Support for string literals and a 'write' builtin predicate

Makefile

@@ -1,4 +1,15 @@
-.PHONY: ceptre
+.PHONY: ceptre syn
 
 ceptre:
 	mlton -output ceptre src/sources.mlb
+
+
+syn: src/ceptre.cmlex.sml src/ceptre.cmyacc.sml
+
+%.cmlex.sml : %.cmlex
+	cmlex $< -o $@
+
+%.cmyacc.sml : %.cmyacc
+	cmyacc $< -o $@
+
+

ceptre.vim

@@ -4,18 +4,21 @@ syn clear
 set iskeyword+=\",~,@,!,#-',*-45,47-57,59-90,94-122,\|,^:
 
 syn keyword ceptrePercentKey #mode #interactive #trace #builtin
-syn keyword ceptreType type pred bwd stage context
+syn keyword ceptreType type pred action bwd stage context
 syn match ceptrePunct ":\|\.\|="
 syn match ceptreFVar "\<[A-Z_]\k*\>"  
 syn keyword ceptreSymbol -> <- -o o- *
 syn match ceptreDecl "^\s*[^()A-Z_]\k*\s*:" contains=ceptrePunct
 
+syn match ceptreNumber "0\|[1-9]\d*"
+syn match ceptreEsc "\\."
+syn region ceptreString start="\"" end="\"" contains=ceptreEsc
 
 syn match ceptreCurly "{\|}" contained
 syn match ceptreSquare "\[\|\]" contained
 syn match ceptreBindDecl "[^A-Z_{\[]\k*\s*:" contains=ceptrePunct contained
-syn region ceptrePiBind start="{" end="}" keepend transparent contains=ceptreCurly,ceptrePunct,ceptreFVar,ceptreSymbol,ceptreType,ceptreBindDecl,ceptreComment
-syn region ceptreLamBind start="\[" end="\]" keepend transparent contains=ceptreSquare,ceptrePunct,ceptreFVar,ceptreSymbol,ceptreType,ceptreBindDecl,ceptreComment
+syn region ceptrePiBind start="{" end="}" keepend transparent contains=ceptreCurly,ceptrePunct,ceptreFVar,ceptreSymbol,ceptreType,ceptreBindDecl,ceptreComment,ceptreNumber,ceptreString
+syn region ceptreLamBind start="\[" end="\]" keepend transparent contains=ceptreSquare,ceptrePunct,ceptreFVar,ceptreSymbol,ceptreType,ceptreBindDecl,ceptreComment,ceptreNumber,ceptreString
 
 syn match ceptreParen "(\|)" contained
 syn region ceptreParens start="(" end=")" transparent contains=ALL
@@ -38,6 +41,9 @@ hi link ceptreSymbol            Operator
 hi link ceptreDecl              Identifier
 hi link ceptreBindDecl          ceptreDeclarationFace
 hi link ceptreFVar              Identifier
+hi link ceptreNumber            Number
+hi link ceptreEsc               SpecialChar
+hi link ceptreString            String
 
 " Indentation
 setlocal foldmethod=syntax

examples/write.cep

@@ -0,0 +1,32 @@
+nat : type.   #builtin NAT nat.
+z : nat.      #builtin NAT_ZERO z.
+s nat : nat.  #builtin NAT_SUCC s.
+
+plus nat nat nat : bwd.
+plus/z : plus z N N.
+plus/s : plus (s N) M (s P) <- plus N M P.
+
+go nat nat : pred.
+
+str : type. #builtin STRING str.
+write/str str : action. #builtin WRITE write/str.
+write/nat nat : action. #builtin WRITE write/nat.
+write/res str nat str nat str nat str : action. #builtin WRITE write/res.
+
+stage rules {
+  name: go N M * plus N M P -o
+
+      write/res "The result of " N " + " M " is " P ".\n"
+
+    * write/str "THe result of "
+    * write/nat N
+    * write/str " + "
+    * write/nat M
+    * write/str " is "
+    * write/nat P
+    * write/str ".\n".
+}
+
+context init = { go 99 12 }.
+
+#trace _ rules init.

src/ceptre.cmlex

@@ -12,6 +12,10 @@ regexp ident = (seq id_start (* id_cont))
 regexp ws = (+ white)
 regexp number = (| '0 (seq posdigit (* digit)))
 
+set nonesc = (~ (| '\ '"))
+regexp esc = (seq '\ notnewln)
+regexp string = (seq '" (* (| nonesc esc)) '")
+
 function lexmain: t = 
    eos => eof 
    "pred" => pred
@@ -39,6 +43,7 @@ function lexmain: t =
    "o-" => llolli
    "-o" => rlolli
    number => num
+   string => str
    ident => ident
    any => error
    epsilon => error