From 2416a8654e3c1a4b74fcc0379dac5294670a1f46 Mon Sep 17 00:00:00 2001
From: Nicholas Noll <nnoll523@gmail.com>
Date: Tue, 26 Oct 2021 12:35:22 -0700
Subject: feat(rc): keywords now recognized. for and while loop

Prototypes for loops sketched. This required recognizing keywords and
returning from yylex. Debugging/testing will be required.
---
 sys/cmd/rc/var.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 67 insertions(+), 2 deletions(-)

(limited to 'sys/cmd/rc/var.c')

diff --git a/sys/cmd/rc/var.c b/sys/cmd/rc/var.c
index 5e1e90c..3e9635f 100644
--- a/sys/cmd/rc/var.c
+++ b/sys/cmd/rc/var.c
@@ -1,6 +1,19 @@
 #include "rc.h"
+#include "parse.h"
+
+// TODO: string interning
+
+// -----------------------------------------------------------------------
+// globals
+
+struct Keyword 
+{
+    char *name;
+    int   type;
+};
 
 static Var *globals[512];
+static struct Keyword keywords[100]; // sparse map means less hits
 
 // -----------------------------------------------------------------------
 // internals
@@ -111,8 +124,6 @@ bigpath(Var *v)
     ·setvar("path", w, 0);
 }
 
-
-
 // -----------------------------------------------------------------------
 // exports
 
@@ -269,3 +280,57 @@ initpath(void)
     bigpath(v);
 }
 
+#define KEYWORDS \
+    KEYWORD("for",    Tfor) \
+    KEYWORD("in",     Tin) \
+    KEYWORD("while",  Twhile) \
+    KEYWORD("if",     Tif) \
+    KEYWORD("else",   Telse) \
+    KEYWORD("switch", Tswitch) \
+    KEYWORD("case",   Tcase) \
+    KEYWORD("!",      Tbang) \
+    KEYWORD("@",      Tsubshell) \
+    KEYWORD("func",   Tfunc)
+
+void
+initkeywords(void)
+{
+    int i, s, j, h;
+#define KEYWORD(a, b) a,
+    static char *name[]  = { KEYWORDS };
+#undef KEYWORD
+#define KEYWORD(a, b) b,
+    static int type[] = { KEYWORDS };
+#undef KEYWORD
+
+    for(i = 0; i < arrlen(type); i++){
+        h = hash(name[i], arrlen(keywords));
+        for(s=0; s < arrlen(keywords); s++){
+            j = (h + s) % arrlen(keywords);
+            if(!keywords[j].type || strcmp(keywords[j].name, name[i]) == 0){
+                keywords[j].name = name[i];
+                keywords[j].type = type[i];
+                goto nextkeyword;
+            }
+        }
+    nextkeyword:;
+    }
+}
+
+int
+iskeyword(char *word)
+{
+    int i, s, h;
+
+    h = hash(word, arrlen(keywords));
+    for(s = 0; s < arrlen(keywords); s++){
+        i = (h + s) % arrlen(keywords);
+        if(!keywords[i].type)
+            return 0;
+        if(strcmp(keywords[i].name, word) == 0)
+            return keywords[i].type;
+    }
+    return 0;
+}
+
+#undef KEYWORDS
-- 
cgit v1.2.1