git.joshuawise.com / snipe.git / blame
| Commit | Line | Data |
|---|---|---|
| 12aa4087 JW |
1 | (* L1 Compiler |
| 2 | * L1 grammar | |
| 3 | * Author: Kaustuv Chaudhuri <kaustuv+@cs.cmu.edu> | |
| 4 | * Modified: Frank Pfenning <fp@cs.cmu.edu> | |
| 5 | *) | |
| 6 | ||
| 7 | structure A = Ast | |
| 8 | ||
| 9 | (* for simplicity, we only mark expressions, not statements *) | |
| 10 | ||
| 11 | (* mark e with region (left, right) in source file *) | |
| 12 | fun mark (e, (left, right)) = A.Marked (Mark.mark' (e, ParseState.ext (left, right))) | |
| 13 | ||
| 14 | (* create lval from expression; here just an id *) | |
| 15 | (* generates error if not an identifier *) | |
| 16 | fun make_lval (A.Var(id)) ext = id | |
| 17 | | make_lval (A.Marked(marked_exp)) ext = | |
| 18 | make_lval (Mark.data marked_exp) (Mark.ext marked_exp) | |
| 19 | | make_lval _ ext = ( ErrorMsg.error ext "not a variable" ; | |
| 20 | Symbol.bogus ) | |
| 21 | ||
| 22 | (* expand_asnop (exp1, "op=", exp2) region = "exp1 = exp1 op exps" | |
| 23 | * or = "exp1 = exp2" if asnop is "=" | |
| 24 | * generates error if exp1 is an lval (identifier) | |
| 25 | * syntactically expands a compound assignment operator | |
| 26 | *) | |
| 27 | fun expand_asnop (exp1, NONE, exp2) (left, right) = | |
| 28 | A.Assign(make_lval exp1 NONE, exp2) | |
| 29 | | expand_asnop (exp1, SOME(oper), exp2) (left, right) = | |
| 30 | A.Assign(make_lval exp1 NONE, | |
| 31 | mark(A.OpExp(oper, [exp1, exp2]), (left, right))) | |
| 32 | ||
| 33 | %% | |
| 34 | %header (functor L1LrValsFn (structure Token : TOKEN)) | |
| 35 | ||
| 36 | %term | |
| 37 | EOF | |
| 38 | | SEMI | |
| 39 | | INTNUM of Word32.word | |
| 40 | | IDENT of Symbol.symbol | |
| 41 | | RETURN | |
| 42 | | PLUS | MINUS | STAR | SLASH | PERCENT | |
| 43 | | ASSIGN | PLUSEQ | MINUSEQ | STAREQ | SLASHEQ | PERCENTEQ | |
| 44 | | LBRACE | RBRACE | |
| 45 | | LPAREN | RPAREN | |
| 46 | | UNARY | ASNOP (* dummy *) | |
| 47 | ||
| 48 | %nonterm | |
| 49 | program of A.program | |
| 50 | | stms of A.stm list | |
| 51 | | stm of A.stm | |
| 52 | | simp of A.stm | |
| 53 | | return of A.stm | |
| 54 | | exp of A.exp | |
| 55 | | asnop of A.oper option | |
| 56 | ||
| 57 | %verbose (* print summary of errors *) | |
| 58 | %pos int (* positions *) | |
| 59 | %start program | |
| 60 | %eop EOF | |
| 61 | %noshift EOF | |
| 62 | ||
| 63 | %name L1 | |
| 64 | ||
| 65 | %left PLUS MINUS | |
| 66 | %left STAR SLASH PERCENT | |
| 67 | %right UNARY | |
| 68 | %left LPAREN | |
| 69 | ||
| 70 | %% | |
| 71 | ||
| 72 | program : LBRACE stms return RBRACE | |
| 73 | (stms@[return]) | |
| 74 | ||
| 75 | return : RETURN exp SEMI (A.Return exp) | |
| 76 | ||
| 77 | stms : ([]) | |
| 78 | | stm stms (stm :: stms) | |
| 79 | ||
| 80 | stm : simp SEMI (simp) | |
| 81 | simp : exp asnop exp %prec ASNOP | |
| 82 | (expand_asnop (exp1, asnop, exp2) (exp1left, exp2right)) | |
| 83 | ||
| 84 | exp : LPAREN exp RPAREN (exp) | |
| 85 | | INTNUM (mark (A.ConstExp(INTNUM),(INTNUMleft,INTNUMright))) | |
| 86 | | IDENT (mark (A.Var(IDENT), (IDENTleft,IDENTright))) | |
| 87 | | exp PLUS exp (mark (A.OpExp (A.PLUS, [exp1,exp2]), (exp1left,exp2right))) | |
| 88 | | exp MINUS exp (mark (A.OpExp (A.MINUS, [exp1,exp2]), (exp1left,exp2right))) | |
| 89 | | exp STAR exp (mark (A.OpExp (A.TIMES, [exp1,exp2]), (exp1left,exp2right))) | |
| 90 | | exp SLASH exp (mark (A.OpExp (A.DIVIDEDBY, [exp1,exp2]), (exp1left,exp2right))) | |
| 91 | | exp PERCENT exp (mark (A.OpExp (A.MODULO, [exp1,exp2]), (exp1left,exp2right))) | |
| 92 | | MINUS exp %prec UNARY (mark (A.OpExp (A.NEGATIVE, [exp]), (MINUSleft,expright))) | |
| 93 | ||
| 94 | asnop : ASSIGN (NONE) | |
| 95 | | PLUSEQ (SOME(A.PLUS)) | |
| 96 | | MINUSEQ (SOME(A.MINUS)) | |
| 97 | | STAREQ (SOME(A.TIMES)) | |
| 98 | | SLASHEQ (SOME(A.DIVIDEDBY)) | |
| 99 | | PERCENTEQ (SOME(A.MODULO)) |