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This commit is contained in:
Joseph Poirier 2015-06-10 16:30:11 -05:00
parent 09fd02eb62
commit 7300c8e352
1 changed files with 33 additions and 20 deletions
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53
README.md
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@ -55,10 +55,9 @@ Here's an example script:
```
printf("Starting my script\n");
int total = 0;
int i;
for (i = 0; i < 10; i++)
{
int total = 0;
for (i = 0; i < 10; i++) {
printf("i = %d\n", i);
total += i;
}
@ -197,11 +196,11 @@ the functions it defines. For example:
```
struct LibraryFunction PlatformLibrary[] =
{
{ ShowComplex, "void ShowComplex(struct complex *)" },
{ Cpeek, "int peek(int, int)" },
{ Cpoke, "void poke(int, int, int)" },
{ Crandom, "int random(int)" },
{ NULL, NULL }
ShowComplex, "void ShowComplex(struct complex *)"},
Cpeek, "int peek(int, int)"},
Cpoke, "void poke(int, int, int)"},
Crandom, "int random(int)"},
NULL, NULL}
};
```
@ -212,7 +211,10 @@ prototype. The "{ NULL, NULL }" line at the end is required.
The native C function is called with these parameters:
```
void MyCFunc(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs);
void MyCFunc(struct ParseState *Parser,
struct Value *ReturnValue,
struct Value **Param,
int NumArgs);
```
* struct ParseState *Parser - this contains internal information about the progress of parsing. It's mostly used here so error messages from your function can report the line number where an error occurred.
@ -223,7 +225,10 @@ void MyCFunc(struct ParseState *Parser, struct Value *ReturnValue, struct Value
Here's an example function definition of "random" (as defined above):
```
void Crandom(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs)
void Crandom(struct ParseState *Parser,
struct Value *ReturnValue,
struct Value **Param,
int NumArgs)
{
ReturnValue->Val->Integer = random() % Param[0]->Val->Integer;
}
@ -284,21 +289,24 @@ called before the library prototypes are defined. Here's a quick way to define
a complex number structure as if it was defined in an include file:
```
IncludeRegister("win32.h", &win32SetupFunc, &win32Functions[0], "struct complex { int i; int j; };");
IncludeRegister("win32.h",
&win32SetupFunc,
&win32Functions[0],
"struct complex {int i; int j;};");
```
Or you could just parse the structure directly:
```
const char *definition = "struct complex { int i; int j; };";
PicocParse("my lib", definition, strlen(definition), TRUE, TRUE, FALSE);
const char *definition = "struct complex {int i; int j;};";
PicocParse("my lib", definition, strlen(definition), true, false, false);
```
The same method works for defining macros too:
```
const char *definition = "#define ABS(a) ((a) < (0) ? -(a) : (a))";
PicocParse("my lib", definition, strlen(definition), TRUE, TRUE, FALSE);
PicocParse("my lib", definition, strlen(definition), true, false, false);
```
Here's a more sophisticated method, using the internal functions of picoc directly:
@ -315,7 +323,7 @@ void PlatformLibraryInit()
/* define an example structure */
Tokens = LexAnalyse(IntrinsicName, StructDefinition, strlen(StructDefinition), NULL);
LexInitParser(&Parser, StructDefinition, Tokens, IntrinsicName, TRUE, FALSE);
LexInitParser(&Parser, StructDefinition, Tokens, IntrinsicName, true, false);
TypeParse(&Parser, &ParsedType, &Identifier, &IsStatic);
HeapFree(Tokens);
}
@ -330,15 +338,16 @@ Now let's say we're going to define a function to display a complex number.
Our prototype will look like:
```
{ ShowComplex, "void ShowComplex(struct complex *)" },
{ShowComplex, "void ShowComplex(struct complex *)"},
```
And finally we can define the library function:
```
struct complex { int i; int j; }; /* make this C declaration match the picoc one */
struct complex {int i; int j;}; /* make this C declaration match the picoc one */
void ShowComplex(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs)
void ShowComplex(struct ParseState *Parser,
struct Value *ReturnValue, struct Value **Param, int NumArgs)
{
struct complex *ComplexVal = Param[0]->Val->NativePointer; /* casts the pointer */
@ -374,7 +383,7 @@ function prototype should use "..." in the parameter list to indicate the potent
extra parameters just like the standard stdarg system. Here's an example from clibrary.c:
```
{ LibPrintf, "void printf(char *, ...)" },
{LibPrintf, "void printf(char *, ...)"},
```
The NumArgs parameter to the native C function lets you know how many parameters
@ -395,7 +404,11 @@ int RobotIsExploding = 0;
void PlatformLibraryInit()
{
VariableDefinePlatformVar(NULL, "RobotIsExploding", &IntType, (union AnyValue *)&RobotIsExploding, FALSE);
VariableDefinePlatformVar(NULL,
"RobotIsExploding",
&IntType,
(union AnyValue*)&RobotIsExploding,
false);
}
```