getchar()/gets() implemented

git-svn-id: http://picoc.googlecode.com/svn/trunk@205 21eae674-98b7-11dd-bd71-f92a316d2d60

TODO

@@ -27,6 +27,7 @@ Improvements:
 
 Need test/debug:
 * all break/continue variations
+* getchar()/gets() tests
 
 Also:
 * Remove Var parameter from HeapPopStack() once we're certain it all works

clibrary.c

@@ -161,12 +161,30 @@ void LibPrintf(struct ParseState *Parser, struct Value *ReturnValue, struct Valu
     }
 }
 
+/* get a line of input. protected from buffer overrun */
 void LibGets(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs)
 {
+    struct Value *CharArray = Param[0]->Val->Pointer.Segment;
+    char *ReadBuffer = CharArray->Val->Array.Data + Param[0]->Val->Pointer.Offset;
+    int MaxLength = CharArray->Val->Array.Size - Param[0]->Val->Pointer.Offset;
+    char *Result;
+
+    ReturnValue->Val->Pointer.Segment = 0;
+    ReturnValue->Val->Pointer.Offset = 0;
+    
+    if (Param[0]->Val->Pointer.Offset < 0 || MaxLength < 0)
+        return; /* no room for data */
+    
+    Result = PlatformGetLine(ReadBuffer, MaxLength);
+    if (Result == NULL)
+        return;
+    
+    ReturnValue->Val->Pointer = Param[0]->Val->Pointer;
 }
 
 void LibGetc(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs)
 {
+    ReturnValue->Val->Integer = PlatformGetCharacter();
 }
 
 /* list of all library functions and their prototypes */
@@ -174,6 +192,6 @@ struct LibraryFunction CLibrary[] =
 {
     { LibPrintf,        "void printf(char *, ...)" },
     { LibGets,          "void gets(char *, int)" },
-    { LibGetc,          "int getc()" },
+    { LibGetc,          "int getchar()" },
     { NULL,             NULL }
 };

picoc.h

@@ -326,6 +326,7 @@ void LexFail(struct LexState *Lexer, const char *Message, ...);
 void PlatformCleanup();
 void PlatformScanFile(const char *FileName);
 char *PlatformGetLine(char *Buf, int MaxLen);
+int PlatformGetCharacter();
 void PlatformPutc(unsigned char OutCh);
 void PlatformPrintf(const char *Format, ...);
 void PlatformVPrintf(const char *Format, va_list Args);

platform_surveyor.c

@@ -37,8 +37,8 @@ void PlatformPutc(unsigned char OutCh)
     putchar(OutCh);
 }
 
-/* write a character to the console */
-int PlatformGetc()
+/* read a character */
+int PlatformGetCharacter()
 {
     return getch();
 }

platform_unix.c

@@ -17,6 +17,13 @@ char *PlatformGetLine(char *Buf, int MaxLen)
     return fgets(Buf, MaxLen, stdin);
 }
 
+/* get a character of interactive input */
+int PlatformGetCharacter()
+{
+    fflush(stdout);
+    return getchar();
+}
+
 /* write a character to the console */
 void PlatformPutc(unsigned char OutCh)
 {