ref: c1cebeee3da60bac9fdde3d8b2caac29c27ef912
parent: c56f21d2819ed6c69215124364527b5f9fba371c
author: rodri <rgl@antares-labs.eu>
date: Mon Mar 31 08:15:47 EDT 2025
forgot to add main.c
--- /dev/null
+++ b/main.c
@@ -1,0 +1,165 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <geometry.h>
+#include "dat.h"
+#include "fns.h"
+
+int debuglexer;
+
+/*
+ * decl : type ;
+ * | type id
+ * | type id , decl
+ * | type id , ids
+ * ids : id
+ * | id , ids
+ */
+static int
+parsedecl(Lexer *l)
+{+ Var v;
+ int vt;
+
+ vt = vartype(l->tok.type);
+
+ if(gotany(l, ';', 0))
+ return 0;
+ids:
+ if(!expect(l, TID))
+ return -1;
+ if(getsym(l->tok.s) != nil){+ werrstr("'%s' already declared", l->tok.s);+ return -1;
+ }
+
+ v.type = vt;
+ memset(v.val, 0, sizeof(v.val));
+ if(declsym(l->tok.s, SYMVAR, v) == nil){+ werrstr("declsym: %r");+ return -1;
+ }
+ free(l->tok.s);
+
+ if(gotany(l, ',', 0)){+ if(gottype(l))
+ return parsedecl(l);
+ goto ids;
+ }
+ return 0;
+}
+
+static int
+parseexpr(Lexer *l)
+{+ Symbol *s1, *s2;
+ Op op;
+ double n1, n2;
+
+ s1 = s2 = nil;
+
+ if(l->tok.type == TNUM)
+ n1 = l->tok.v;
+ else{+ s1 = getsym(l->tok.s);
+ if(s1 == nil){+ werrstr("'%s' undefined", l->tok.s);+ return -1;
+ }
+ free(l->tok.s);
+ }
+
+ if(!expectany(l, '+', '-', '*', '/', L'·', L'×', 0))
+ return -1;
+ op.type = optype(l->tok.type);
+ op.tok = l->tok.type;
+
+ if(!expectany(l, TNUM, TID, 0))
+ return -1;
+ if(l->tok.type == TNUM)
+ n2 = l->tok.v;
+ else{+ s2 = getsym(l->tok.s);
+ if(s2 == nil){+ werrstr("'%s' undefined", l->tok.s);+ return -1;
+ }
+ free(l->tok.s);
+ }
+ if(s1 != nil)
+ fprint(2, "%s", s1->name);
+ else
+ fprint(2, "%g", n1);
+ fprint(2, " %C", op.tok);
+ if(s2 != nil)
+ fprint(2, " %s\n", s2->name);
+ else
+ fprint(2, " %g\n", n2);
+ return 0;
+}
+
+/*
+ * stmt : stmts ;
+ * stmts: decl
+ */
+static int
+parsestmt(Lexer *l)
+{+ if(gottype(l))
+ if(parsedecl(l) < 0)
+ sysfatal("parsedecl: %r");+ if(gotany(l, TNUM, TID, 0))
+ if(parseexpr(l) < 0)
+ sysfatal("parseexpr: %r");+ if(!expect(l, ';'))
+ return -1;
+ return 0;
+}
+
+static int
+parse(Lexer *l)
+{+ for(;;){+ if(peek(l) < 0)
+ sysfatal("error: %r");+ else if(l->peektok.type == TEOF)
+ break;
+ if(parsestmt(l) < 0)
+ sysfatal("parsestmt: %r");+ }
+ printsymtab();
+ return 0;
+}
+
+static void
+usage(void)
+{+ fprint(2, "usage: %s\n", argv0);
+ exits("usage");+}
+
+void
+main(int argc, char *argv[])
+{+ Lexer *l;
+
+ debuglexer = 0;
+ ARGBEGIN{+ case 'd': debuglexer++; break;
+ default: usage();
+ }ARGEND;
+ if(argc != 0)
+ usage();
+
+ l = emalloc(sizeof(Lexer));
+ l->in = Bfdopen(0, OREAD);
+ if(l->in == nil)
+ sysfatal("Bfdopen: %r");+ l->ln.line = 1;
+
+ parse(l);
+
+ Bterm(l->in);
+ free(l);
+ exits(nil);
+}