check-list.txt

- variable declaration

[qualifiers] type name [=...], ...;
type name1, name2;
type name = expr;
type name1 = expr, name2;

at most one storage qualifier

- fonction declaration

type name(params);

----------------------------------------------------------------------
-- illegal
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int float; // float is reserved
int gl_foo; // gl_ prefix is reserved unless for redeclaration
int foo__bar; // double underscore is reserved

int 1a;

f(); // return type should be void if f doesn't return a value
void i; // void only for return type or parameter
bool done = 1; // 1 is no of type bool
int i = 5000000000; // value too large

sampler2D a; // samplers can be used only to declare uniforms or as function parameters
// samplers can not be operands in expressions (except for array indexing, structure field selection and in parentheses
a = ...; // sampler can't be assigned to, nor used as out, nor initialized.
// more in 4.1.7

qual struct name { ... }; // qualifier qual can be present only with declarators
struct { qual int a; }; // qual can only be a precision qualifier
struct { int a = 1; }; // no initializers
struct { int a[]; }; // array size should be specified by a integral constant expression greater than zero
// anonymous structures and nested structures are not allowed

// array size in declaration should be integral constant expression
// array size con be omitted then redeclared
// array size in parameter should be integral constant expression
float a[5][3]; // array of arrays is illegal
float[5] a[3]; // same thing
//implicitlty sized arrays cannot be assigned or cannot be applied the length method.

//fonction declaration should occur at global scope