/
tree.R
172 lines (147 loc) · 3.4 KB
/
tree.R
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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
#' Display the abstract syntax tree
#'
#' This is a useful alterantive to \code{str()} for expression objects.
#'
#' @param x A language object to display.
#' @export
#' @examples
#' # Leaves
#' ast(1)
#' ast(x)
#'
#' # Simple calls
#' ast(f())
#' ast(f(x, 1, g(), h(i())))
#' ast(f()())
#' ast(f(x)(y))
#'
#' ast((x + 1))
#'
#' # All operations have this same structure
#' ast(if (TRUE) 3 else 4)
#' ast(y <- x * 10)
#' ast(function(x = 1, y = 2) { x + y } )
#'
#' # Operator precedence
#' ast(1 * 2 + 3)
#' ast(!1 + !1)
ast <- function(x) {
expr <- enexpr(x)
out <- tree(expr)
structure(out, class = "lobstr_ast")
}
#' @export
print.lobstr_ast <- function(x, ...) {
cat(paste(x, "\n", collapse = ""), sep = "")
invisible(x)
}
tree <- function(x, layout = box_chars()) {
if (is_quosure(x)) {
x <- quo_expr(x)
}
# base cases
if (rlang::is_syntactic_literal(x)) {
return(leaf_constant(x))
} else if (is_symbol(x)) {
return(leaf_symbol(x))
} else if (!is.pairlist(x) && !is.call(x)) {
return(paste0("<inline ", paste0(class(x), collapse = "/"), ">"))
}
# recursive case
subtrees <- lapply(x, tree, layout = layout)
subtrees <- name_subtree(subtrees)
n <- length(x)
if (n == 0) {
character()
} else if (n == 1) {
str_indent(subtrees[[1]],
paste0(layout$n, layout$h),
" "
)
} else {
c(
str_indent(subtrees[[1]],
paste0(layout$n, layout$h),
paste0(layout$v, " ")
),
unlist(lapply(subtrees[-c(1, n)],
str_indent,
paste0(layout$j, layout$h),
paste0(layout$v, " ")
)),
str_indent(subtrees[[n]],
paste0(layout$l, layout$h),
" "
)
)
}
}
name_subtree <- function(x) {
nm <- names(x)
if (is.null(nm))
return(x)
grey <- crayon::make_style(grDevices::grey(0.5), grey = TRUE)
has_name <- nm != ""
label <- paste0(crayon::italic(grey(nm)), " = ")
indent <- strrep(" ", nchar(nm) + 3)
x[has_name] <- Map(str_indent, x[has_name], label[has_name], indent[has_name])
x
}
box_chars <- function() {
fancy <- getOption("pkgdepends.fancy.tree") %||% l10n_info()$`UTF-8`
orange <- crayon::make_style("orange")
if (fancy) {
list(
"h" = "\u2500", # ─ horizontal
"v" = "\u2502", # │ vertical
"l" = "\u2514", # └ leaf
"j" = "\u251C", # ├ junction
"n" = orange("\u2588") # █ node
)
} else {
list(
"h" = "-",
"v" = "|",
"l" = "\\",
"j" = "+",
"n" = orange("X")
)
}
}
leaf_symbol <- function(x) {
x <- as.character(x)
if (!is.syntactic(x)) {
x <- encodeString(x, quote = "`")
}
crayon::bold(crayon::magenta(x))
}
leaf_constant <- function(x) {
if (is.character(x)) {
encodeString(x, quote = '"')
} else {
as.character(x)
}
}
is.syntactic <- function(x) make.names(x) == x
# string utils ------------------------------------------------------------
str_indent <- function(x, first, rest) {
if (length(x) == 0) {
character()
} else if (length(x) == 1) {
paste0(first, x)
} else {
c(
paste0(first, x[[1]]),
paste0(rest, x[-1L])
)
}
}
str_trunc <- function(x, max_width = getOption("width")) {
width <- nchar(x)
too_wide <- width > max_width
x[too_wide] <- paste0(substr(x[too_wide], 1, width[too_wide] - 3), "...")
x
}
str_dup <- function(x, n) {
paste0(rep(x, n), collapse = "")
}