4 files changed, 44 insertions, 1 deletions
diff --git a/src/sys/include/np/lex.h b/src/sys/include/np/lex.h
index ebd6f32..ba581b7 100644
--- a/src/sys/include/np/lex.h
+++ b/src/sys/include/np/lex.h
@@ -41,6 +41,7 @@ struct np_work;
 #define TOKEN_BEGIN "begin"
 #define TOKEN_PROC "proc"
 #define TOKEN_END "end"
+#define TOKEN_RETURN "return"
 
 /* Types */
 #define TOKEN_U8    "u8"
@@ -93,6 +94,7 @@ typedef enum {
     TT_BEGIN,           /* 'begin' */
     TT_PROC,            /* 'proc' */
     TT_END,             /* 'end' */
+    TT_RETURN,          /* 'return' */
 } tt_t;
 
 typedef uint64_t tokval_t;
diff --git a/src/sys/include/np/piir.h b/src/sys/include/np/piir.h
index d108776..5625409 100644
--- a/src/sys/include/np/piir.h
+++ b/src/sys/include/np/piir.h
@@ -56,6 +56,7 @@ typedef int8_t md_byte_t;
 #define PIIR_LOAD_R32 0x03  /* Load 32-bit register */
 #define PIIR_LOAD_R64 0x04  /* Load 64-bit register */
 #define PIIR_RET_NIL  0x05  /* Return nothing */
+#define PIIR_RET_NUM  0x06  /* Return a number */
 
 /*
  * Represents the PIIR virtual machine for storing
diff --git a/src/sys/np/core/np_lex.c b/src/sys/np/core/np_lex.c
index 389f1e2..222feba 100644
--- a/src/sys/np/core/np_lex.c
+++ b/src/sys/np/core/np_lex.c
@@ -144,6 +144,11 @@ static int
 lex_cmptok(char *tokstr, struct lex_token *res)
 {
     switch (*tokstr) {
+    case 'r':
+        if (strcmp(tokstr, TOKEN_RETURN) == 0) {
+            res->token = TT_RETURN;
+        }
+        return 0;
     case 'b':
         if (strcmp(tokstr, TOKEN_BEGIN) == 0) {
             res->token = TT_BEGIN;
diff --git a/src/sys/np/core/np_parse.c b/src/sys/np/core/np_parse.c
index 4119d8b..b7b854b 100644
--- a/src/sys/np/core/np_parse.c
+++ b/src/sys/np/core/np_parse.c
@@ -84,7 +84,8 @@ static const char *stoktab[] = {
     /* Keywords */
     [TT_BEGIN]  = "<TT_BEGIN>",
     [TT_PROC]   = "<TT_PROC>",
-    [TT_END]    = "<TT_END>"
+    [TT_END]    = "<TT_END>",
+    [TT_RETURN] = "<TT_RETURN>"
 };
 
 /*
@@ -173,6 +174,35 @@ parse_type(struct np_work *work, struct lex_token *tok)
 }
 
 /*
+ * Parse a return statement
+ *
+ * @work: Input work
+ * @tok: Current token
+ *
+ * Returns zero on success
+ */
+static int
+parse_return(struct np_work *work, struct lex_token *tok)
+{
+    tt_t tt;
+
+    /*
+     * For now we'll only accept numbers as return values
+     * so we must see one after the return statement
+     */
+    tt = parse_expect(work, "return", TT_NUMBER, tok);
+    if (tt == TT_NONE) {
+        return -1;
+    }
+
+#define PIIR_PUSH(BYTE) piir_push(work->piir_stack, (BYTE))
+    PIIR_PUSH(PIIR_RET_NUM);
+    PIIR_PUSH(tok->val);
+#undef PIIR_PUSH
+    return 0;
+}
+
+/*
  * Parse a procedure / function
  *
  * @work: Input work
@@ -311,6 +341,11 @@ parse_token(struct np_work *work, struct lex_token *tok)
         /* XXX: NOP for testing */
         PIIR_PUSH(PIIR_NOP);
         break;
+    case TT_RETURN:
+        if ((error = parse_return(work, tok)) != 0) {
+            return -1;
+        }
+        break;
     }
 #undef PIIR_PUSH
     return 0;