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// Logic for parsing statements
#include <gc.h>
#include <stdbool.h>
#include "../ast.h"
#include "../util.h"
#include "context.h"
#include "errors.h"
#include "expressions.h"
#include "files.h"
#include "statements.h"
#include "suffixes.h"
#include "types.h"
#include "utils.h"
ast_t *parse_declaration(parse_ctx_t *ctx, const char *pos) {
const char *start = pos;
ast_t *var = parse_var(ctx, pos);
if (!var) return NULL;
pos = var->end;
spaces(&pos);
if (!match(&pos, ":")) return NULL;
spaces(&pos);
type_ast_t *type = optional(ctx, &pos, parse_type);
spaces(&pos);
ast_t *val = NULL;
if (match(&pos, "=")) {
val = optional(ctx, &pos, parse_extended_expr);
if (!val) {
if (optional(ctx, &pos, parse_use))
parser_err(ctx, start, pos, "'use' statements are only allowed at the top level of a file");
else parser_err(ctx, pos, eol(pos), "This is not a valid expression");
}
}
return NewAST(ctx->file, start, pos, Declare, .var = var, .type = type, .value = val);
}
ast_t *parse_assignment(parse_ctx_t *ctx, const char *pos) {
const char *start = pos;
ast_list_t *targets = NULL;
for (;;) {
ast_t *lhs = optional(ctx, &pos, parse_term);
if (!lhs) break;
targets = new (ast_list_t, .ast = lhs, .next = targets);
spaces(&pos);
if (!match(&pos, ",")) break;
whitespace(ctx, &pos);
}
if (!targets) return NULL;
spaces(&pos);
if (!match(&pos, "=")) return NULL;
if (match(&pos, "=")) return NULL; // == comparison
ast_list_t *values = NULL;
for (;;) {
ast_t *rhs = optional(ctx, &pos, parse_extended_expr);
if (!rhs) break;
values = new (ast_list_t, .ast = rhs, .next = values);
spaces(&pos);
if (!match(&pos, ",")) break;
whitespace(ctx, &pos);
}
REVERSE_LIST(targets);
REVERSE_LIST(values);
return NewAST(ctx->file, start, pos, Assign, .targets = targets, .values = values);
}
ast_t *parse_update(parse_ctx_t *ctx, const char *pos) {
const char *start = pos;
ast_t *lhs = optional(ctx, &pos, parse_expr);
if (!lhs) return NULL;
spaces(&pos);
ast_e op;
if (match(&pos, "+=")) op = PlusUpdate;
else if (match(&pos, "++=")) op = ConcatUpdate;
else if (match(&pos, "-=")) op = MinusUpdate;
else if (match(&pos, "*=")) op = MultiplyUpdate;
else if (match(&pos, "/=")) op = DivideUpdate;
else if (match(&pos, "^=")) op = PowerUpdate;
else if (match(&pos, "<<=")) op = LeftShiftUpdate;
else if (match(&pos, "<<<=")) op = UnsignedLeftShiftUpdate;
else if (match(&pos, ">>=")) op = RightShiftUpdate;
else if (match(&pos, ">>>=")) op = UnsignedRightShiftUpdate;
else if (match(&pos, "and=")) op = AndUpdate;
else if (match(&pos, "or=")) op = OrUpdate;
else if (match(&pos, "xor=")) op = XorUpdate;
else return NULL;
ast_t *rhs = expect(ctx, start, &pos, parse_extended_expr, "I expected an expression here");
return new (ast_t, .file = ctx->file, .start = start, .end = pos, .tag = op, .__data.PlusUpdate.lhs = lhs,
.__data.PlusUpdate.rhs = rhs);
}
ast_t *parse_debug_log(parse_ctx_t *ctx, const char *pos) {
const char *start = pos;
if (!match(&pos, ">>")) return NULL;
spaces(&pos);
ast_t *first_value =
expect(ctx, start, &pos, parse_statement, "I couldn't parse the expression for this debugging message");
ast_list_t *values = new (ast_list_t, .ast = first_value, .next = NULL);
spaces(&pos);
while (match(&pos, ",")) {
spaces(&pos);
ast_t *value = optional(ctx, &pos, parse_statement);
if (!value) break;
values = new (ast_list_t, .ast = value, .next = values);
spaces(&pos);
}
REVERSE_LIST(values);
// whitespace(ctx, &pos);
return NewAST(ctx->file, start, pos, DebugLog, .values = values);
}
ast_t *parse_assert(parse_ctx_t *ctx, const char *pos) {
const char *start = pos;
if (!match_word(&pos, "assert")) return NULL;
spaces(&pos);
ast_t *expr = expect(ctx, start, &pos, parse_extended_expr, "I couldn't parse the expression for this assert");
spaces(&pos);
ast_t *message = NULL;
if (match(&pos, ",")) {
whitespace(ctx, &pos);
message = expect(ctx, start, &pos, parse_extended_expr, "I couldn't parse the error message for this assert");
} else {
pos = expr->end;
}
return NewAST(ctx->file, start, pos, Assert, .expr = expr, .message = message);
}
ast_t *parse_statement(parse_ctx_t *ctx, const char *pos) {
ast_t *stmt = NULL;
if ((stmt = parse_declaration(ctx, pos)) || (stmt = parse_debug_log(ctx, pos)) || (stmt = parse_assert(ctx, pos)))
return stmt;
if (!(false || (stmt = parse_update(ctx, pos)) || (stmt = parse_assignment(ctx, pos))))
stmt = parse_extended_expr(ctx, pos);
for (bool progress = (stmt != NULL); progress;) {
ast_t *new_stmt;
progress = false;
if (stmt->tag == Var) {
progress = (false || (new_stmt = parse_method_call_suffix(ctx, stmt))
|| (new_stmt = parse_fncall_suffix(ctx, stmt)));
} else if (stmt->tag == FunctionCall) {
new_stmt = parse_optional_conditional_suffix(ctx, stmt);
progress = (new_stmt != stmt);
}
if (progress) stmt = new_stmt;
}
return stmt;
}
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