ifelse } ifelse
+        }{ % else empty string
+            print_readably {
+                ("")
+            }{
+                obj
+            } ifelse
         } ifelse
     }{ null obj eq { % if nil
         (nil)
diff --git a/ps/reader.ps b/ps/reader.ps
index f1f63f6..4b268c0 100644
--- a/ps/reader.ps
+++ b/ps/reader.ps
@@ -52,6 +52,32 @@ end } def
 end } def
 
 
+% read_keyword: read a single keyword from string/idx
+% string idx -> read_keyword -> name string new_idx
+/read_keyword { 5 dict begin
+    %(in read_keyword\n) print
+    /idx exch def
+    /str exch def
+    /start idx def
+    /cnt 0 def
+    { % loop
+        idx str length ge { exit } if % EOF, break loop
+        /ch str idx 1 getinterval def
+        token_delim ch search { % if token delimeter
+            pop pop pop exit
+        }{ % else not a delim
+            pop
+            /cnt cnt 1 add def
+        } ifelse
+        /idx idx 1 add def % increment idx
+    } loop
+
+    str start cnt getinterval % the matched keyword string
+    dup 0 127 put % TODO: something like (\x029e) would be better
+    str idx % return: keyword string new_idx
+end } def
+
+
 % read_string: read a single string from string/idx
 % string idx -> read_string -> new_string string new_idx
 /read_string { 5 dict begin
@@ -94,8 +120,10 @@ end } def
         %ch 48 ge ch 57 le and 45 ch eq or { %if number
         ch 48 ge ch 57 le and { %if number
             str idx read_number
-        }{ ch 34 eq { %elseif double-quote
+        }{ ch 34 eq { %elseif double-quote (string)
             str idx read_string
+        }{ ch 58 eq { %elseif colon (keyword)
+            str idx read_keyword
         }{
             str idx read_symbol
             /idx exch def pop
@@ -108,7 +136,7 @@ end } def
             }{ %else
                 str idx % return the original symbol/name
             } ifelse } ifelse } ifelse
-        } ifelse } ifelse
+        } ifelse } ifelse } ifelse
     }ifelse
 
     % return: atom string new_idx
diff --git a/ps/types.ps b/ps/types.ps
index 82be9c2..1f6903e 100644
--- a/ps/types.ps
+++ b/ps/types.ps
@@ -173,11 +173,34 @@ end } def
 
 % Symbols
 
+/_symbol {
+    dup length string copy cvn
+} def
+
 /_symbol? {
     type /nametype eq
 } def
 
 
+% Keywords
+
+/_keyword { 1 dict begin
+    /str exch def
+    str length 1 add string % str2
+    dup 1 str putinterval
+    dup 0 127 put % TODO: something like (\x029e) would be better
+end } def
+
+/_keyword? {
+    dup type /stringtype eq {
+        0 get 127 eq
+    }{
+        false
+    } ifelse
+} def
+
+
+
 % Functions
 
 % block -> _function -> boxed_function