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-rw-r--r--compile.c138
-rw-r--r--stdlib/util.h2
-rw-r--r--typecheck.c13
3 files changed, 71 insertions, 82 deletions
diff --git a/compile.c b/compile.c
index ca09b59c..404694ef 100644
--- a/compile.c
+++ b/compile.c
@@ -419,6 +419,26 @@ static CORD check_null(type_t *t, CORD value)
errx(1, "Optional check not implemented for: %T", t);
}
+static CORD compile_condition(env_t *env, ast_t *ast)
+{
+ type_t *t = get_type(env, ast);
+ if (t->tag == BoolType) {
+ return compile(env, ast);
+ } else if (t->tag == TextType) {
+ return CORD_all("(", compile(env, ast), ").length");
+ } else if (t->tag == ArrayType) {
+ return CORD_all("(", compile(env, ast), ").length");
+ } else if (t->tag == TableType || t->tag == SetType) {
+ return CORD_all("(", compile(env, ast), ").entries.length");
+ } else if (t->tag == OptionalType) {
+ return CORD_all("!", check_null(t, compile(env, ast)));
+ } else if (t->tag == PointerType) {
+ code_err(ast, "This pointer will always be non-null, so it should not be used in a conditional.");
+ } else {
+ code_err(ast, "%T values cannot be used for conditionals", t);
+ }
+}
+
CORD compile_statement(env_t *env, ast_t *ast)
{
switch (ast->tag) {
@@ -1384,50 +1404,37 @@ CORD compile_statement(env_t *env, ast_t *ast)
case If: {
auto if_ = Match(ast, If);
ast_t *condition = if_->condition;
- CORD code = CORD_EMPTY;
if (condition->tag == Declare) {
- env = fresh_scope(env);
- code = compile_statement(env, condition);
- bind_statement(env, condition);
- condition = Match(condition, Declare)->var;
- }
-
- type_t *cond_t = get_type(env, condition);
- if (cond_t->tag == PointerType)
- code_err(condition, "This pointer will always be non-null, so it should not be used in a conditional.");
-
- env_t *truthy_scope = env;
- CORD condition_code;
- if (cond_t->tag == TextType) {
- condition_code = CORD_all("(", compile(env, condition), ").length");
- } else if (cond_t->tag == ArrayType) {
- condition_code = CORD_all("(", compile(env, condition), ").length");
- } else if (cond_t->tag == TableType || cond_t->tag == SetType) {
- condition_code = CORD_all("(", compile(env, condition), ").entries.length");
- } else if (cond_t->tag == OptionalType) {
- if (condition->tag == Var) {
- truthy_scope = fresh_scope(env);
- const char *varname = Match(condition, Var)->name;
- binding_t *b = get_binding(env, varname);
- assert(b);
- set_binding(truthy_scope, varname,
+ env_t *truthy_scope = fresh_scope(env);
+ CORD code = CORD_all("IF_DECLARE(", compile_statement(truthy_scope, condition), ", ");
+ bind_statement(truthy_scope, condition);
+ ast_t *var = Match(condition, Declare)->var;
+ code = CORD_all(code, compile_condition(truthy_scope, var), ", ");
+ type_t *cond_t = get_type(truthy_scope, var);
+ if (cond_t->tag == OptionalType) {
+ set_binding(truthy_scope, Match(var, Var)->name,
new(binding_t, .type=Match(cond_t, OptionalType)->type,
- .code=optional_into_nonnull(cond_t, b->code)));
+ .code=optional_into_nonnull(cond_t, compile(truthy_scope, var))));
}
- condition_code = CORD_all("!", check_null(cond_t, compile(env, condition)));
- } else if (cond_t->tag == BoolType) {
- condition_code = compile(env, condition);
+ code = CORD_all(code, compile_statement(truthy_scope, if_->body), ")");
+ if (if_->else_body)
+ code = CORD_all(code, "\nelse ", compile_statement(env, if_->else_body));
+ return code;
} else {
- code_err(condition, "%T values cannot be used for conditionals", cond_t);
+ CORD code = CORD_all("if (", compile_condition(env, condition), ")");
+ env_t *truthy_scope = env;
+ type_t *cond_t = get_type(env, condition);
+ if (condition->tag == Var && cond_t->tag == OptionalType) {
+ truthy_scope = fresh_scope(env);
+ set_binding(truthy_scope, Match(condition, Var)->name,
+ new(binding_t, .type=Match(cond_t, OptionalType)->type,
+ .code=optional_into_nonnull(cond_t, compile(truthy_scope, condition))));
+ }
+ code = CORD_all(code, compile_statement(truthy_scope, if_->body));
+ if (if_->else_body)
+ code = CORD_all(code, "\nelse ", compile_statement(env, if_->else_body));
+ return code;
}
-
- code = CORD_all(code, "if (", condition_code, ")", compile_statement(truthy_scope, if_->body));
- if (if_->else_body)
- code = CORD_all(code, "\nelse ", compile_statement(env, if_->else_body));
-
- if (if_->condition->tag == Declare)
- code = CORD_all("{\n", code, "}\n");
- return code;
}
case Block: {
return CORD_all("{\n", compile_inline_block(env, ast), "}\n");
@@ -3180,52 +3187,31 @@ CORD compile(env_t *env, ast_t *ast)
CORD decl_code = CORD_EMPTY;
env_t *truthy_scope = env, *falsey_scope = env;
- type_t *condition_type;
+ CORD condition_code;
if (condition->tag == Declare) {
- condition_type = get_type(env, Match(condition, Declare)->value);
-
- const char *varname = Match(Match(condition, Declare)->var, Var)->name;
- falsey_scope = fresh_scope(env);
- bind_statement(falsey_scope, condition);
- binding_t *b = get_binding(falsey_scope, varname);
- assert(b);
-
- truthy_scope = fresh_scope(env);
- set_binding(truthy_scope, varname,
- new(binding_t, .type=Match(condition_type, OptionalType)->type, .code=b->code));
+ type_t *condition_type = get_type(env, Match(condition, Declare)->value);
+ if (condition_type->tag != OptionalType)
+ code_err(condition, "This `if var := ...:` declaration should be an optional type, not %T", condition_type);
decl_code = compile_statement(env, condition);
- condition = Match(condition, Declare)->var;
+ ast_t *var = Match(condition, Declare)->var;
+ truthy_scope = fresh_scope(env);
+ bind_statement(truthy_scope, condition);
+ condition_code = compile_condition(truthy_scope, var);
+ set_binding(truthy_scope, Match(var, Var)->name,
+ new(binding_t, .type=Match(condition_type, OptionalType)->type,
+ .code=optional_into_nonnull(condition_type, compile(truthy_scope, var))));
} else if (condition->tag == Var) {
- condition_type = get_type(env, condition);
+ type_t *condition_type = get_type(env, condition);
+ condition_code = compile(env, condition);
if (condition_type->tag == OptionalType) {
truthy_scope = fresh_scope(env);
- const char *varname = Match(if_->condition, Var)->name;
- binding_t *b = get_binding(env, varname);
- if (!b) code_err(condition, "I don't know what this variable refers to");
- set_binding(truthy_scope, varname,
- new(binding_t, .type=Match(condition_type, OptionalType)->type, .code=b->code));
+ set_binding(truthy_scope, Match(condition, Var)->name,
+ new(binding_t, .type=Match(condition_type, OptionalType)->type,
+ .code=optional_into_nonnull(condition_type, compile(truthy_scope, condition))));
}
} else {
- condition_type = get_type(env, condition);
- }
-
- if (condition_type->tag == PointerType)
- code_err(condition, "This pointer will always be non-null, so it should not be used in a conditional.");
-
- CORD condition_code;
- if (condition_type->tag == TextType) {
- condition_code = CORD_all("(", compile(env, condition), ").length");
- } else if (condition_type->tag == ArrayType) {
- condition_code = CORD_all("(", compile(env, condition), ").length");
- } else if (condition_type->tag == TableType || condition_type->tag == SetType) {
- condition_code = CORD_all("(", compile(env, condition), ").entries.length");
- } else if (condition_type->tag == OptionalType) {
- condition_code = CORD_all("!", check_null(condition_type, compile(env, condition)));
- } else if (condition_type->tag == BoolType) {
condition_code = compile(env, condition);
- } else {
- code_err(condition, "%T values cannot be used for conditionals", condition_type);
}
type_t *true_type = get_type(truthy_scope, if_->body);
diff --git a/stdlib/util.h b/stdlib/util.h
index fb708476..310ba905 100644
--- a/stdlib/util.h
+++ b/stdlib/util.h
@@ -17,6 +17,8 @@
#define check_initialized(var, name) *({ if (!var ## $initialized) fail("The variable " name " is being accessed before it has been initialized!"); \
&var; })
+#define IF_DECLARE(decl, expr, block) if (({ decl; expr ? ({ block; 1; }) : 0; })) {}
+
#ifndef auto
#define auto __auto_type
#endif
diff --git a/typecheck.c b/typecheck.c
index f844d30d..915e2b5c 100644
--- a/typecheck.c
+++ b/typecheck.c
@@ -1088,15 +1088,16 @@ type_t *get_type(env_t *env, ast_t *ast)
env_t *falsey_scope = env;
if (if_->condition->tag == Declare) {
type_t *condition_type = get_type(env, Match(if_->condition, Declare)->value);
- falsey_scope = fresh_scope(env);
- bind_statement(falsey_scope, if_->condition);
-
const char *varname = Match(Match(if_->condition, Declare)->var, Var)->name;
- if (!streq(varname, "_")) {
- truthy_scope = fresh_scope(env);
+ if (streq(varname, "_"))
+ code_err(if_->condition, "To use `if var := ...:`, you must choose a real variable name, not `_`");
+
+ truthy_scope = fresh_scope(env);
+ if (condition_type->tag == OptionalType)
set_binding(truthy_scope, varname,
new(binding_t, .type=Match(condition_type, OptionalType)->type));
- }
+ else
+ set_binding(truthy_scope, varname, new(binding_t, .type=condition_type));
} else if (if_->condition->tag == Var) {
type_t *condition_type = get_type(env, if_->condition);
if (condition_type->tag == OptionalType) {
generated by cgit v1.2.3 (git 2.25.1) at 2026-03-01 11:49:00 +0000