C-val Compiler

Lexical Spec

• LBRACK [
• RBRACK ]
• LCURLY {
• RCURLY }
• LPAREN (
• RPAREN )
• ID [any character without whitespace]+
• SEMI ;
• COMMA ,
• ARROW ->
• STAR *
• ANDREF &
• DOLLAR $
• COMMENT //
• NUM [0-9]*
• VAL
• STRING "{any}"

Syntax Spec

program     := defn*

defn        := VAL type ID ;
             | VAL type ID expr ;

type        := ID | type STAR
             | LBRACK RBRACK | LBRACK type RBRACK
             | LBRACK type* ARROW type? RBRACK

expr        := atom atom*

atom        := ID
             | NUM
             | STR
             | lambda
             | compound
             | STAR
             | ANDREF

stmt        := defn
             | expr ;        // expr statement
             | return expr ; // return statement
             | DOLLAR ID expr ;   // assignment statement
             | if expr compound ;               // if statement
             | if expr compound else compound ; // if-else statement

param_list  := LPAREN (type ID)* RPAREN

lambda      := param_list compound

compound    := LCURLY (stmt)* expr? RCURLY