5 { $values { "seq" "a sequence" } { "first" "the first element" } { "second" "the second element" } }
6 { $description "Pushes the first two elements of a sequence." }
7 { $errors "Throws an error if the sequence has less than two elements." } ;
10 { $values { "seq" "a sequence" } { "first" "the first element" } { "second" "the second element" } { "third" "the third element" } }
11 { $description "Pushes the first three elements of a sequence." }
12 { $errors "Throws an error if the sequence has less than three elements." } ;
15 { $values { "seq" "a sequence" } { "first" "the first element" } { "second" "the second element" } { "third" "the third element" } { "fourth" "the fourth element" } }
16 { $description "Pushes the first four elements of a sequence." }
17 { $errors "Throws an error if the sequence has less than four elements." } ;
20 { $values { "obj" "an object" } { "seq" "a sequence" } }
21 { $description "Outputs the index of the first element in the sequence equal to " { $snippet "obj" } ". If no element is found, outputs -1." }
22 { $see-also index* member? } ;
25 { $values { "obj" "an object" } { "i" "a start index" } { "seq" "a sequence" } }
26 { $description "Outputs the index of the first element in the sequence equal to " { $snippet "obj" } ", starting the search from the " { $snippet "i" } "th element. If no element is found, outputs -1." }
27 { $see-also index member? } ;
30 { $values { "obj" "an object" } { "seq" "a sequence" } }
31 { $description "Outputs the index of the last element in the sequence equal to " { $snippet "obj" } "; the sequence is traversed back to front. If no element is found, outputs -1." }
32 { $see-also index* member? } ;
35 { $values { "obj" "an object" } { "i" "a start index" } { "seq" "a sequence" } }
36 { $description "Outputs the index of the last element in the sequence equal to " { $snippet "obj" } ", traversing the sequence backwards starting from the " { $snippet "i" } "th element and finishing at the first. If no element is found, outputs -1." }
37 { $see-also index member? } ;
40 { $values { "obj" "an object" } { "seq" "a sequence" } }
41 { $description "Tests if the sequence contains an element equal to the object." }
42 { $see-also index index* memq? } ;
45 { $values { "obj" "an object" } { "seq" "a sequence" } }
46 { $description "Tests if the sequence contains the object." }
48 "This word uses identity comparison, so the following will most likely print " { $link f } ":"
49 { $example "\"hello\" { \"hello\" } memq? ." "f" }
51 { $see-also index index* member? } ;
54 { $values { "elt" "an object" } { "seq" "a sequence" } { "newseq" "a new sequence" } }
55 { $description "Outputs a new sequence containing all elements of the input sequence except those equal to the given element." } ;
58 { $values { "newseq" "a sequence" } { "oldseq" "a mutable sequence" } { "seq" "a sequence" } }
59 { $description "Searches for every element of " { $snippet "seq" } " in " { $snippet "oldseq" } "; if a match is found, the element is replaced by the element of " { $snippet "oldseq" } " at the same index." }
60 { $side-effects "seq" } ;
63 { $values { "m" "an index in " { $snippet "seq" } } { "n" "an index in " { $snippet "seq" } } { "seq" "a mutable sequence" } }
64 { $description "Sets the element with index " { $snippet "m" } " to the element with index " { $snippet "n" } "." }
65 { $side-effects "seq" } ;
68 { $values { "elt" "an object" } { "seq" "a resizable mutable sequence" } }
69 { $description "Removes all elements equal to " { $snippet "elt" } " from " { $snippet "seq" } "." }
70 { $side-effects "seq" } ;
73 { $values { "elt" "an object" } { "seq" "a resizable mutable sequence" } }
74 { $description "Removes all elements equal to " { $snippet "elt" } ", and adds " { $snippet "elt" } " at the end of the sequence." }
77 "V{ \"beans\" \"salsa\" \"cheese\" } \"v\" set"
78 "\"nachos\" \"v\" get push-new"
79 "\"salsa\" \"v\" get push-new"
81 "V{ \"beans\" \"cheese\" \"nachos\" \"salsa\" }"
84 { $side-effects "seq" }
88 { $values { "seq" "a sequence" } { "newseq" "a sequence" } }
89 { $description "Outputs a new sequence with each distinct element of " { $snippet "seq" } " appearing only once. Elements are compared for equality using " { $link = } " and elements are ordered according to their position in " { $snippet "seq" } "." } ;
92 { $values { "dest" "a resizable mutable sequence" } { "src" "a sequence" } }
93 { $description "Appends " { $snippet "src" } " to the end of " { $snippet "dest" } "." }
94 { $side-effects "dest" }
95 { $errors "Throws an error if " { $snippet "src" } " contains elements not permitted in " { $snippet "dest" } "." } ;
98 { $values { "seq" "a sequence" } { "elt" "an object" } { "newseq" "a sequence" } }
99 { $description "Outputs a new sequence obtained by adding " { $snippet "elt" } " at the end of " { $snippet "seq" } "." }
100 { $errors "Throws an error if the type of " { $snippet "elt" } " is not permitted in sequences of the same class as " { $snippet "seq1" } "." }
102 { $example "{ 1 2 3 } 4 add ." "{ 1 2 3 4 }" }
106 { $values { "seq" "a sequence" } { "elt" "an object" } { "newseq" "a sequence" } }
107 { $description "Outputs a new sequence obtained by adding " { $snippet "elt" } " at the beginning of " { $snippet "seq" } "." }
108 { $errors "Throws an error if the type of " { $snippet "elt" } " is not permitted in sequences of the same class as " { $snippet "seq1" } "." }
110 { $example "{ 1 2 3 } 0 add* ." "{ 0 1 2 3 }" }
114 { $values { "seq1" "a sequence" } { "seq2" "a sequence" } { "newseq" "a sequence" } }
115 { $description "Outputs a sequence consisting of elements present in " { $snippet "seq2" } " but not " { $snippet "seq1" } ", comparing elements for equality." } ;
118 { $values { "seq1" "a sequence" } { "seq2" "a sequence" } { "newseq" "a sequence" } }
119 { $description "Outputs a new sequence of the same type as " { $snippet "seq1" } " consisting of the elements of " { $snippet "seq1" } " followed by " { $snippet "seq2" } "." }
120 { $errors "Throws an error if " { $snippet "seq2" } " contains elements not permitted in sequences of the same class as " { $snippet "seq1" } "." } ;
123 { $values { "seq1" "a sequence" } { "seq2" "a sequence" } { "seq3" "a sequence" } { "newseq" "a sequence" } }
124 { $description "Outputs a new sequence consisting of the elements of " { $snippet "seq1" } ", " { $snippet "seq2" } " and " { $snippet "seq3" } " in turn." }
125 { $errors "Throws an error if " { $snippet "seq2" } " or " { $snippet "seq3" } " contain elements not permitted in sequences of the same class as " { $snippet "seq1" } "." } ;
128 { $values { "seq" "a sequence" } { "newseq" "a sequence" } }
129 { $description "Concatenates a sequence of sequences together into one sequence. The resulting sequence is of the same class as the first element of " { $snippet "seq" } "." }
130 { $errors "Throws an error if one of the sequences in " { $snippet "seq" } " contains elements not permitted in sequences of the same class as the first element of " { $snippet "seq" } "." }
134 { $values { "seq" "a sequence" } { "elt" "an object" } }
135 { $description "Outputs the last element of a sequence." }
136 { $errors "Throws an error if the sequence is empty." }
137 { $see-also pop* pop } ;
140 { $values { "seq" "a resizable mutable sequence" } }
141 { $description "Removes the last element and shortens the sequence." }
142 { $side-effects "seq" }
143 { $errors "Throws an error if the sequence is empty." }
144 { $see-also peek pop } ;
147 { $values { "seq" "a resizable mutable sequence" } { "elt" "an object" } }
148 { $description "Outputs the last element after removing it and shortening the sequence." }
149 { $side-effects "seq" }
150 { $errors "Throws an error if the sequence is empty." }
151 { $see-also peek pop* } ;
154 { $values { "seq" "a sequence" } { "?" "a boolean" } }
155 { $description "Tests if all elements in the sequence are equal. Yields true with an empty sequence." } ;
158 { $values { "seq" "a sequence" } { "?" "a boolean" } }
159 { $description "Tests if all elements in the sequence are the same identical object. Yields true with an empty sequence." } ;
162 { $values { "seq1" "a sequence" } { "seq2" "a sequence" } { "i" "an index" } }
163 { $description "Compares pairs of elements up to the minimum of the sequences' lengths, outputting the first index where the two sequences have non-equal elements, or -1 if all tested elements were equal." } ;
166 { $values { "matrix" "a sequence of equal-length sequences" } { "newmatrix" "a sequence of equal-length sequences" } }
167 { $description "Transposes the matrix; that is, rows become columns and columns become rows." }
168 { $examples { $example "{ { 1 2 3 } { 4 5 6 } } flip ." "{ { 1 4 } { 2 5 } { 3 6 } }" } } ;
171 { $values { "assoc" "a sequence of pairs" } { "keys" "a new sequence" } { "values" "a new sequence" } }
172 { $description "Given a sequence of two-element sequences, outputs a new sequence with the first element of each pair, and a new sequence with the second element of each pair." } ;
175 { $values { "m" "a non-negative integer" } { "n" "a non-negative integer" } { "seq" "a mutable sequence" } }
176 { $description "Exchanges the " { $snippet "m" } "th and " { $snippet "n" } "th elements of " { $snippet "seq" } "." } ;
179 { $values { "key" "an object" } { "assoc" "a sequence of pairs" } { "value" "the associated value, or " { $link f } } }
180 { $description "Searches for a pair whose first element is equal to the key and outputs the second element of the pair. Keys are compared for equality using " { $link = } ". Outputs " { $link f } " if no matching key is found." }
181 { $see-also rassoc } ;
184 { $values { "value" "an object" } { "assoc" "a sequence of pairs" } { "key" "the associated key, or " { $link f } } }
185 { $description "Searches for a pair whose second element is equal to the value and outputs the first element of the pair. Values are compared for equality using " { $link = } ". Outputs " { $link f } " if no matching value is found." }
186 { $see-also rassoc } ;
189 { $values { "seq" "a sequence" } { "pair" "a two-element array" } }
190 { $description "Creates an array holding the first and last element of the sequence." } ;
193 { $values { "seq" "a sequence" } { "n" "a non-negative integer" } { "elt" "an object"} { "padded" "a new sequence" } }
194 { $description "Outputs a new string sequence of " { $snippet "elt" } " repeated, that when appended to " { $snippet "seq" } ", yields a sequence of length " { $snippet "n" } ". If the length of { " { $snippet "seq" } " is greater than " { $snippet "n" } ", this word outputs an empty sequence." } ;
197 { $values { "seq" "a sequence" } { "n" "a non-negative integer" } { "elt" "an object"} { "padded" "a new sequence" } }
198 { $description "Outputs a new sequence consisting of " { $snippet "seq" } " padded on the left with enough repetitions of " { $snippet "elt" } " to have the result be of length " { $snippet "n" } "." }
199 { $examples { $example "{ \"ab\" \"quux\" } [ 5 CHAR: - pad-left print ] each" "---ab\n-quux" } } ;
202 { $values { "seq" "a sequence" } { "n" "a non-negative integer" } { "elt" "an object"} { "padded" "a new sequence" } }
203 { $description "Outputs a new sequence consisting of " { $snippet "seq" } " padded on the right with enough repetitions of " { $snippet "elt" } " to have the result be of length " { $snippet "n" } "." }
204 { $examples { $example "{ \"ab\" \"quux\" } [ 5 CHAR: - pad-right print ] each" "ab---\nquux-" } } ;
207 { $values { "seq1" "a sequence" } { "seq2" "a sequence" } { "?" "a boolean" } }
208 { $description "Tests if the two sequences have the same length and elements. This is weaker than " { $link = } ", since it does not ensure that the sequences are instances of the same class." } ;
211 { $values { "n" "a non-negative integer" } }
212 { $description "Outputs the number of elements on the data stack." } ;
215 { $values { "assoc" "a sequence of quotation pairs" } }
217 "Calls the second quotation in the first pair whose first quotation yields a true value."
219 "The following two phrases are equivalent:"
220 { $code "{ { [ X ] [ Y ] } { [ Z ] [ T ] } } cond" }
221 { $code "X [ Y ] [ Z [ T ] [ no-cond ] if ] if" }
223 { $errors "Throws a " { $link no-cond } " error if none of the test quotations yield a true value." }
227 " { [ dup 0 > ] [ \"positive\" ] }"
228 " { [ dup 0 < ] [ \"negative\" ] }"
229 " { [ dup zero? ] [ \"zero\" ] }"
235 { $description "Throws a " { $link no-cond } " error." }
236 { $error-description "Thrown by " { $link cond } " if none of the test quotations yield a true value. Most uses of " { $link cond } " include a default case where the test quotation is " { $snippet "[ t ]" } "; such a " { $link cond } " form will never throw this error. If you wish to assert that certain conditions are true, and fail otherwise, you can use " { $link cond } " without a default case." } ;
239 { $values { "?" "a boolean" } }
240 { $description "Tests if Factor is running on a Unix-like system. While this is a rather vague notion, one can use it to make certain assumptions about system calls and file structure which are not valid on Windows." } ;