1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130

use ast;
use ast::Ast;
use std::convert::TryInto;
use std::ffi::CStr;
use std::fmt;
use z3_sys::*;
use {Context, FuncDecl, Sort, Symbol};

impl<'ctx> FuncDecl<'ctx> {
    pub(crate) unsafe fn wrap(ctx: &'ctx Context, z3_func_decl: Z3_func_decl) -> Self {
        Z3_inc_ref(ctx.z3_ctx, Z3_func_decl_to_ast(ctx.z3_ctx, z3_func_decl));
        Self { ctx, z3_func_decl }
    }

    pub fn new<S: Into<Symbol>>(
        ctx: &'ctx Context,
        name: S,
        domain: &[&Sort<'ctx>],
        range: &Sort<'ctx>,
    ) -> Self {
        assert!(domain.iter().all(|s| s.ctx.z3_ctx == ctx.z3_ctx));
        assert_eq!(ctx.z3_ctx, range.ctx.z3_ctx);

        let domain: Vec<_> = domain.iter().map(|s| s.z3_sort).collect();

        unsafe {
            Self::wrap(
                ctx,
                Z3_mk_func_decl(
                    ctx.z3_ctx,
                    name.into().as_z3_symbol(ctx),
                    domain.len().try_into().unwrap(),
                    domain.as_ptr(),
                    range.z3_sort,
                ),
            )
        }
    }

    /// Return the number of arguments of a function declaration.
    ///
    /// If the function declaration is a constant, then the arity is `0`.
    ///
    /// ```
    /// # use z3::{Config, Context, FuncDecl, Solver, Sort, Symbol};
    /// # let cfg = Config::new();
    /// # let ctx = Context::new(&cfg);
    /// let f = FuncDecl::new(
    ///     &ctx,
    ///     "f",
    ///     &[&Sort::int(&ctx), &Sort::real(&ctx)],
    ///     &Sort::int(&ctx));
    /// assert_eq!(f.arity(), 2);
    /// ```
    pub fn arity(&self) -> usize {
        unsafe { Z3_get_arity(self.ctx.z3_ctx, self.z3_func_decl) as usize }
    }

    /// Create a constant (if `args` has length 0) or function application (otherwise).
    ///
    /// Note that `args` should have the types corresponding to the `domain` of the `FuncDecl`.
    pub fn apply(&self, args: &[&dyn ast::Ast<'ctx>]) -> ast::Dynamic<'ctx> {
        assert!(args.iter().all(|s| s.get_ctx().z3_ctx == self.ctx.z3_ctx));

        let args: Vec<_> = args.iter().map(|a| a.get_z3_ast()).collect();

        unsafe {
            ast::Dynamic::wrap(self.ctx, {
                Z3_mk_app(
                    self.ctx.z3_ctx,
                    self.z3_func_decl,
                    args.len().try_into().unwrap(),
                    args.as_ptr(),
                )
            })
        }
    }

    /// Return the `DeclKind` of this `FuncDecl`.
    pub fn kind(&self) -> DeclKind {
        unsafe { Z3_get_decl_kind(self.ctx.z3_ctx, self.z3_func_decl) }
    }

    /// Return the name of this `FuncDecl`.
    ///
    /// Strings will return the `Symbol`.  Ints will have a `"k!"` prepended to
    /// the `Symbol`.
    pub fn name(&self) -> String {
        unsafe {
            let z3_ctx = self.ctx.z3_ctx;
            let symbol = Z3_get_decl_name(z3_ctx, self.z3_func_decl);
            match Z3_get_symbol_kind(z3_ctx, symbol) {
                SymbolKind::String => CStr::from_ptr(Z3_get_symbol_string(z3_ctx, symbol))
                    .to_string_lossy()
                    .into_owned(),
                SymbolKind::Int => format!("k!{}", Z3_get_symbol_int(z3_ctx, symbol)),
            }
        }
    }
}

impl<'ctx> fmt::Display for FuncDecl<'ctx> {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        let p = unsafe { Z3_func_decl_to_string(self.ctx.z3_ctx, self.z3_func_decl) };
        if p.is_null() {
            return Result::Err(fmt::Error);
        }
        match unsafe { CStr::from_ptr(p) }.to_str() {
            Ok(s) => write!(f, "{}", s),
            Err(_) => Result::Err(fmt::Error),
        }
    }
}

impl<'ctx> fmt::Debug for FuncDecl<'ctx> {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        <Self as fmt::Display>::fmt(self, f)
    }
}

impl<'ctx> Drop for FuncDecl<'ctx> {
    fn drop(&mut self) {
        unsafe {
            Z3_dec_ref(
                self.ctx.z3_ctx,
                Z3_func_decl_to_ast(self.ctx.z3_ctx, self.z3_func_decl),
            );
        }
    }
}