mirror of
https://github.com/krgamestudios/Toy.git
synced 2026-04-15 23:04:08 +10:00
69 lines
2.2 KiB
Markdown
69 lines
2.2 KiB
Markdown
# toy_parser.h
|
|
|
|
This header defines the structure `Toy_Parser` which, after being initialized with a `Toy_Lexer` produces a series of abstract syntax trees to be passed to the `Toy_Compiler`. The following is a utility function provided by [repl_tools.h](repl_tools_h.md), demonstrating how to use the parser.
|
|
|
|
```c
|
|
//generate bytecode from a given string
|
|
const unsigned char* Toy_compileString(const char* source, size_t* size) {
|
|
//declare the relevant instances
|
|
Toy_Lexer lexer;
|
|
Toy_Parser parser;
|
|
Toy_Compiler compiler;
|
|
|
|
//initialize each of them
|
|
Toy_initLexer(&lexer, source);
|
|
Toy_initParser(&parser, &lexer);
|
|
Toy_initCompiler(&compiler);
|
|
|
|
//when the parser returns NULL, it is finished
|
|
Toy_ASTNode* node = Toy_scanParser(&parser);
|
|
while(node != NULL) {
|
|
//if the parser returns an error node, clean up and exit gracefully
|
|
if (node->type == TOY_AST_NODE_ERROR) {
|
|
Toy_freeASTNode(node);
|
|
Toy_freeCompiler(&compiler);
|
|
Toy_freeParser(&parser);
|
|
//no need to clean the lexer
|
|
return NULL;
|
|
}
|
|
|
|
//write the node to the compiler
|
|
Toy_writeCompiler(&compiler, node);
|
|
Toy_freeASTNode(node);
|
|
|
|
//grab the next node
|
|
node = Toy_scanParser(&parser);
|
|
}
|
|
|
|
//get the bytecode to be returned
|
|
const unsigned char* tb = Toy_collateCompiler(&compiler, size);
|
|
|
|
//cleanup
|
|
Toy_freeCompiler(&compiler);
|
|
Toy_freeParser(&parser);
|
|
//no need to clean the lexer
|
|
|
|
//finally
|
|
return tb;
|
|
}
|
|
```
|
|
|
|
This header also includes [toy_ast_node.h](toy_ast_node_h.md), so the `Toy_freeASTNode` function can also be used.
|
|
|
|
## Defined Functions
|
|
|
|
### void Toy_initParser(Toy_Parser* parser, Toy_Lexer* lexer)
|
|
|
|
This function initializes a `Toy_Parser`, binding the given `Toy_Lexer` to it.
|
|
|
|
### void Toy_freeParser(Toy_Parser* parser)
|
|
|
|
This function frees a `Toy_Parser` once its task is completed.
|
|
|
|
### Toy_ASTNode* Toy_scanParser(Toy_Parser* parser)
|
|
|
|
This function returns an abstract syntax tree representing part of the program, or an error node. The abstract syntax tree must be passed to `Toy_writeCompiler` and/or `Toy_freeASTNode`.
|
|
|
|
This function should be called repeatedly until it returns `NULL`, indicating the end of the program.
|
|
|