Diff: plEarlz.cpp

Revision:

4:b44c27404035

Parent:

3:2bc2b0dce10e

Child:

5:367397a82ddc

--- a/plEarlz.cpp	Wed Sep 19 04:44:07 2012 +0000
+++ b/plEarlz.cpp	Wed Sep 19 05:05:31 2012 +0000
@@ -1,107 +1,165 @@
-#include "mbedconsole.h"
-#include "plEarlz.h"
-#include <stdarg.h>
-//Basically a non-conforming take on Forth, btw.
-
-inline int internal_captureline(void* pBuffer, char const* pFormatString, ...)
-{
-    char*   pStringEnd = (char*)pBuffer + strlen((char*)pBuffer);
-    va_list valist;
-    
-    va_start(valist, pFormatString);
-    
-    return vsprintf(pStringEnd, pFormatString, valist);
-}
-void printheapstats()
-{
-    char buffer[256];
-    __heapstats(internal_captureline, buffer);
-    vputs("Memory info: ");
-    vputs(buffer);
-}
-
-struct pl_word
-{
-
-};
-
-#define MAXSTACK 256
-#define MAXCALLS 64
-#define MAXLINELENGTH 128
-
-int stackpos=0;
-int pl_stack[MAXSTACK];
-
-//int *pl_callstack[MAXCALLS];
-
-enum WordType
-{
-    Unknown,
-    Number,
-    Word,
-    Quote
-};
-
-void execute_word(char *word)
-{
-
-
-}
-
-void parse_line(char *line)
-{
-    int len=strlen(line);
-    char word[16];
-    word[0]=0;
-    int wordpos=0;
-    WordType type=Unknown;
-    for(int i=0;i<len;i++)
-    {
-        char c=line[i];
-        if(is_whitespace(c))
-        {
-            if(word[0]!=0)
-            {
-                execute_word(word);
-                word[0]=0;
-                type=Unknown;
-            }
-        }else if(is_numeric(c)){
-            type=Number;
-            word[wordpos]=c;
-            wordpos++;
-        }else if(is_quote(c)){
-            vputs("This isn't supported yet foo!");
-        }else{
-            type=Word;
-            word[wordpos]=c;
-            wordpos++;
-        }
-    }
-}
-
-
-
-int pl_shell()
-{
-    vputs(">>plEarlz -- A forth-ish shell<<\n");
-    printheapstats();
-    vputs("\n");
-    char *line=(char*)malloc(MAXLINELENGTH);
-    sprintf(line, "Stack Size: %i; Max Recursion Level %i; Loaded WORDs: %i", MAXSTACK, MAXCALLS, 0);
-    vputs(line);
-    sprintf(line, "Max line length: %i", MAXLINELENGTH);
-    vputs(line);
-    char *tmp=(char*)malloc(32); //for constructing words/elements
-    while(1)
-    {
-        vputs("cmd> ");
-        vgetsl(line, MAXLINELENGTH);
-        line[MAXLINELENGTH-1]=0;
-        parse_line(line);
-    
-    }
-    return 0;
-}
-
-
+#include "mbedconsole.h"
+#include "plEarlz.h"
+#include <stdarg.h>
+//Basically a non-conforming take on Forth, btw.
+
+inline int internal_captureline(void* pBuffer, char const* pFormatString, ...)
+{
+    char*   pStringEnd = (char*)pBuffer + strlen((char*)pBuffer);
+    va_list valist;
+    
+    va_start(valist, pFormatString);
+    
+    return vsprintf(pStringEnd, pFormatString, valist);
+}
+void printheapstats()
+{
+    char buffer[256];
+    __heapstats(internal_captureline, buffer);
+    vputs("Memory info: ");
+    vputs(buffer);
+}
+
+struct pl_word
+{
+
+};
+
+#define MAXSTACK 64
+#define MAXCALLS 32
+#define MAXLINELENGTH 128
+
+int pl_stackpos=0;
+int pl_stack[MAXSTACK];
+enum ErrorType
+{
+    None,
+    StackOverflow,
+    StackUnderflow
+};
+
+ErrorType pl_error=None;
+
+//int *pl_callstack[MAXCALLS];
+
+enum WordType
+{
+    Unknown,
+    Number,
+    Word,
+    Quote
+};
+
+void pl_push(int val)
+{
+    if(pl_stackpos>=MAXSTACK)
+    {
+        vputs("Stack overflow!");
+        pl_error=StackOverflow;
+        return;
+    }
+    pl_stack[pl_stackpos]=val;
+    pl_stackpos++;
+}
+int pl_pop()
+{
+    if(pl_stackpos<=0)
+    {
+        vputs("Stack underflow!");
+        pl_error=StackUnderflow;
+        return 0;
+    }
+    pl_stackpos--;
+    return pl_stack[pl_stackpos];
+}
+
+void execute_word(char *word, WordType type)
+{
+    if(type==Number){
+        pl_push(atoi(word));
+    }else{
+        if(word[1]==0 && word[0]=='.')
+        {
+            int tmp=pl_pop();
+            sprintf( word, "%i\n", tmp);
+            vputs(word);
+        }else{
+            vputs("I don't know the word ");
+            vputs(word);
+            vputs("\n");
+        }
+    }
+
+}
+
+void parse_line(char *line)
+{
+    int len=strlen(line);
+    char word[16];
+    word[0]=0;
+    int wordpos=0;
+    WordType type=Unknown;
+    for(int i=0;i<len;i++)
+    {
+        char c=line[i];
+        if(is_whitespace(c))
+        {
+            if(word[0]!=0)
+            {
+                word[wordpos]=0;
+                execute_word(word,type);
+                word[0]=0;
+            }
+            wordpos=0;
+            type=Unknown;
+        }else if(is_numeric(c)){
+            if(type==Unknown){
+                type=Number;
+            }
+            word[wordpos]=c;
+            wordpos++;
+        }else if(is_quote(c)){
+            vputs("This isn't supported yet foo!");
+            return;
+        }else{
+            if(type==Number){
+                vputs("Syntax Error! Unexpected symbol in the middle of a number");
+                return;
+            }
+            type=Word;
+            word[wordpos]=c;
+            wordpos++;
+        }
+    }
+}
+
+
+
+int pl_shell()
+{
+    vputs(">>plEarlz -- A forth-ish shell<<\n");
+    printheapstats();
+    vputs("\n");
+    char *line=(char*)malloc(MAXLINELENGTH);
+    sprintf(line, "Stack Size: %i; Max Recursion Level %i; Loaded WORDs: %i", MAXSTACK, MAXCALLS, 0);
+    vputs(line);
+    sprintf(line, "Max line length: %i\n", MAXLINELENGTH);
+    vputs(line);
+    char *tmp=(char*)malloc(32); //for constructing words/elements
+    while(1)
+    {
+        vputs("cmd> ");
+        vgetsl(line, MAXLINELENGTH);
+        line[MAXLINELENGTH-1]=0;
+        int len=strlen(line);
+        line[len]='\n';
+        line[len+1]=0;
+        parse_line(line);
+    
+    }
+    free(line);
+    free(tmp);
+    return 0;
+}
+
+